Shyam Yadav - Academia.edu (original) (raw)

Papers by Shyam Yadav

Tetrahedron-asymmetry, Oct 1, 2016

4-Hydroxy-2-methylproline diastereomers are successfully prepared without the use of an external ... more 4-Hydroxy-2-methylproline diastereomers are successfully prepared without the use of an external chiral auxiliary. Dihydroxylation of the key intermediate 2 resulted in lactone 4 as a mixture of diastereomers in good yield. Mesylation, hydrogenation and concomitant intramolecular cyclization of 4 led to the formation of both (2R,4R)-and (2R,4S)-4-hydroxy-2-methylprolines as a mixture of diastereomers. Appropriate protection followed by chromatographic separation resulted in isolation of both cis-and trans-diastereomers in enantiomerically pure form and in equal quantity. In subsequent experiments, the synthesis of the more challenging diastereomers (2R,4R)-and (2S,4S)-4-hydroxy-2-methylproline was achieved by diastereoselective iodolactonization of (R)-or (S)-allylalanine obtained after hydrolysis of intermediate 2, followed by pyrrolidine ring closer under mild alkaline conditions. After selective protection and deprotection, Fmoc-(2R,4R)-a-Me-Hyp(t Bu)-OH 14, a building block suitable for solid phase peptide synthesis was obtained.

Biomedical and biotechnology research journal, 2021

Background: Nanoparticles modulate several physiochemical and biological properties. In this rega... more Background: Nanoparticles modulate several physiochemical and biological properties. In this regard, silver nanoparticles (AgNPs) have shown remarkable applications. The present research work comprises green synthesis of AgNPs using aqueous leaves extract of Eranthemum pulchellum and evaluation of its efficacy as antifungal and antioxidant agents. Methods: Synthesized AgNPs have been characterized by Fourier Transforms Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet-visible spectrophotometry. Qualitative phytochemical analysis of aqueous leaves extract of E. pulchellum and FTIR spectrum of the synthesized AgNPs suggest about the presence of different phytochemicals and functional groups, respectively, which are responsible for reducing silver ions as well as capping and stabilizing synthesized nanoparticles. Results: The wavelength of maximum absorbance of AgNPs solution near to 439 nm indicates the spherical morphology. XRD infers about average crystalline size of the synthesized AgNPs to be ~12 nm. Selected area electron diffraction pattern of the synthesized AgNPs shows four visible diffraction rings corresponding to (111), (200), (220), and (311) set of planes which are attributed to face centered cubic metallic silver. The size and spherical shape of the synthesized AgNPs have been further determined by TEM. The synthesized AgNPs have shown a significant antifungal activity against Aspergillus flavus (AF-LHP-NS7) strain with minimum inhibitory concentration value of 200 μg/mL. The synthesized AgNPs have also shown strong antioxidant efficacy through Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid assay with IC50 value of 462.56 μg/mL. Conclusions: The present study shows a green and facile synthesis of AgNPs. Leaves extract of E. pulchellum has been first time utilized as efficient reductant for the AgNPs synthesis. These AgNPs have shown potent antifungal and antioxidant activity.

Global journal of computer science and technology, Sep 7, 2011

Biometric technologies are automated methods for measuring and analyzing biological data, extract... more Biometric technologies are automated methods for measuring and analyzing biological data, extracting a feature set from acquired data and comparing this set against to the templates set in the database. Unimodal biometric system have variety of problems such as noisy data, spool attacks etc. Multimodal biometrics refers the combination of two or more biometric modalities in a single identification. Most biometric verification systems are done based on knowledge base and token based identification these are prone to fraud. Biometric authentication employs unique combinations of measurable physical characteristics-fingerprint, facial features , iris of the eye, voice print and so on-that cannot be readily imitated or forged by others. This paper discuss the various scenarios that are possible in multi model biometric system , the level of fusion that are plausible and the integration strategic that can be adopted to consolidate information. Fusion methods include processing biometric madalitics sequential until an acceptable match is obtained.

