Mohammed Aldholmi - Academia.edu (original) (raw)
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Papers by Mohammed Aldholmi
lwt food science and technology, 2022
The study reports a novel, green, and effective ASE (accelerated solvent extraction) technique wi... more The study reports a novel, green, and effective ASE (accelerated solvent extraction) technique with a green, fast, and sensitive method of UPLC-MS/MS for a comprehensive characterization of whole mango fruit (epi-, endo-, Mesocarp, seed) under solvent, temperature, and origin effect in order to determine the inter- and intra-variation of MG(Mangiferin)-amount in fresh mango fruit. The ASE-MD (method development) showed the highest extract yield and more MG-amount in H2O at 80 ◦C (mesocarp fruit part). For MG-quantification, a fast and sensitive UPLC-MS/MS method (RT = 0.31/runtime = 1 min; m/z 421.10 → 81.00 amu) was developed. The UPLC-MS/MS-MV validated the method with high accuracy, precision, and r2 = 0.998. The intra-variation for MG was: mesocarp > endocarp > epicarp > seed. The inter-variation (MG-amount (mg/10g) in 12-mango cultivars) based on the sum of MG-amount/12-mango fruits parts: mesocarp (12.42)> epicarp (10.92)> endocarp (10.47)> seed (8.70) whereas, based on the largest MG-amount/individual mango fruit it was: mesocarp (5/12 fruits)> endocarp (4/12 fruits)> epicarp (3/12 fruits)> seed (0/12). The statistical models for PCA, K-mean cluster, and Pearson’s analysis revealed significant correlation (P ≤ 0.005) for origin*solvent*temperature Vs MG-amount with a nonsignificant correlation for origin*MG-amount Vs extract yield. The ASE-UPLC-MS/MS comprehensively characterized inter-, and intra-variation of MG in different parts of mango fruit.
Plants
This study evaluates the quality variation for twenty-seven capsicum fruit (CF) samples, in terms... more This study evaluates the quality variation for twenty-seven capsicum fruit (CF) samples, in terms of their volatile oil composition and biological activities. The GCMS analysis revealed the presence of seventy one chemical compounds from different chemical classes with an average (%) composition of: 26.13 (alcohols) > 18.82 (hydrocarbons) > 14.97 (esters) > 3.08 (ketones) > 1.14 (others) > 1.07 (acids) > 0.72 (sugar) > 0.42 (aldehydes) > 0.15 (amino compounds). Alcohols and hydrocarbons were the most abundant in these CF samples with 1-Decanol, 2-octyl- and docosanoic acid, docosyl ester as the major components, respectively. The % inhibition in cytotoxicity assays was observed in the range of 9–47 (MCF7) and 4–41 (HCT116) whereas, the zone of inhibition (mm) for the antimicrobial activity was found to be 0.0–17 (P. aeruginosa) > 0.0–13 (E. coli and S. aureus). Moreover, the samples with the largest zone of inhibition in the agar-well-diffusion method (C16...
Angewandte Chemie
By limiting the nitrogen source to glutamic acid, we isolated cyclic peptides from Euglena gracil... more By limiting the nitrogen source to glutamic acid, we isolated cyclic peptides from Euglena gracilis containing asparagine and non-proteinogenic amino acids. Structure elucidation was accomplished through spectroscopic methods, mass spectrometry and chemical degradation. The euglenatides potently inhibit pathogenic fungi and cancer cell lines e.g., euglenatide B exhibiting IC50 values of 4.3 M in ketoconazole resistant Aspergillus fumigatus and 0.29 M in MCF-7 breast cancer cells. In an unprecedented convergence of non-ribosomal peptide synthetase and polyketide synthase assembly-line biosynthesis between unicellular species and the metazoan kingdom, euglenatides bear resemblance to nemamides from Caenorhabditis elegans and inhibited both producing organisms E. gracilis and C. elegans. By molecular network analysis, we detected over forty euglenatide-like metabolites in E. gracilis, E. sanguinea and E. mutabilis, suggesting an important biological role for these natural products.
