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Pradeep B. Lasonkar

Bio: Pradeep B. Lasonkar is an academic researcher from National Chemical Laboratory. The author has contributed to research in topics: Duff reaction & Enantioselective synthesis. The author has an hindex of 6, co-authored 13 publications receiving 70 citations. Previous affiliations of Pradeep B. Lasonkar include Council of Scientific and Industrial Research & University of Mississippi.

Papers
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Journal ArticleDOI
TL;DR: Three candidate sensitizers were isolated from German chamomile based on activity‐guided fractionation of chammile extracts tested using the in vitro KeratinoSens™ assay, finding the polyacetylene tonghaosu to be unstable and categorized as potential pre‐hapten.

27 citations

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TL;DR: A total of 10 compounds were synthesized by altering the enantiomer of isopulegol and the substituted benzaldehyde, and the resulting enantiopure octahydrochromenes were screened in vitro against the cannabinoid receptor isoforms CB1 and CB2.

16 citations

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TL;DR: The presence of DMBA was confirmed using a reference standard and was not detected in any of 25 authentic or commercial samples of Camellia sinensis tea leaves (green tea, black tea, Oolong tea, and Pouchung tea).

11 citations

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TL;DR: The PPTS-catalyzed intramolecular diastereoselective Henry reaction to fix three contiguous stereocenters on tetrahydronaphthalene and the first-of-its-kind synthesis of the 3-azidopiperidine skeleton, using a CAN-mediated regioselectives azidoalkoxylation of enol ether, are important findings of the present work.

10 citations

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TL;DR: In this paper, a novel and enantioselective synthesis of d -(+)-biotin has been achieved starting from commercially available cyclohexanone using Sharpless asymmetric dihydroxylation of a (E )-ethyl 3-(2-chlorocyclohex-1-en-1yl)acrylate derivative.
Abstract: A novel and enantioselective synthesis of d -(+)-biotin has been accomplished starting from commercially available cyclohexanone. The key steps in the sequence are the Sharpless asymmetric dihydroxylation of a ( E )-ethyl 3-(2-chlorocyclohex-1-en-1-yl)acrylate derivative to establish the stereocenters of d -(+)-biotin, the carboxyalkyl side chain is introduced by unmasking the cyclohexene by ozonolysis and enzymatic hydrolysis of a thioacetate.

8 citations


Cited by
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TL;DR: A comprehensive overview of recent and key applications in the areas of compositional analysis, food authentication, quality control, and human nutrition is provided, and limitations, gaps, and potentials are discussed.
Abstract: Nuclear magnetic resonance (NMR) spectroscopy is a robust method, which can rapidly analyze mixtures at the molecular level without requiring separation and/or purification steps, making it ideal for applications in food science. Despite its increasing popularity among food scientists, NMR is still an underutilized methodology in this area, mainly due to its high cost, relatively low sensitivity, and the lack of NMR expertise by many food scientists. The aim of this review is to help bridge the knowledge gap that may exist when attempting to apply NMR methodologies to the field of food science. We begin by covering the basic principles required to apply NMR to the study of foods and nutrients. A description of the discipline of chemometrics is provided, as the combination of NMR with multivariate statistical analysis is a powerful approach for addressing modern challenges in food science. Furthermore, a comprehensive overview of recent and key applications in the areas of compositional analysis, food authentication, quality control, and human nutrition is provided. In addition to standard NMR techniques, more sophisticated NMR applications are also presented, although limitations, gaps, and potentials are discussed. We hope this review will help scientists gain some of the knowledge required to apply the powerful methodology of NMR to the rich and diverse field of food science.

183 citations

Journal ArticleDOI
TL;DR: Regulatory actions against manufacturers of products labelled as dietary supplements that contain the aliphatic amines 1,3-dimethylamine and 1,2-dimethylbutylamine, and PEAs such as β-methylphenethylamines, aegeline, and Dendrobium illustrate the FDA's use of its authority under the FD&C Act to promote dietary supplement safety.
Abstract: The multi-billion dollar dietary supplement industry is global in reach. The industry has been criticized for problems related to poor quality control, safety, misbranding, and adulteration. In this review, we describe how the US Food and Drug Administration (FDA) regulates dietary supplements within the framework of the Federal Food, Drug, and Cosmetic Act (FD&C Act). The Dietary Supplement Health and Education Act of 1994 (DSHEA), which amended the FD&C Act, gave the FDA the authority to promulgate Good Manufacturing Practices for dietary supplements and required that manufacturers provide the FDA information supporting a conclusion that the ingredients are reasonably expected to be safe if the dietary ingredients were not marketed in the USA before 15 October 1994. Recent amendments to the FD&C Act require that serious dietary-supplement-related adverse events be reported to the FDA and provide the agency with mandatory recall authority. We discuss the presence of naturally occurring (e.g. Ephedra, Citrus aurantium, Acacia) and synthetic (e.g. β-methylphenethylamines, methylsynephrine, α-ethyl-phenethylamine) biologically active phenethylamines (PEAs) in dietary supplements and of PEA drugs (e.g. clenbuterol, fenfluramine, sibutramine, lorcaserin) in weight-loss products. Regulatory actions against manufacturers of products labelled as dietary supplements that contain the aliphatic amines 1,3-dimethylamine and 1,3-dimethylbutylamine, and PEAs such as β-methylphenethylamine, aegeline, and Dendrobium illustrate the FDA's use of its authority under the FD&C Act to promote dietary supplement safety. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

75 citations

Journal ArticleDOI
TL;DR: Trifluoroacetic acid (TFA) has been widely used in organic synthesis as a solvent, catalyst and reagent as discussed by the authors, including rearrangements, functional group deprotections, oxidations, reductions, condensations, hydroarylations and trifluoromethylations.

63 citations

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TL;DR: The transition-metal-free coupling of esters with geminal bis(boron) compounds forms an α,α-bis(enolate) equivalent which can be trapped with electrophiles including alkyl halides and fluorinating agents and presents an efficient, convergent synthetic strategy for the synthesis of unsymmetrical blocked ketones.
Abstract: Regioselective α,α-difunctionalization adjacent to a ketone is a significant synthetic challenge Here, we present a solution to this problem through the transition-metal-free coupling of esters with geminal bis(boron) compounds This forms an α,α-bis(enolate) equivalent which can be trapped with electrophiles including alkyl halides and fluorinating agents This presents an efficient, convergent synthetic strategy for the synthesis of unsymmetrical blocked ketones

55 citations

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TL;DR: Applications of the methodology in the concise synthesis of RO 20-1724 as well as in the formal total syntheses of both (±)-hamacanthin B and (±-quinagolide further demonstrate the broad synthetic potential of this highly functional-group-tolerant reaction.
Abstract: Unprotected, primary 2-azidoamines are versatile precursors to vicinal diamines, which are among the most common motifs in biologically active compounds. Herein, we report their operationally simpl...

53 citations