Vikas Jaitak - Academia.edu (original) (raw)

Papers by Vikas Jaitak

Research paper thumbnail of Mandelic acid catalyzed one-pot pseudo three-component synthesis of various trisubstituted methane derivatives at room temperature

Research paper thumbnail of <i>Stevia rebaudiana</i> targeting α-amylase: An <i>in-vitro</i> and <i>in-silico</i> mechanistic study

Diabetes mellitus (DM) is the fastest growing metabolic disorder in the world. Recently, more att... more Diabetes mellitus (DM) is the fastest growing metabolic disorder in the world. Recently, more attention is paid to the study of natural products due to side effects of synthetic drugs. <i>Stevia rebaudiana</i> (Bertoni) is considered an encouraging starting point for the antidiabetic lead development. In the present study, the <i>in vitro</i> α-amylase inhibitory activity of the extracts of <i>S. rebaudiana</i> is investigated. In order to understand the molecular mechanism and future pharmacophore development, <i>in silico</i> study of secondary metabolites isolated from <i>S. rebaudiana</i> was carried out. Results indicated that water extract shows highest α-amylase inhibitory activity as compared to other extracts. Moreover, compound 20 (rebaudioside A) which has been previously reported and isolated from water extract showed the impressive binding profile with α-amylase. Therefore, our study suggests that <i>S. r...

Research paper thumbnail of Isoxazole derivatives as anticancer agent: A review on synthetic strategies, mechanism of action and SAR studies

European Journal of Medicinal Chemistry, 2021

Breast cancer is the second most leading cause of death among women. Multiple drugs have been app... more Breast cancer is the second most leading cause of death among women. Multiple drugs have been approved by FDA for the treatment of BC. The major drawbacks of existing drugs are the development of resistance, toxicity, selectivity problem. The other therapies like hormonal therapy, surgery, radiotherapy, and immune therapy are in use but showed many side effects like bioavailability issues, non-selectivity, pharmacokinetic-pharmacodynamic problems. Therefore, there is an urgent need to develop new moieties that are nonviolent and more effective in the treatment of cancer. Isoxazole derivatives have gain popularity in recent years due to anticancer potential with the least side effects. These derivatives act as an anticancer agent with different mechanisms like inducing apoptosis, aromatase inhibition, disturbing tubulin congregation, topoisomerase inhibition, HDAC inhibition, and ERα inhibition. In this article, we have explored the synthetic strategies, anticancer mechanism of action along with SAR studies of isoxazole derivatives.

Research paper thumbnail of Tetrazoles as anticancer agents: A review on synthetic strategies, mechanism of action and SAR studies

Bioorganic & Medicinal Chemistry, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of Comprehensive temporal reprogramming ensures dynamicity of transcriptomic profile for adaptive response in Taxus contorta

Molecular Genetics and Genomics, 2020

Plants respond to the environmental perturbations by triggering the dynamic changes within the tr... more Plants respond to the environmental perturbations by triggering the dynamic changes within the transcriptome. The assessment of these oscillations within the transcriptome would offer insights into the ecological adaptation of the plants. We evaluated how the transcriptome of Taxus contorta swings under natural conditions to elucidate its adaptive response. Thus, our study provides new insights into the performance of T. contorta under a changing environment during different seasons. The abundance estimation using the RNAseq approach revealed 6727 differentially expressed genes. Comprehensive reprogramming was observed in Taxol biosynthesis, maintenance of redox homeostasis, and generation of effective shield to UV-B, high light intensity, and temperature. Besides differential expression, the alternative splicing (AS) and single nucleotide variations (SNVs) also confer flexibility to the transcriptome of T. contorta. 1936 differentially expressing transcripts were also found to exhibit Differential Exon Usage (DEU) as well as differential SNVs. LC-MS-based untargeted metabolic analysis revealed 7774 ion features, among which around 334 putatively identified metabolites were differentially regulated. Our results showed that the swing and the oscillations of the transcriptome and metabolome of T. contorta ensure adaptability and better survival under changing environment. In addition, varying patterns of AS and SNVs compliment the adaptation provided by differential expression.

Research paper thumbnail of Synthesis, In vitro, and Docking Analysis of C-3 Substituted Coumarin Analogues as Anticancer Agents

Current Computer-Aided Drug Design, 2021

Background: Breast cancer (BC) is a leading cause of cancer-related deaths in women next to skin ... more Background: Breast cancer (BC) is a leading cause of cancer-related deaths in women next to skin cancer. Estrogen receptors (ERs) play an important role in the progression of BC. Current anticancer agents have several drawbacks such as serious side effects and the emergence of resistance to chemotherapeutic drugs. As coumarins possess minimum side effect along with multi-drug reversal activity, it has a tremendous ability to regulate a diverse range of cellular pathways that can be explored for selective anticancer activity. Objectives: Synthesis and evaluation of new coumarin analogues for anti-proliferative activity on human breast cancer cell line MCF-7 along with exploration of binding interaction of the compounds for ER-α target protein by molecular docking. Method: In this study, the anti-proliferative activity of C-3 substituted coumarins analogues (1-17) has been evaluated against estrogen receptor-positive MCF-7 breast cancer cell lines. Molecular interactions and ADME stud...