Food Additives & Contaminants: Part B, 2022
The journal of APJCP (Asian Pacific Journal of Cancer Prevention) focuses to gather relevant and ... more The journal of APJCP (Asian Pacific Journal of Cancer Prevention) focuses to gather relevant and up-to-date novel information's related to cancer sciences. The research methodologies and approaches adopted by the researcher are prone to variation which may be desirable in the context of novel scientific findings however, the reproducibility for these studies needs to be unified and assured. The reproducibility issues are highly concerned when preclinical studies are reported in cancer, for natural products in particular. The natural products and medicinal plants are prone to a wide variation in terms of phytochemistry and phyto-pharmacology, ultimately affecting the end results for cancer studies. Hence the need for specific guidelines to adopt a best-practice in cancer research are utmost essential. The current AIMRDA guidelines aims to develop a consensus-based tool in order to enhance the quality and assure the reproducibility of studies reporting natural products in cancer prevention. A core working committee of the experts developed an initial draft for the guidelines where more focus was kept for the inclusion of specific items not covered in previous published tools. The initial draft was peer-reviewed, experts-views provided, and improved by a scientific committee comprising of field research experts, editorial experts of different journals, and academics working in different organization worldwide. The feedback from continuous online meetings, mail communications, and webinars resulted a final draft in the shape of a checklist tool, covering the best practices related to the field of natural products research in cancer prevention and treatment. It is mandatory for the authors to read and follow the AIMRDA tool, and be aware of the good-practices to be followed in cancer research prior to any submission to APJCP. Though the tool is developed based on experts in the field, it needs to be further updated and validated in practice via implementation in the field.
Microbial natural products represent a significant portion of small-molecule drugs approved for c... more Microbial natural products represent a significant portion of small-molecule drugs approved for clinical use, especially as anti-infective and anticancer agents. Nevertheless, most clinically used anti-infective and anticancer agents suffer from resistance and other drawbacks such as adverse effects, drug interactions and poor pharmacokinetic properties. Some of the main challenges in the natural product discovery field are the high rediscovery rates and low yield of natural products. One of the factors contributing to this problem is the fact that the genes responsible for the production of a great number of natural products are transcriptionally inactive (silent) or poorly expressed under laboratory conditions, resulting in undetectable concentrations of the corresponding products. Therefore, this project aimed at activating natural product genes in Euglena microalgae, Aspergillus fungi and actinomycete bacteria through nutritional and epigenetic manipulation. Nutritional manipula...
A novel, green and eco-friendly, cost-effective, fast, and reliable high energy ultrasonication (... more A novel, green and eco-friendly, cost-effective, fast, and reliable high energy ultrasonication (US) extraction with UHPLC-MSMS quantification of Glycyrrhizic acid (GZA) is reported herein for the first time. The study provides useful insights regarding the effect of US-factors with statistical analysis and mechanisms, involved in GZA-extraction and analysis. An US-extraction method (US-MD) was developed using three levels of US factors: solvent (AC (acetone), EtOH (ethanol), H2O (water)), time (1, 2, 3 min), amplitude (30, 40, 50%), pulse (10/0.5, 20/0.5, 30/0.5 sec), particle size (0.5, 1, 1.4 mm), and temperature (20, 30, 40 °C). The US-MD was further validated (US-MV) with high accuracy 98.96 ±6.82 and r2=0.995 whereas, an in-house analytical method (UHPLC-MSMS) was developed and validated to quantify the GZAamount. UHPLCMSMS-MD resulted in a retention time of 0.31 min with MSMS (821.400>351.200) in a 1 min run time whereas, UHPLCMSMS-MV showed high accuracy and precision wit...
Ultrasonics Sonochemistry
Highlights • Green and novel US-extraction and UHPLC-MSMS analysis method was developed/validated... more Highlights • Green and novel US-extraction and UHPLC-MSMS analysis method was developed/validated.• Temperatures, solvents, amplitudes, pulse rates, and particle sizes were correlated with GZA.• Cavitation, turbulence, sonocapillary, and sonochemical effects were observedduring US-process.• A linear increase was observed with an increase in US-factors with an exception of particle size.• Solvent showed more correlation with GZA whereas, particle size more towards extract yield.
In this review, we discuss novel natural products discovered within the last decade that are repo... more In this review, we discuss novel natural products discovered within the last decade that are reported to have antifungal activity against pathogenic species. Nearly a hundred natural products were identified that originate from bacteria, alga, fungi, sponges and plants. Fungi were the most prolific source of antifungal compounds discovered during the period of review. The structural diversity of these antifungal leads encompasses all the major classes of natural products including polyketides, shikimate metabolites, terpenoids, alkaloids and peptides.
