A5103028661- Synthetic Organic Chemistry Methods
- Asymmetric Synthesis and Catalysis
- Traditional and Medicinal Uses of Annonaceae
- Plant-derived Lignans Synthesis and Bioactivity
- Insect Pest Control Strategies
- Microbial Natural Products and Biosynthesis
- Phytochemical compounds biological activities
- Chemical synthesis and alkaloids
- Marine Sponges and Natural Products
- Plant biochemistry and biosynthesis
- T-cell and Retrovirus Studies
- Biological Activity of Diterpenoids and Biflavonoids
- Oxidative Organic Chemistry Reactions
- Allelopathy and phytotoxic interactions
- Cholinesterase and Neurodegenerative Diseases
- Phytochemistry and Biological Activities
- Chemical Synthesis and Analysis
- Natural product bioactivities and synthesis
- Analytical Chemistry and Chromatography
- Olfactory and Sensory Function Studies
- NF-κB Signaling Pathways
- Biotin and Related Studies
- Sesame and Sesamin Research
- Insect and Pesticide Research
- Genomics, phytochemicals, and oxidative stress
Tohoku University
1997-2025
Rigaku (Japan)
2025
The University of Tokyo
2010-2024
University of the Ryukyus
2001-2024
Research Foundation ITSUU Laboratory
2020
Bunkyo University
2006-2016
Nagasaki University
2001-2011
Kanazawa University
2011
Teikyo University
2006
Uniformed Services University of the Health Sciences
2001
The asymmetric aldol reaction of ethyl trifluoropyruvate with aldehydes was developed using diarylprolinol as a catalyst, affording α‐trifluoromethyl‐substituted tertiary alcohols high enantioselectivity. Similarly, the Mannich an imine derived from diphenylprolinol silyl ether in combination acid, yielding amines. absolute and relative configurations products were determined by vibrational circular dichroism (VCD).
The diterpene cyclase CotB2 catalyzes the cyclization of geranylgeranyl diphosphate (GGPP) to tricyclic cyclooctat-9-en-7-ol, which is characterized by a 5-8-5-fused ring skeleton. We have previously proposed cascade involving unique carbon–carbon bond rearrangement combined with multiple hydride shifts, all occurring at single active site. Here, we report first high-resolution X-ray crystal structure bound substrate analog thiodiphosphate (GGSPP). In GGSPP-bound form, GGSPP folds into...
From A to B: The decalin moiety of azadirachtin, which includes the fully functionalized AB ring system (see picture), was synthesized stereoselectively in only 23 steps. Key steps include an intramolecular Diels–Alder reaction, a decarboxylation, Claisen rearrangement, and finally tandem radical cyclization.
Abstract An asymmetric formal synthesis of azadirachtin, a potent insect antifeedant, was accomplished in 30 steps to Ley’s synthetic intermediate (longest linear sequence). The features: 1) rapid access the optically active right‐hand segment starting from known 5‐hydroxymethyl‐2‐cyclopentenone scaffold; 2) construction B and E rings by key intramolecular tandem radical cyclization; 3) formation hemiacetal moiety C ring through α‐oxidation six‐membered lactone followed methanolysis.
Chamobtusin A, a unique diterpene alkaloid isolated from Chamaecyparis obtusa cv. tetragon, is considered to be biosynthesized an abietane diterpenoid. On the basis of this biosynthetic hypothesis, ferruginol (15) was synthesized (+)-dehydroabietylamine and then biomimetically transformed into (-)-chamobtusin A in 6 steps (12 (+)-dehydroabietylamine).
A three-pot asymmetric synthesis of the anti-1,3-diol unit was developed. In first pot, enantioselective aldol reaction aldehydes proceeds, catalyzed by organocatalyst, followed either Wittig or Horner-Wadsworth-Emmons reactions to afford δ-hydroxy α,β-unsaturated carbonyls with excellent enantioselectivity. Diastereoselective hydroxy-directed anti-epoxidation proceeds in next pot use tert-BuOOH and LiHMDS. Reductive opening epoxide a third anti-β,δ-hydroxy carbonyl compounds diastereo-
A total synthesis of (±)-chamobtusin has been accomplished on the basis our presumed biosynthetic pathway: imine formation keto aldehyde followed by intramolecular aza-Michael addition.
An enantioselective total synthesis of (+)-anthecularin, an antiplasmodial and antitrypanosomal sesquiterpene lactone, has been achieved in 3.9% overall yield through 18 steps from a known dibromo alcohol. The key features the include intramolecular Claisen-type cyclization formyl-protected hydroxyl lactone to construct bicyclic intermediate with quaternary stereogenic center stereocontrolled 1,2-addition vinyllithium methoxyethyl-protected spirocyclic enone install tetrasubstituted...
Cyclooxygenase-2 (COX-2), an inducible enzyme that catalyzes the formation of prostaglandins and other eicosanoids from arachidonic acid, is constitutively expressed in several human carcinomas. COX-2 expression, however, has not been extensively studied leukemia. Human T cell leukemia virus type I (HTLV-I) etiologic agent adult leukemia, aggressive form malignancy. We mRNA expression various T-cell lines. Northern blot analysis revealed steady-state levels were high 4 7 lines infected with...
Von A nach B: Die Decalineinheit von Azadirachtin, die das vollständig funktionalisierte AB-Ringsystem umfasst (siehe Bild), wurde stereoselektiv in nur 23 Stufen synthetisiert. Schlüsselschritte sind eine intramolekulare Diels-Alder-Reaktion, Decarboxylierung, Claisen-Umlagerung und schließlich Tandem-Radikalcyclisierung.