Research paper thumbnail of Natural products as multidrug resistance modulators in cancer

European Journal of Medicinal Chemistry, 2019

Cancer is a prominent cause of death globally. Currently, many drugs that are in clinical practic... more Cancer is a prominent cause of death globally. Currently, many drugs that are in clinical practice are having a high prevalence of side effect and multidrug resistance. Risk of tumors acquiring resistance to chemotherapy (multidrug resistance) remains a significant hurdle to the successful treatment of various types of cancer. Membrane-embedded drug transporters, generally overexpressed in cancer, are the leading cause among multiple mechanisms of multidrug resistance (MDR). P-glycoprotein (P-gp) also MDR1/ABCB1, multidrug resistance associated protein 1 (MRP1/ABCC1), MRP2 and breast cancer resistance protein (BCRP/ABCG2) are considered to be a prime factor for induction of MDR. To date, several chemical substances have been tested in a number of clinical trials for their MDR modulatory activity which are not having devoid of any side effects that necessitates to find newer and safer way to tackle the current problem of multidrug resistance in cancer. The present study systematically discusses the various classes of natural products i.e flavonoids, alkaloids, terpenoids, coumarins (from plants, marine, and microorganisms) as potential MDR modulators and/or as a source of promising lead compounds. Recently a bisbenzyl isoquinoline alkaloid namely tetrandrine, isolated from Chinese herb Stephania tetrandra (Han-Fang-Chi) is in clinical trials for its MDR reversal activity.

Research paper thumbnail of Stevia rebaudiana targeting α-amylase: An in-vitro and in-silico mechanistic study

Natural Product Research, 2017

Abstract Diabetes mellitus (DM) is the fastest growing metabolic disorder in the world. Recently,... more Abstract Diabetes mellitus (DM) is the fastest growing metabolic disorder in the world. Recently, more attention is paid to the study of natural products due to side effects of synthetic drugs. Stevia rebaudiana (Bertoni) is considered an encouraging starting point for the antidiabetic lead development. In the present study, the in vitro α-amylase inhibitory activity of the extracts of S. rebaudiana is investigated. In order to understand the molecular mechanism and future pharmacophore development, in silico study of secondary metabolites isolated from S. rebaudiana was carried out. Results indicated that water extract shows highest α-amylase inhibitory activity as compared to other extracts. Moreover, compound 20 (rebaudioside A) which has been previously reported and isolated from water extract showed the impressive binding profile with α-amylase. Therefore, our study suggests that S. rebaudiana could be used in the development of therapeutic drugs for the treatment of diabetes.

Research paper thumbnail of Asparagus racemosus (Shatavari) targeting estrogen receptor α: - An in-vitro and in-silico mechanistic study

Natural Product Research, 2018

Breast cancer is a disease where cells in the tissue of the breast, grow and divide without norma... more Breast cancer is a disease where cells in the tissue of the breast, grow and divide without normal control. Breast cancer is second major cause for death in world wide. Importance of natural product increase due to adverse effect of existing synthetic drugs. Asparagus racemosus comprises phytoestrogens which can be used for the treatment of breast cancer. In the current study, In vitro antiproliferative activity of the extracts of A. racemosus is performed in T47D cancer cell lines. Outcomes of the result indicated that aqueous methanol and methanol extract showed excellent antiproliferative activity as compared to bazedoxifene (standard), ethyl acetate and petroleum ether extract. In silico study of reported phytochemical constituents of A. racemosus was performed for understand the molecular mechanism and prospect pharmacophore development. Furthermore compound 26 (rutin) which has been earlier reported and isolated from alcoholic extract exhibited the remarkable binding profile with estrogen receptor α. For that reason our study proposed that A. racemosus could be used as a new source for the treatment of breast cancer.

Research paper thumbnail of Design, synthesis and biological evaluation of novel indole-benzimidazole hybrids targeting estrogen receptor alpha (ER-α)

European Journal of Medicinal Chemistry, 2018

Design, synthesis and biological evaluation of 2-(phenoxymethyl)-5-phenyl-1,3,4-oxadiazole deriva... more Design, synthesis and biological evaluation of 2-(phenoxymethyl)-5-phenyl-1,3,4-oxadiazole derivatives as anti-breast cancer agents,

Research paper thumbnail of Antifungal and repellent activities of the essential oils from three aromatic herbs from western Himalaya