ChemistrySelect, 2022

In this work copper oxide nanoparticles (CuONPs) are prepared from precursor CuSO4.5H2O using pla... more In this work copper oxide nanoparticles (CuONPs) are prepared from precursor CuSO4.5H2O using plant leaves extract (PEE) of Eranthemum pulchellum(E. pulchellum).The synthesized CuONPs are characterized by ultraviolet visible (UV‐vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD) and transmission electron microscopy (TEM). CuONPs are distorted spherical in shape, with the sizes ranging from 5 to 17 nm. PEE and CuONPs are coated on glassy carbon (GC) electrode and abbreviated as GC/PEE and GC/CuONPs, respectively. The modified electrodes GC/PEE and GC/CuONPs are characterized with cyclic voltammetry (CV) techniques. The modified electrode GC/CuONPs exhibits good electrocatalytic activity for oxygen reduction reaction (ORR). GC/CuONPs also shows excellent operational stability up to 1000 CV cycles.

Chirality, 2015

A simple and stereoselective synthesis of 3-methylthalidomide, a configurationally stable thalido... more A simple and stereoselective synthesis of 3-methylthalidomide, a configurationally stable thalidomide analog, is presented. Herein we describe the synthesis of (R)-3-methylthalidomide starting from (S)-alanine by piperidin-2-one ring assembly approach in high yield and enantiomeric purity without using a chiral auxiliary or reagent. Starting from (R)-alanine, the corresponding (S)-3-methylthalidomide can be prepared using the same methodology.

Biomedical and Biotechnology Research Journal (BBRJ), 2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a virus with single positive-stra... more Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a virus with single positive-strand RNA, having glycoproteins projection on envelopes so reveals a halo-like appearance or corona. Coronavirus is of four types: (1) α-coronavirus (α-COV); (2) β-coronavirus (β-COV); (3) δ-coronavirus (δ-COV); and (4) γ-coronavirus (γ-COV) and belongs to family Coronaviridae and subfamily Coronavirinae. Coronaviruses are the normal pathogens that cause broad band of gastrointestinal and respiratory diseases in domestic as well as wild animals such as pigs, birds, and rodents. Coronavirus is highly infectious in case of elders for mortality rate. The elder peoples are at 2-fold higher risk as compared to the younger population and the greater part of the population dying from coronavirus disease (COVID-19) is male. The virus enters into the body by the mouth, eyes, or nose, then particles march inside of the body by different pathways and affect vital organs in severe ways such as liver, heart muscle, blood vessels, kidneys, central nervous system, etc. Right now, the only solution to avoid COVID-19 infection is “precautions.” Different companies of different countries at different steps are in race to develop effective medicines for treatment and management of the same. Here, in this review, we tried to give an overview of all about SARS-CoV-2, COVID-19 infection, pathophysiology, mechanisms, and various treatment trials.

Climate Change and Management of Cool Season Grain Legume Crops, 2010

Page 1. Chapter 5 Consequences of Predicted Climatic Changes on International Trade in Cool Seaso... more Page 1. Chapter 5 Consequences of Predicted Climatic Changes on International Trade in Cool Season Grain Legume Crops Mitchell Andrews, Hamid Seddighi, Simon Hodge, Bruce A. McKenzie, and Shyam S. Yadav 5.1 Introduction ...

Climate Change and Management of Cool Season Grain Legume Crops, 2010

Page 1. Chapter 21 Strategies to Combat the Impact of Climatic Changes Shyam S. Yadav, Bob Redden... more Page 1. Chapter 21 Strategies to Combat the Impact of Climatic Changes Shyam S. Yadav, Bob Redden, David L. McNeil, Yantai Gan, Aqeel Rizvi, AK Vrema, and PN Bahl 21.1 Introduction The most important global debate of this century is on climate change. ...