The Journal of Antibiotics
lwt food science and technology, 2022
The study reports a novel, green, and effective ASE (accelerated solvent extraction) technique wi... more The study reports a novel, green, and effective ASE (accelerated solvent extraction) technique with a green, fast, and sensitive method of UPLC-MS/MS for a comprehensive characterization of whole mango fruit (epi-, endo-, Mesocarp, seed) under solvent, temperature, and origin effect in order to determine the inter- and intra-variation of MG(Mangiferin)-amount in fresh mango fruit. The ASE-MD (method development) showed the highest extract yield and more MG-amount in H2O at 80 ◦C (mesocarp fruit part). For MG-quantification, a fast and sensitive UPLC-MS/MS method (RT = 0.31/runtime = 1 min; m/z 421.10 → 81.00 amu) was developed. The UPLC-MS/MS-MV validated the method with high accuracy, precision, and r2 = 0.998. The intra-variation for MG was: mesocarp > endocarp > epicarp > seed. The inter-variation (MG-amount (mg/10g) in 12-mango cultivars) based on the sum of MG-amount/12-mango fruits parts: mesocarp (12.42)> epicarp (10.92)> endocarp (10.47)> seed (8.70) whereas, based on the largest MG-amount/individual mango fruit it was: mesocarp (5/12 fruits)> endocarp (4/12 fruits)> epicarp (3/12 fruits)> seed (0/12). The statistical models for PCA, K-mean cluster, and Pearson’s analysis revealed significant correlation (P ≤ 0.005) for origin*solvent*temperature Vs MG-amount with a nonsignificant correlation for origin*MG-amount Vs extract yield. The ASE-UPLC-MS/MS comprehensively characterized inter-, and intra-variation of MG in different parts of mango fruit.
Plants
This study evaluates the quality variation for twenty-seven capsicum fruit (CF) samples, in terms... more This study evaluates the quality variation for twenty-seven capsicum fruit (CF) samples, in terms of their volatile oil composition and biological activities. The GCMS analysis revealed the presence of seventy one chemical compounds from different chemical classes with an average (%) composition of: 26.13 (alcohols) > 18.82 (hydrocarbons) > 14.97 (esters) > 3.08 (ketones) > 1.14 (others) > 1.07 (acids) > 0.72 (sugar) > 0.42 (aldehydes) > 0.15 (amino compounds). Alcohols and hydrocarbons were the most abundant in these CF samples with 1-Decanol, 2-octyl- and docosanoic acid, docosyl ester as the major components, respectively. The % inhibition in cytotoxicity assays was observed in the range of 9–47 (MCF7) and 4–41 (HCT116) whereas, the zone of inhibition (mm) for the antimicrobial activity was found to be 0.0–17 (P. aeruginosa) > 0.0–13 (E. coli and S. aureus). Moreover, the samples with the largest zone of inhibition in the agar-well-diffusion method (C16...
Angewandte Chemie
By limiting the nitrogen source to glutamic acid, we isolated cyclic peptides from Euglena gracil... more By limiting the nitrogen source to glutamic acid, we isolated cyclic peptides from Euglena gracilis containing asparagine and non-proteinogenic amino acids. Structure elucidation was accomplished through spectroscopic methods, mass spectrometry and chemical degradation. The euglenatides potently inhibit pathogenic fungi and cancer cell lines e.g., euglenatide B exhibiting IC50 values of 4.3 M in ketoconazole resistant Aspergillus fumigatus and 0.29 M in MCF-7 breast cancer cells. In an unprecedented convergence of non-ribosomal peptide synthetase and polyketide synthase assembly-line biosynthesis between unicellular species and the metazoan kingdom, euglenatides bear resemblance to nemamides from Caenorhabditis elegans and inhibited both producing organisms E. gracilis and C. elegans. By molecular network analysis, we detected over forty euglenatide-like metabolites in E. gracilis, E. sanguinea and E. mutabilis, suggesting an important biological role for these natural products.