Open Chemistry, 2018

In this investigation we examined the essential oils of three aromatic plants, Zanthoxylum armatu... more In this investigation we examined the essential oils of three aromatic plants, Zanthoxylum armatum, Juniperus communis, and Dysphania ambrosioides, which are used by the local population of the western Himalayan region for medicinal purposes. These plants were studied for their antifungal, larvicidal and biting deterrent activities. Additionally, chemical compositions of the oils were determined by GC-MS and their odor evaluated. The main compounds were 2-undecanone (47.7%) and 1,8-cineol (20.5%) from Z. armatum and α-pinene (43.2%) and limonene (34.7%) from J. communis. p-Cymene (36.3%) and ascardiole (31.2%) were found as the main components of D. ambrosioides essential oil. Antifungal activity was evaluated against three Colletotrichum species. Dyspania ambrosioides oil showed the best activity against these strawberry anthracnose causing fungi. It also demonstrated biting deterrent activity against Aedes aegypti similar to DEET as positive control, whereas Z. armatum and J. comm...

Research paper thumbnail of Essential Oils: An Impending Substitute of Synthetic Antimicrobial Agents to Overcome Antimicrobial Resistance

Current Drug Targets, 2019

Antimicrobial resistance (AMR) is an emerging problem in the world that has a significant impact ... more Antimicrobial resistance (AMR) is an emerging problem in the world that has a significant impact on our society. AMR made conventional drugs futile against microorganisms and diseases untreatable. Plant-derived medicines are considered to be safe alternatives as compared to synthetic drugs. Active ingredients and the mixtures of these natural medicines have been used for centuries, due to their easy availability, low cost, and negligible side effects. Essential oils (EOs) are the secondary metabolites that are produced by aromatic plants to protect them from microorganisms. However, these EOs and their constituents have shown good fighting potential against drug-resistant pathogens. These oils have been proved extremely effective antimicrobial agents in comparison to antibiotics. Also, the combination of synthetic drugs with EOs or their components improve their efficacy. So, EOs can be established as an alternative to synthetic antimicrobial agents to eradicate tough form of infect...

Research paper thumbnail of Biological Activity of Bunium persicum Essential Oil from Western Himalaya

Planta Medica International Open, 2017

The essential oil of Bunium persicum collected from cultivated sources in the cold desert area of... more The essential oil of Bunium persicum collected from cultivated sources in the cold desert area of Lahaul-Spiti is described for its antimicrobial, larvicidal, and biting deterrent activities. Additionally, odor characterization is given. The chemical composition of the essential oil was analyzed by simultaneous GC-MS and GC-FID. γ-Terpinene and p-cymene were found to be the major compounds. Antibacterial testing by an agar dilution assay revealed low activity of the oil against all tested bacteria. Antifungal activity was evaluated against Candida albicans as well as three species of the strawberry anthracnose causing plant pathogen Colletotrichum. Bunium persicum essential oil demonstrated antifungal activity against all four pathogens. Biting deterrent activity against Aedes aegypti was greater than the solvent control, but significantly lower than DEET. The essential oil of B. persicum exhibited larvicidal activity with an LC50 value of 58.6 ppm against Ae. aegypti larvae.

Research paper thumbnail of Recent developments of C-4 substituted coumarin derivatives as anticancer agents

European Journal of Medicinal Chemistry, 2016

Cancer is a prominent cause of death in global. Currently, the numbers of drugs that are in clini... more Cancer is a prominent cause of death in global. Currently, the numbers of drugs that are in clinical practice are having a high prevalence of side effect and multidrug resistance. Researchers have made an attempt to expand a suitable anticancer drug that has no MDR and side effect. Coumarin scaffold became an attractive subject due to their broad spectrum of pharmacological activities. Coumarin derivatives extensively explored for anticancer activities as it possesses minimum side effect along with multi-drug reversal activity. Coumarin derivatives can act by various mechanisms on different tumor cell lines depending on substitution pattern of the core structure of coumarin. Substitution on coumarin nucleus leads to the search for more potent compounds. In this review, we have made an effort to give a synthetic strategy for the preparation of C-4 substituted coumarin derivatives as anticancer agents based on their mechanism of action and also discuss the SAR of the most active compound.

Research paper thumbnail of Synthesis of rebaudioside A from stevioside and their interaction model with hTAS2R4 bitter taste receptor

Phytochemistry, 2016

Steviol glycosides (SG's) from Stevia rebaudiana (Bertoni) have been used as a natural low-calori... more Steviol glycosides (SG's) from Stevia rebaudiana (Bertoni) have been used as a natural low-calorie sweeteners. Its aftertaste bitterness restricts its use for human consumption and limits its application in food and pharmaceutical products. In present study, we have performed computational analysis in order to investigate the interaction of two major constituents of SG's against homology model of the hTAS2R4 receptor. Molecular simulation study was performed using stevioside and rebaudioside A revealed that, sugar moiety at the C-3 00 position in rebaudioside A causes restriction of its entry into the receptor site thereby unable to trigger the bitter reception signaling cascade. Encouraged by the current finding, we have also developed a greener route using b-1,3-glucanase from Irpex lacteus for the synthesis of de-bittered rebaudioside A from stevioside. The rebaudioside A obtained was of high quality with percent conversion of 62.5%. The results here reported could be used for the synthesis of rebaudioside A which have large application in food and pharmaceutical industry.