Climate Change and Management of Cool Season Grain Legume Crops, 2010

Archives of Agronomy and Soil Science, 2010

Tetrahedron-asymmetry, Oct 1, 2016

4-Hydroxy-2-methylproline diastereomers are successfully prepared without the use of an external ... more 4-Hydroxy-2-methylproline diastereomers are successfully prepared without the use of an external chiral auxiliary. Dihydroxylation of the key intermediate 2 resulted in lactone 4 as a mixture of diastereomers in good yield. Mesylation, hydrogenation and concomitant intramolecular cyclization of 4 led to the formation of both (2R,4R)-and (2R,4S)-4-hydroxy-2-methylprolines as a mixture of diastereomers. Appropriate protection followed by chromatographic separation resulted in isolation of both cis-and trans-diastereomers in enantiomerically pure form and in equal quantity. In subsequent experiments, the synthesis of the more challenging diastereomers (2R,4R)-and (2S,4S)-4-hydroxy-2-methylproline was achieved by diastereoselective iodolactonization of (R)-or (S)-allylalanine obtained after hydrolysis of intermediate 2, followed by pyrrolidine ring closer under mild alkaline conditions. After selective protection and deprotection, Fmoc-(2R,4R)-a-Me-Hyp(t Bu)-OH 14, a building block suitable for solid phase peptide synthesis was obtained.

Biomedical and biotechnology research journal, 2021

Background: Nanoparticles modulate several physiochemical and biological properties. In this rega... more Background: Nanoparticles modulate several physiochemical and biological properties. In this regard, silver nanoparticles (AgNPs) have shown remarkable applications. The present research work comprises green synthesis of AgNPs using aqueous leaves extract of Eranthemum pulchellum and evaluation of its efficacy as antifungal and antioxidant agents. Methods: Synthesized AgNPs have been characterized by Fourier Transforms Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet-visible spectrophotometry. Qualitative phytochemical analysis of aqueous leaves extract of E. pulchellum and FTIR spectrum of the synthesized AgNPs suggest about the presence of different phytochemicals and functional groups, respectively, which are responsible for reducing silver ions as well as capping and stabilizing synthesized nanoparticles. Results: The wavelength of maximum absorbance of AgNPs solution near to 439 nm indicates the spherical morphology. XRD infers about average crystalline size of the synthesized AgNPs to be ~12 nm. Selected area electron diffraction pattern of the synthesized AgNPs shows four visible diffraction rings corresponding to (111), (200), (220), and (311) set of planes which are attributed to face centered cubic metallic silver. The size and spherical shape of the synthesized AgNPs have been further determined by TEM. The synthesized AgNPs have shown a significant antifungal activity against Aspergillus flavus (AF-LHP-NS7) strain with minimum inhibitory concentration value of 200 μg/mL. The synthesized AgNPs have also shown strong antioxidant efficacy through Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid assay with IC50 value of 462.56 μg/mL. Conclusions: The present study shows a green and facile synthesis of AgNPs. Leaves extract of E. pulchellum has been first time utilized as efficient reductant for the AgNPs synthesis. These AgNPs have shown potent antifungal and antioxidant activity.

Global journal of computer science and technology, Sep 7, 2011

Biometric technologies are automated methods for measuring and analyzing biological data, extract... more Biometric technologies are automated methods for measuring and analyzing biological data, extracting a feature set from acquired data and comparing this set against to the templates set in the database. Unimodal biometric system have variety of problems such as noisy data, spool attacks etc. Multimodal biometrics refers the combination of two or more biometric modalities in a single identification. Most biometric verification systems are done based on knowledge base and token based identification these are prone to fraud. Biometric authentication employs unique combinations of measurable physical characteristics-fingerprint, facial features , iris of the eye, voice print and so on-that cannot be readily imitated or forged by others. This paper discuss the various scenarios that are possible in multi model biometric system , the level of fusion that are plausible and the integration strategic that can be adopted to consolidate information. Fusion methods include processing biometric madalitics sequential until an acceptable match is obtained.