Food Additives & Contaminants: Part B, 2022
The journal of APJCP (Asian Pacific Journal of Cancer Prevention) focuses to gather relevant and ... more The journal of APJCP (Asian Pacific Journal of Cancer Prevention) focuses to gather relevant and up-to-date novel information's related to cancer sciences. The research methodologies and approaches adopted by the researcher are prone to variation which may be desirable in the context of novel scientific findings however, the reproducibility for these studies needs to be unified and assured. The reproducibility issues are highly concerned when preclinical studies are reported in cancer, for natural products in particular. The natural products and medicinal plants are prone to a wide variation in terms of phytochemistry and phyto-pharmacology, ultimately affecting the end results for cancer studies. Hence the need for specific guidelines to adopt a best-practice in cancer research are utmost essential. The current AIMRDA guidelines aims to develop a consensus-based tool in order to enhance the quality and assure the reproducibility of studies reporting natural products in cancer prevention. A core working committee of the experts developed an initial draft for the guidelines where more focus was kept for the inclusion of specific items not covered in previous published tools. The initial draft was peer-reviewed, experts-views provided, and improved by a scientific committee comprising of field research experts, editorial experts of different journals, and academics working in different organization worldwide. The feedback from continuous online meetings, mail communications, and webinars resulted a final draft in the shape of a checklist tool, covering the best practices related to the field of natural products research in cancer prevention and treatment. It is mandatory for the authors to read and follow the AIMRDA tool, and be aware of the good-practices to be followed in cancer research prior to any submission to APJCP. Though the tool is developed based on experts in the field, it needs to be further updated and validated in practice via implementation in the field.
Microbial natural products represent a significant portion of small-molecule drugs approved for c... more Microbial natural products represent a significant portion of small-molecule drugs approved for clinical use, especially as anti-infective and anticancer agents. Nevertheless, most clinically used anti-infective and anticancer agents suffer from resistance and other drawbacks such as adverse effects, drug interactions and poor pharmacokinetic properties. Some of the main challenges in the natural product discovery field are the high rediscovery rates and low yield of natural products. One of the factors contributing to this problem is the fact that the genes responsible for the production of a great number of natural products are transcriptionally inactive (silent) or poorly expressed under laboratory conditions, resulting in undetectable concentrations of the corresponding products. Therefore, this project aimed at activating natural product genes in Euglena microalgae, Aspergillus fungi and actinomycete bacteria through nutritional and epigenetic manipulation. Nutritional manipula...
A novel, green and eco-friendly, cost-effective, fast, and reliable high energy ultrasonication (... more A novel, green and eco-friendly, cost-effective, fast, and reliable high energy ultrasonication (US) extraction with UHPLC-MSMS quantification of Glycyrrhizic acid (GZA) is reported herein for the first time. The study provides useful insights regarding the effect of US-factors with statistical analysis and mechanisms, involved in GZA-extraction and analysis. An US-extraction method (US-MD) was developed using three levels of US factors: solvent (AC (acetone), EtOH (ethanol), H2O (water)), time (1, 2, 3 min), amplitude (30, 40, 50%), pulse (10/0.5, 20/0.5, 30/0.5 sec), particle size (0.5, 1, 1.4 mm), and temperature (20, 30, 40 °C). The US-MD was further validated (US-MV) with high accuracy 98.96 ±6.82 and r2=0.995 whereas, an in-house analytical method (UHPLC-MSMS) was developed and validated to quantify the GZAamount. UHPLCMSMS-MD resulted in a retention time of 0.31 min with MSMS (821.400>351.200) in a 1 min run time whereas, UHPLCMSMS-MV showed high accuracy and precision wit...
Ultrasonics Sonochemistry
Highlights • Green and novel US-extraction and UHPLC-MSMS analysis method was developed/validated... more Highlights • Green and novel US-extraction and UHPLC-MSMS analysis method was developed/validated.• Temperatures, solvents, amplitudes, pulse rates, and particle sizes were correlated with GZA.• Cavitation, turbulence, sonocapillary, and sonochemical effects were observedduring US-process.• A linear increase was observed with an increase in US-factors with an exception of particle size.• Solvent showed more correlation with GZA whereas, particle size more towards extract yield.
In this review, we discuss novel natural products discovered within the last decade that are repo... more In this review, we discuss novel natural products discovered within the last decade that are reported to have antifungal activity against pathogenic species. Nearly a hundred natural products were identified that originate from bacteria, alga, fungi, sponges and plants. Fungi were the most prolific source of antifungal compounds discovered during the period of review. The structural diversity of these antifungal leads encompasses all the major classes of natural products including polyketides, shikimate metabolites, terpenoids, alkaloids and peptides.
The Journal of Antibiotics