Research paper thumbnail of Photoprotective, antioxidant screening and new ester from dry root extracts of Potentilla atrosanguinea (Himalayan cinquefoil)

South African Journal of Botany, 2016

In vitro photoprotective and antioxidant activities of dried aqueous-methanolic (H 2 O/MeOH) crud... more In vitro photoprotective and antioxidant activities of dried aqueous-methanolic (H 2 O/MeOH) crude extract and ethyl acetate (EtOAc), n-butanol (n-BuOH) as well as aqueous (H 2 O) fractions of roots of western Himalayan plant Potentilla atrosanguinea (Himalayan cinquefoil) were evaluated. The ability of protection against UVB region followed the trend EtOAc N n-BuOH N H 2 O/MeOH N H 2 O. Total phenol content of crude H 2 O/MeOH extract was found to be 429.808 mg GAE/g. The H 2 O/MeOH crude extract showed highest antioxidant of DPPH radical scavenging, superoxide anion radical scavenging and cupric ion reducing of 90.04, 78.86 and 88.64% respectively at 200 μg/mL. One new compound methyl pentatetraconta-30,32,34,36,38,40,42-heptaenoate (PA-1) along with a known pentadecylbutyrate (PA-2) was isolated by column chromatography. Results indicated the importance of root extracts as photoprotective agents in sunscreen preparation in the pharmaceutical industry and considered as a natural source of antioxidants.

Research paper thumbnail of Chemical composition and antibacterial activity of essential oils of<i>Lantana camara</i>,<i>Ageratum houstonianum</i>and<i>Eupatorium adenophorum</i>

Pharmaceutical Biology, Apr 28, 2010

View related articles Citing articles: 40 View citing articles Recently, plant secondary metaboli... more View related articles Citing articles: 40 View citing articles Recently, plant secondary metabolites (PSM), particularly essential oils, have evoked considerable interest as food and feed additives and as an alternative to antibiotics and synthetic antioxidants (

Research paper thumbnail of Enviornmentally benign Michael and Claisen Schmidt reaction of aromatic carbonyl compounds by alkaline polyionic resin

Indian Journal of Chemistry Section B, Aug 2, 2013

A regioselective Michael reaction between aryl methyl ketones and α,β-unsaturated compounds has b... more A regioselective Michael reaction between aryl methyl ketones and α,β-unsaturated compounds has been carried out using basic polyionic resin as a reusable reagent. Results indicate that the reaction proceeds in consecutive manner as double Michael (27-65%) and triple Michael (40-45%) products with overall yields of 55-80%. Moreover, A-2XMP resin has also been applied on Claisen Schmidt condensations of aromatic aldehydes and ketones (acyclic as well as cyclic) under different reaction conditions yielding dehydrated products in 82-94% yield. The reactions give an opportunity for easy separation, reusability of polyionic resin and easy purification of products in continuous or multiple processing of organic compounds.

Research paper thumbnail of Indole Derivatives as Anticancer Agents for Breast Cancer Therapy: A Review

Anti-Cancer Agents in Medicinal Chemistry, 2015

Research paper thumbnail of Molecular docking study of natural alkaloids as multi-targeted hedgehog pathway inhibitors in cancer stem cell therapy

Computational Biology and Chemistry, 2016

Cancer is responsible for millions of deaths throughout the world every year. Increased understan... more Cancer is responsible for millions of deaths throughout the world every year. Increased understanding as well as advancements in the therapeutic aspect seems suboptimal to restrict the huge deaths associated with cancer. The major cause responsible for this is high resistance as well as relapse rate associated with cancers. Several evidences indicated that cancer stem cells (CSC) are mainly responsible for the resistance and relapses associated with cancer. Furthermore, agents targeting a single protein seem to have higher chances of resistance than multitargeting drugs. According to the concept of network model, partial inhibition of multiple targets is more productive than single hit agents. Thus, by fusing both the premises that CSC and single hit anticancer drugs, both are responsible for cancer related resistances and screened alkaloids for the search of leads having CSC targeting ability as well as the capability to modulating multiple target proteins. The in silico experimental data indicated that emetine and cortistatin have the ability to modulate hedgehog (Hh) pathway by binding to sonic hedgehog (Hh), smoothened (Smo) and Gli protein, involved in maintenance CSCs. Furthermore, solamargine, solasonine and tylophorine are also seems to be good lead molecules targeting towards CSCs by modulating Hh pathway. Except solamargine and solasonine, other best lead molecules also showed acceptable in silico ADME profile. The predicted lead molecules can be suitably modified to get multitargeting CSC targeting agent to get rid of associate resistances.

