A5071110237- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Asymmetric Synthesis and Catalysis
- Synthetic Organic Chemistry Methods
- Asymmetric Hydrogenation and Catalysis
- Chemical Synthesis and Analysis
- Oxidative Organic Chemistry Reactions
- Ubiquitin and proteasome pathways
- Synthesis of Indole Derivatives
- Chemical synthesis and alkaloids
- Catalytic Cross-Coupling Reactions
- Catalytic C–H Functionalization Methods
- Click Chemistry and Applications
- Crystallography and molecular interactions
- Plant biochemistry and biosynthesis
- Tuberculosis Research and Epidemiology
- Microbial Natural Products and Biosynthesis
- Catalysis and Oxidation Reactions
- Chemical and Physical Properties in Aqueous Solutions
- 14-3-3 protein interactions
- Synthesis and Biological Activity
- Traditional and Medicinal Uses of Annonaceae
- Organoboron and organosilicon chemistry
- Biotin and Related Studies
- Toxoplasma gondii Research Studies
University of Minnesota
2020-2024
Virginia Commonwealth University
2022-2023
Indian Institute of Science Education and Research, Bhopal
2015-2018
University of Kalyani
1980
ABSTRACT In the apicomplexans, endocytosed cargos (e.g., hemoglobin) are trafficked to a specialized organelle for digestion. This follows unique endocytotic process at micropore/cytostome in these parasites. However, mechanism underlying endocytic trafficking remains elusive, due repurposing of classical proteins biogenesis apical organelles. To resolve this issue, we have exploited genetic tractability model apicomplexan Toxoplasma gondii , which ingests host cytosolic materials green...
Abstract An unprecedented enantioselective peroxyhemiacetalization/oxa‐Michael addition cascade of ortho ‐formyl homochalcones has been developed using cinchona‐alkaloid‐based chiral bifunctional organocatalysts to provide cis ‐configured exo ‐peroxyacetals, a new class organic peroxide, in good yields with excellent enantio‐ and diastereoselectivities. The resulting ‐peroxyacetals were converted into the corresponding trans peroxyacetals without affecting enantioselectivity. Furthermore,...
The enantioselective oxa-Michael reaction of alkoxyboronate strategy was demonstrated to provide a new and practical route enantioriched 1- 3-substituted isochromans using chiral bifunctional organocatalyst. Furthermore, this methodology extended the synthesis (+)-sonepiprazole, dopamine receptor antagonist.
An enantioselective synthesis of 3-substituted benzoxaboroles has been developed using organocatalysts with good to excellent enantioselectivities (up 99%). The resulting were converted the chiral β-hydroxy ketones without affecting enantioselectivity.
Disclosed herein an overall methodology constitutes equivalent to the long sought after enantioselective intramolecular oxa-Michael (IOM) reaction of carboxylic acids. An organocatalyzed IOM in situ formed peroxy hemiacetals followed by a Kornblum DeLaMare type rearrangement cascade provides broad class chiral lactones good yields and with excellent enatioselectvities. Remarkably, pure are obtained without any silica gel column chromatography, many cases, enantioselectivity is further...
A unified dynamic kinetic spiroketalization/enantioselective oxa-Michael addition cascade of an aromatic ketone tethered to alkoxyboronate and enone moiety has been developed using cinchona alkaloid based amino-thiourea/squaramide organocatalysts provide isobenzofuran-based benzannulated spiroketals with high diastereoselectivities excellent enantioselectivities. Further, a peroxy-hemiacetalization/dynamic the above substrates provides corresponding exo-peroxy-benzannulated outstanding...
Abstract An unprecedented approach for the synthesis of homo‐ and hetero‐1,2,4‐triaryl benzenes has been developed using a simple base‐mediated reaction either α‐aryl cinnamyl alcohols or α,γ‐di‐aryl propanones. The salient feature this strategy involves sequential hydride transfer, regiospecific condensation, dearylation, aromatization under metal‐free conditions. unsymmetrically substituted triphenylenes by oxidative coupling synthesized 1,2,4‐triaryl also demonstrated.
Dysregulation of protein prenylation has been implicated in many diseases, including Alzheimer's disease (AD). Prenylomic analysis, the combination metabolic incorporation an isoprenoid analogue (C15AlkOPP) into prenylated proteins with a bottom-up proteomic allowed identification various cellular models. Here, transgenic AD mice were administered C15AlkOPP through intracerebroventricular (ICV) infusion over 13 days. Using prenylomic 36 enriched brains mice. Importantly, forms 15...