ChemistrySelect, 2022

In this work copper oxide nanoparticles (CuONPs) are prepared from precursor CuSO4.5H2O using pla... more In this work copper oxide nanoparticles (CuONPs) are prepared from precursor CuSO4.5H2O using plant leaves extract (PEE) of Eranthemum pulchellum(E. pulchellum).The synthesized CuONPs are characterized by ultraviolet visible (UV‐vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD) and transmission electron microscopy (TEM). CuONPs are distorted spherical in shape, with the sizes ranging from 5 to 17 nm. PEE and CuONPs are coated on glassy carbon (GC) electrode and abbreviated as GC/PEE and GC/CuONPs, respectively. The modified electrodes GC/PEE and GC/CuONPs are characterized with cyclic voltammetry (CV) techniques. The modified electrode GC/CuONPs exhibits good electrocatalytic activity for oxygen reduction reaction (ORR). GC/CuONPs also shows excellent operational stability up to 1000 CV cycles.

Chirality, 2015

A simple and stereoselective synthesis of 3-methylthalidomide, a configurationally stable thalido... more A simple and stereoselective synthesis of 3-methylthalidomide, a configurationally stable thalidomide analog, is presented. Herein we describe the synthesis of (R)-3-methylthalidomide starting from (S)-alanine by piperidin-2-one ring assembly approach in high yield and enantiomeric purity without using a chiral auxiliary or reagent. Starting from (R)-alanine, the corresponding (S)-3-methylthalidomide can be prepared using the same methodology.

Biomedical and Biotechnology Research Journal (BBRJ), 2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a virus with single positive-stra... more Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a virus with single positive-strand RNA, having glycoproteins projection on envelopes so reveals a halo-like appearance or corona. Coronavirus is of four types: (1) α-coronavirus (α-COV); (2) β-coronavirus (β-COV); (3) δ-coronavirus (δ-COV); and (4) γ-coronavirus (γ-COV) and belongs to family Coronaviridae and subfamily Coronavirinae. Coronaviruses are the normal pathogens that cause broad band of gastrointestinal and respiratory diseases in domestic as well as wild animals such as pigs, birds, and rodents. Coronavirus is highly infectious in case of elders for mortality rate. The elder peoples are at 2-fold higher risk as compared to the younger population and the greater part of the population dying from coronavirus disease (COVID-19) is male. The virus enters into the body by the mouth, eyes, or nose, then particles march inside of the body by different pathways and affect vital organs in severe ways such as liver, heart muscle, blood vessels, kidneys, central nervous system, etc. Right now, the only solution to avoid COVID-19 infection is “precautions.” Different companies of different countries at different steps are in race to develop effective medicines for treatment and management of the same. Here, in this review, we tried to give an overview of all about SARS-CoV-2, COVID-19 infection, pathophysiology, mechanisms, and various treatment trials.

Climate Change and Management of Cool Season Grain Legume Crops, 2010

Page 1. Chapter 5 Consequences of Predicted Climatic Changes on International Trade in Cool Seaso... more Page 1. Chapter 5 Consequences of Predicted Climatic Changes on International Trade in Cool Season Grain Legume Crops Mitchell Andrews, Hamid Seddighi, Simon Hodge, Bruce A. McKenzie, and Shyam S. Yadav 5.1 Introduction ...

Climate Change and Management of Cool Season Grain Legume Crops, 2010

Page 1. Chapter 21 Strategies to Combat the Impact of Climatic Changes Shyam S. Yadav, Bob Redden... more Page 1. Chapter 21 Strategies to Combat the Impact of Climatic Changes Shyam S. Yadav, Bob Redden, David L. McNeil, Yantai Gan, Aqeel Rizvi, AK Vrema, and PN Bahl 21.1 Introduction The most important global debate of this century is on climate change. ...

Climate Change and Management of Cool Season Grain Legume Crops, 2010

Archives of Agronomy and Soil Science, 2010