Research paper thumbnail of Mandelic acid catalyzed one-pot pseudo three-component synthesis of various trisubstituted methane derivatives at room temperature

Research paper thumbnail of <i>Stevia rebaudiana</i> targeting α-amylase: An <i>in-vitro</i> and <i>in-silico</i> mechanistic study

Diabetes mellitus (DM) is the fastest growing metabolic disorder in the world. Recently, more att... more Diabetes mellitus (DM) is the fastest growing metabolic disorder in the world. Recently, more attention is paid to the study of natural products due to side effects of synthetic drugs. <i>Stevia rebaudiana</i> (Bertoni) is considered an encouraging starting point for the antidiabetic lead development. In the present study, the <i>in vitro</i> α-amylase inhibitory activity of the extracts of <i>S. rebaudiana</i> is investigated. In order to understand the molecular mechanism and future pharmacophore development, <i>in silico</i> study of secondary metabolites isolated from <i>S. rebaudiana</i> was carried out. Results indicated that water extract shows highest α-amylase inhibitory activity as compared to other extracts. Moreover, compound 20 (rebaudioside A) which has been previously reported and isolated from water extract showed the impressive binding profile with α-amylase. Therefore, our study suggests that <i>S. r...

Research paper thumbnail of Isoxazole derivatives as anticancer agent: A review on synthetic strategies, mechanism of action and SAR studies

European Journal of Medicinal Chemistry, 2021

Breast cancer is the second most leading cause of death among women. Multiple drugs have been app... more Breast cancer is the second most leading cause of death among women. Multiple drugs have been approved by FDA for the treatment of BC. The major drawbacks of existing drugs are the development of resistance, toxicity, selectivity problem. The other therapies like hormonal therapy, surgery, radiotherapy, and immune therapy are in use but showed many side effects like bioavailability issues, non-selectivity, pharmacokinetic-pharmacodynamic problems. Therefore, there is an urgent need to develop new moieties that are nonviolent and more effective in the treatment of cancer. Isoxazole derivatives have gain popularity in recent years due to anticancer potential with the least side effects. These derivatives act as an anticancer agent with different mechanisms like inducing apoptosis, aromatase inhibition, disturbing tubulin congregation, topoisomerase inhibition, HDAC inhibition, and ERα inhibition. In this article, we have explored the synthetic strategies, anticancer mechanism of action along with SAR studies of isoxazole derivatives.

Research paper thumbnail of Tetrazoles as anticancer agents: A review on synthetic strategies, mechanism of action and SAR studies

Bioorganic & Medicinal Chemistry, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of Comprehensive temporal reprogramming ensures dynamicity of transcriptomic profile for adaptive response in Taxus contorta

Molecular Genetics and Genomics, 2020

Plants respond to the environmental perturbations by triggering the dynamic changes within the tr... more Plants respond to the environmental perturbations by triggering the dynamic changes within the transcriptome. The assessment of these oscillations within the transcriptome would offer insights into the ecological adaptation of the plants. We evaluated how the transcriptome of Taxus contorta swings under natural conditions to elucidate its adaptive response. Thus, our study provides new insights into the performance of T. contorta under a changing environment during different seasons. The abundance estimation using the RNAseq approach revealed 6727 differentially expressed genes. Comprehensive reprogramming was observed in Taxol biosynthesis, maintenance of redox homeostasis, and generation of effective shield to UV-B, high light intensity, and temperature. Besides differential expression, the alternative splicing (AS) and single nucleotide variations (SNVs) also confer flexibility to the transcriptome of T. contorta. 1936 differentially expressing transcripts were also found to exhibit Differential Exon Usage (DEU) as well as differential SNVs. LC-MS-based untargeted metabolic analysis revealed 7774 ion features, among which around 334 putatively identified metabolites were differentially regulated. Our results showed that the swing and the oscillations of the transcriptome and metabolome of T. contorta ensure adaptability and better survival under changing environment. In addition, varying patterns of AS and SNVs compliment the adaptation provided by differential expression.

Research paper thumbnail of Synthesis, In vitro, and Docking Analysis of C-3 Substituted Coumarin Analogues as Anticancer Agents

Current Computer-Aided Drug Design, 2021

Background: Breast cancer (BC) is a leading cause of cancer-related deaths in women next to skin ... more Background: Breast cancer (BC) is a leading cause of cancer-related deaths in women next to skin cancer. Estrogen receptors (ERs) play an important role in the progression of BC. Current anticancer agents have several drawbacks such as serious side effects and the emergence of resistance to chemotherapeutic drugs. As coumarins possess minimum side effect along with multi-drug reversal activity, it has a tremendous ability to regulate a diverse range of cellular pathways that can be explored for selective anticancer activity. Objectives: Synthesis and evaluation of new coumarin analogues for anti-proliferative activity on human breast cancer cell line MCF-7 along with exploration of binding interaction of the compounds for ER-α target protein by molecular docking. Method: In this study, the anti-proliferative activity of C-3 substituted coumarins analogues (1-17) has been evaluated against estrogen receptor-positive MCF-7 breast cancer cell lines. Molecular interactions and ADME stud...