Chemoselective 1,2- and 1,4-addition of malononitriles to ortho-formyl chalcones using cinchona alkaloid based bifunctional chiral organocatalysts has been shown by tuning the electronic nature malononitriles. Alkyl (hard) undergo an asymmetric 1,2-addition followed oxa-Michael reaction cascade afford 1,3-disubstituted isobenzofurans with high enantio- diastereoselectivity. Aryl (soft) proceed through aldol provide indanols, having three consecutive stereocenters, in good yields excellent...
An enantioselective synthesis of Rauhut–Currier (RC) adducts from 3-aryl cyclohexenone with a tethered enone moiety at the ortho-position on aryl group is accomplished. This method provides wide range valuable synthetic building blocks having unique [6–5–6] all-carbon-fused tricyclic skeleton. A primary amine-containing thiourea, bifunctional organocatalyst, was found to be an efficient catalyst for this transformation. The amine counterpart possibly activates aliphatic via dienamine...
Bedaquiline (BDQ) is an important drug for treating multidrug-resistant tuberculosis (MDR-TB), a worldwide disease that causes more than 1.6 million deaths yearly. The current synthetic strategy adopted by the manufacturers to assemble this molecule relies on nucleophilic addition reaction of quinoline fragment ketone, but it suffers from low conversion and no stereoselectivity, which subsequently increases cost manufacturing BDQ. Medicines All Institute (M4ALL) has developed new methodology...
Abstract An unprecedented enantioselective peroxyhemiacetalization/oxa‐Michael addition cascade of ortho ‐formyl homochalcones has been developed using cinchona‐alkaloid‐based chiral bifunctional organocatalysts to provide cis ‐configured exo ‐peroxyacetals, a new class organic peroxide, in good yields with excellent enantio‐ and diastereoselectivities. The resulting ‐peroxyacetals were converted into the corresponding trans peroxyacetals without affecting enantioselectivity. Furthermore,...
Abstract An unprecedented approach for the synthesis of homo‐ and hetero‐1,2,4‐triaryl benzenes has been developed using a simple base‐mediated reaction either α‐aryl cinnamyl alcohols or α,γ‐di‐aryl propanones. The salient feature this strategy involves sequential hydride transfer, regiospecific condensation, dearylation, aromatization under metal‐free conditions. unsymmetrically substituted triphenylenes by oxidative coupling synthesized 1,2,4‐triaryl also demonstrated.
Bedaquiline is a crucial medicine in the global fight against tuberculosis, yet its high price places it out of reach for many patients. Herein, we describe improvements to key industrial lithiation-addition sequence that enable higher yielding and therefore more economical synthesis bedaquiline. Prioritization mechanistic understanding multi-lab reproducibility led optimized reaction conditions feature an unusual base-salt pairing afford doubling yield racemic We anticipate implementation...
Bedaquiline (BDQ) is an important drug for treating multidrug-resistant tuberculosis (MDR-TB), a worldwide disease that causes more than 1.6 million deaths yearly. The current synthetic strategy adopted by the manufacturers to assemble this molecule relies on nucleophilic addition reaction of two complex starting materials, but suffers from low conversion and no stereoselectivity, which subsequently increases cost manufacturing BDQ. M4ALL has developed new approach process not only allows...
Abstract Dysregulation of protein prenylation has been implicated in many diseases, including Alzheimer’s disease (AD). Prenylomic analysis, the combination metabolic incorporation an isoprenoid analogue (C15AlkOPP) into prenylated proteins with a bottom-up proteomic allowed identification various cellular models. Here, transgenic AD mice were administered C15AlkOPP through intracerebroventricular (ICV) infusion over 13 days. Using prenylomic 36 enriched brains mice. Importantly, forms 15...
Abstract Protein prenylation is one example of a broad class post-translational modifications where proteins are covalently linked to various hydrophobic moieties. To globally identify and monitor levels all prenylated in cell simultaneously, our laboratory others have developed chemical proteomic approaches that rely on the metabolic incorporation isoprenoid analogues bearing bio-orthogonal functionality followed by enrichment subsequent quantitative analysis. Here, several improvements...
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Prenylation consists of the modification proteins with either farnesyl diphosphate (FPP) or geranylgeranyl (GGPP) at a cysteine near C-terminus target to generate thioether-linked lipidated proteins. In recent work, metabolic labeling alkyne-containing isoprenoid analogues including C15AlkOPP has been used identify prenylated and track their levels in different diseases. Here, systematic study impact length on labeled these probes was performed. Chemical synthesis two new analogues,...
Abstract An unprecedented approach for the synthesis of homo‐ and heterotriaryl benzenes is developed by using a base‐mediated reaction either α‐aryl cinnamyl alcohols or α,γ‐diaryl propanones.