Research paper thumbnail of Natural products as multidrug resistance modulators in cancer

European Journal of Medicinal Chemistry, 2019

Cancer is a prominent cause of death globally. Currently, many drugs that are in clinical practic... more Cancer is a prominent cause of death globally. Currently, many drugs that are in clinical practice are having a high prevalence of side effect and multidrug resistance. Risk of tumors acquiring resistance to chemotherapy (multidrug resistance) remains a significant hurdle to the successful treatment of various types of cancer. Membrane-embedded drug transporters, generally overexpressed in cancer, are the leading cause among multiple mechanisms of multidrug resistance (MDR). P-glycoprotein (P-gp) also MDR1/ABCB1, multidrug resistance associated protein 1 (MRP1/ABCC1), MRP2 and breast cancer resistance protein (BCRP/ABCG2) are considered to be a prime factor for induction of MDR. To date, several chemical substances have been tested in a number of clinical trials for their MDR modulatory activity which are not having devoid of any side effects that necessitates to find newer and safer way to tackle the current problem of multidrug resistance in cancer. The present study systematically discusses the various classes of natural products i.e flavonoids, alkaloids, terpenoids, coumarins (from plants, marine, and microorganisms) as potential MDR modulators and/or as a source of promising lead compounds. Recently a bisbenzyl isoquinoline alkaloid namely tetrandrine, isolated from Chinese herb Stephania tetrandra (Han-Fang-Chi) is in clinical trials for its MDR reversal activity.

Research paper thumbnail of Stevia rebaudiana targeting α-amylase: An in-vitro and in-silico mechanistic study

Natural Product Research, 2017

Abstract Diabetes mellitus (DM) is the fastest growing metabolic disorder in the world. Recently,... more Abstract Diabetes mellitus (DM) is the fastest growing metabolic disorder in the world. Recently, more attention is paid to the study of natural products due to side effects of synthetic drugs. Stevia rebaudiana (Bertoni) is considered an encouraging starting point for the antidiabetic lead development. In the present study, the in vitro α-amylase inhibitory activity of the extracts of S. rebaudiana is investigated. In order to understand the molecular mechanism and future pharmacophore development, in silico study of secondary metabolites isolated from S. rebaudiana was carried out. Results indicated that water extract shows highest α-amylase inhibitory activity as compared to other extracts. Moreover, compound 20 (rebaudioside A) which has been previously reported and isolated from water extract showed the impressive binding profile with α-amylase. Therefore, our study suggests that S. rebaudiana could be used in the development of therapeutic drugs for the treatment of diabetes.

Research paper thumbnail of Asparagus racemosus (Shatavari) targeting estrogen receptor α: - An in-vitro and in-silico mechanistic study

Natural Product Research, 2018

Breast cancer is a disease where cells in the tissue of the breast, grow and divide without norma... more Breast cancer is a disease where cells in the tissue of the breast, grow and divide without normal control. Breast cancer is second major cause for death in world wide. Importance of natural product increase due to adverse effect of existing synthetic drugs. Asparagus racemosus comprises phytoestrogens which can be used for the treatment of breast cancer. In the current study, In vitro antiproliferative activity of the extracts of A. racemosus is performed in T47D cancer cell lines. Outcomes of the result indicated that aqueous methanol and methanol extract showed excellent antiproliferative activity as compared to bazedoxifene (standard), ethyl acetate and petroleum ether extract. In silico study of reported phytochemical constituents of A. racemosus was performed for understand the molecular mechanism and prospect pharmacophore development. Furthermore compound 26 (rutin) which has been earlier reported and isolated from alcoholic extract exhibited the remarkable binding profile with estrogen receptor α. For that reason our study proposed that A. racemosus could be used as a new source for the treatment of breast cancer.

Research paper thumbnail of Design, synthesis and biological evaluation of novel indole-benzimidazole hybrids targeting estrogen receptor alpha (ER-α)

European Journal of Medicinal Chemistry, 2018

Design, synthesis and biological evaluation of 2-(phenoxymethyl)-5-phenyl-1,3,4-oxadiazole deriva... more Design, synthesis and biological evaluation of 2-(phenoxymethyl)-5-phenyl-1,3,4-oxadiazole derivatives as anti-breast cancer agents,

Research paper thumbnail of Antifungal and repellent activities of the essential oils from three aromatic herbs from western Himalaya

Open Chemistry, 2018

In this investigation we examined the essential oils of three aromatic plants, Zanthoxylum armatu... more In this investigation we examined the essential oils of three aromatic plants, Zanthoxylum armatum, Juniperus communis, and Dysphania ambrosioides, which are used by the local population of the western Himalayan region for medicinal purposes. These plants were studied for their antifungal, larvicidal and biting deterrent activities. Additionally, chemical compositions of the oils were determined by GC-MS and their odor evaluated. The main compounds were 2-undecanone (47.7%) and 1,8-cineol (20.5%) from Z. armatum and α-pinene (43.2%) and limonene (34.7%) from J. communis. p-Cymene (36.3%) and ascardiole (31.2%) were found as the main components of D. ambrosioides essential oil. Antifungal activity was evaluated against three Colletotrichum species. Dyspania ambrosioides oil showed the best activity against these strawberry anthracnose causing fungi. It also demonstrated biting deterrent activity against Aedes aegypti similar to DEET as positive control, whereas Z. armatum and J. comm...

Research paper thumbnail of Essential Oils: An Impending Substitute of Synthetic Antimicrobial Agents to Overcome Antimicrobial Resistance

Current Drug Targets, 2019

Antimicrobial resistance (AMR) is an emerging problem in the world that has a significant impact ... more Antimicrobial resistance (AMR) is an emerging problem in the world that has a significant impact on our society. AMR made conventional drugs futile against microorganisms and diseases untreatable. Plant-derived medicines are considered to be safe alternatives as compared to synthetic drugs. Active ingredients and the mixtures of these natural medicines have been used for centuries, due to their easy availability, low cost, and negligible side effects. Essential oils (EOs) are the secondary metabolites that are produced by aromatic plants to protect them from microorganisms. However, these EOs and their constituents have shown good fighting potential against drug-resistant pathogens. These oils have been proved extremely effective antimicrobial agents in comparison to antibiotics. Also, the combination of synthetic drugs with EOs or their components improve their efficacy. So, EOs can be established as an alternative to synthetic antimicrobial agents to eradicate tough form of infect...

Research paper thumbnail of Biological Activity of Bunium persicum Essential Oil from Western Himalaya

Planta Medica International Open, 2017

The essential oil of Bunium persicum collected from cultivated sources in the cold desert area of... more The essential oil of Bunium persicum collected from cultivated sources in the cold desert area of Lahaul-Spiti is described for its antimicrobial, larvicidal, and biting deterrent activities. Additionally, odor characterization is given. The chemical composition of the essential oil was analyzed by simultaneous GC-MS and GC-FID. γ-Terpinene and p-cymene were found to be the major compounds. Antibacterial testing by an agar dilution assay revealed low activity of the oil against all tested bacteria. Antifungal activity was evaluated against Candida albicans as well as three species of the strawberry anthracnose causing plant pathogen Colletotrichum. Bunium persicum essential oil demonstrated antifungal activity against all four pathogens. Biting deterrent activity against Aedes aegypti was greater than the solvent control, but significantly lower than DEET. The essential oil of B. persicum exhibited larvicidal activity with an LC50 value of 58.6 ppm against Ae. aegypti larvae.

Research paper thumbnail of Recent developments of C-4 substituted coumarin derivatives as anticancer agents

European Journal of Medicinal Chemistry, 2016

Cancer is a prominent cause of death in global. Currently, the numbers of drugs that are in clini... more Cancer is a prominent cause of death in global. Currently, the numbers of drugs that are in clinical practice are having a high prevalence of side effect and multidrug resistance. Researchers have made an attempt to expand a suitable anticancer drug that has no MDR and side effect. Coumarin scaffold became an attractive subject due to their broad spectrum of pharmacological activities. Coumarin derivatives extensively explored for anticancer activities as it possesses minimum side effect along with multi-drug reversal activity. Coumarin derivatives can act by various mechanisms on different tumor cell lines depending on substitution pattern of the core structure of coumarin. Substitution on coumarin nucleus leads to the search for more potent compounds. In this review, we have made an effort to give a synthetic strategy for the preparation of C-4 substituted coumarin derivatives as anticancer agents based on their mechanism of action and also discuss the SAR of the most active compound.

Research paper thumbnail of Synthesis of rebaudioside A from stevioside and their interaction model with hTAS2R4 bitter taste receptor

Phytochemistry, 2016

Steviol glycosides (SG's) from Stevia rebaudiana (Bertoni) have been used as a natural low-calori... more Steviol glycosides (SG's) from Stevia rebaudiana (Bertoni) have been used as a natural low-calorie sweeteners. Its aftertaste bitterness restricts its use for human consumption and limits its application in food and pharmaceutical products. In present study, we have performed computational analysis in order to investigate the interaction of two major constituents of SG's against homology model of the hTAS2R4 receptor. Molecular simulation study was performed using stevioside and rebaudioside A revealed that, sugar moiety at the C-3 00 position in rebaudioside A causes restriction of its entry into the receptor site thereby unable to trigger the bitter reception signaling cascade. Encouraged by the current finding, we have also developed a greener route using b-1,3-glucanase from Irpex lacteus for the synthesis of de-bittered rebaudioside A from stevioside. The rebaudioside A obtained was of high quality with percent conversion of 62.5%. The results here reported could be used for the synthesis of rebaudioside A which have large application in food and pharmaceutical industry.

Research paper thumbnail of Photoprotective, antioxidant screening and new ester from dry root extracts of Potentilla atrosanguinea (Himalayan cinquefoil)

South African Journal of Botany, 2016

In vitro photoprotective and antioxidant activities of dried aqueous-methanolic (H 2 O/MeOH) crud... more In vitro photoprotective and antioxidant activities of dried aqueous-methanolic (H 2 O/MeOH) crude extract and ethyl acetate (EtOAc), n-butanol (n-BuOH) as well as aqueous (H 2 O) fractions of roots of western Himalayan plant Potentilla atrosanguinea (Himalayan cinquefoil) were evaluated. The ability of protection against UVB region followed the trend EtOAc N n-BuOH N H 2 O/MeOH N H 2 O. Total phenol content of crude H 2 O/MeOH extract was found to be 429.808 mg GAE/g. The H 2 O/MeOH crude extract showed highest antioxidant of DPPH radical scavenging, superoxide anion radical scavenging and cupric ion reducing of 90.04, 78.86 and 88.64% respectively at 200 μg/mL. One new compound methyl pentatetraconta-30,32,34,36,38,40,42-heptaenoate (PA-1) along with a known pentadecylbutyrate (PA-2) was isolated by column chromatography. Results indicated the importance of root extracts as photoprotective agents in sunscreen preparation in the pharmaceutical industry and considered as a natural source of antioxidants.

Research paper thumbnail of Chemical composition and antibacterial activity of essential oils of<i>Lantana camara</i>,<i>Ageratum houstonianum</i>and<i>Eupatorium adenophorum</i>

Pharmaceutical Biology, Apr 28, 2010

View related articles Citing articles: 40 View citing articles Recently, plant secondary metaboli... more View related articles Citing articles: 40 View citing articles Recently, plant secondary metabolites (PSM), particularly essential oils, have evoked considerable interest as food and feed additives and as an alternative to antibiotics and synthetic antioxidants (

Research paper thumbnail of Enviornmentally benign Michael and Claisen Schmidt reaction of aromatic carbonyl compounds by alkaline polyionic resin

Indian Journal of Chemistry Section B, Aug 2, 2013

A regioselective Michael reaction between aryl methyl ketones and α,β-unsaturated compounds has b... more A regioselective Michael reaction between aryl methyl ketones and α,β-unsaturated compounds has been carried out using basic polyionic resin as a reusable reagent. Results indicate that the reaction proceeds in consecutive manner as double Michael (27-65%) and triple Michael (40-45%) products with overall yields of 55-80%. Moreover, A-2XMP resin has also been applied on Claisen Schmidt condensations of aromatic aldehydes and ketones (acyclic as well as cyclic) under different reaction conditions yielding dehydrated products in 82-94% yield. The reactions give an opportunity for easy separation, reusability of polyionic resin and easy purification of products in continuous or multiple processing of organic compounds.

Research paper thumbnail of Indole Derivatives as Anticancer Agents for Breast Cancer Therapy: A Review

Anti-Cancer Agents in Medicinal Chemistry, 2015

Research paper thumbnail of Molecular docking study of natural alkaloids as multi-targeted hedgehog pathway inhibitors in cancer stem cell therapy

Computational Biology and Chemistry, 2016

Cancer is responsible for millions of deaths throughout the world every year. Increased understan... more Cancer is responsible for millions of deaths throughout the world every year. Increased understanding as well as advancements in the therapeutic aspect seems suboptimal to restrict the huge deaths associated with cancer. The major cause responsible for this is high resistance as well as relapse rate associated with cancers. Several evidences indicated that cancer stem cells (CSC) are mainly responsible for the resistance and relapses associated with cancer. Furthermore, agents targeting a single protein seem to have higher chances of resistance than multitargeting drugs. According to the concept of network model, partial inhibition of multiple targets is more productive than single hit agents. Thus, by fusing both the premises that CSC and single hit anticancer drugs, both are responsible for cancer related resistances and screened alkaloids for the search of leads having CSC targeting ability as well as the capability to modulating multiple target proteins. The in silico experimental data indicated that emetine and cortistatin have the ability to modulate hedgehog (Hh) pathway by binding to sonic hedgehog (Hh), smoothened (Smo) and Gli protein, involved in maintenance CSCs. Furthermore, solamargine, solasonine and tylophorine are also seems to be good lead molecules targeting towards CSCs by modulating Hh pathway. Except solamargine and solasonine, other best lead molecules also showed acceptable in silico ADME profile. The predicted lead molecules can be suitably modified to get multitargeting CSC targeting agent to get rid of associate resistances.