A5073408022- Chemical synthesis and alkaloids
- Synthetic Organic Chemistry Methods
- Chemical Synthesis and Analysis
- Asymmetric Synthesis and Catalysis
- Traditional and Medicinal Uses of Annonaceae
- Plant chemical constituents analysis
- Synthesis and Catalytic Reactions
- Oxidative Organic Chemistry Reactions
- Synthesis of Organic Compounds
- Synthesis and Biological Evaluation
- Synthesis and Biological Activity
- Carbohydrate Chemistry and Synthesis
- Alkaloids: synthesis and pharmacology
- Synthesis and Reactions of Organic Compounds
- Microbial Natural Products and Biosynthesis
- Bioactive Compounds and Antitumor Agents
- Berberine and alkaloids research
- Analytical Chemistry and Chromatography
- Natural product bioactivities and synthesis
- Gastric Cancer Management and Outcomes
- Phytochemical compounds biological activities
- Chemical Synthesis and Reactions
- Amino Acid Enzymes and Metabolism
- Catalytic C–H Functionalization Methods
- Phytochemistry and Biological Activities
Yamagata University
2023
Waseda University
2023
Nippon Soken (Japan)
2023
The Graduate University for Advanced Studies, SOKENDAI
2023
Nagoya University
2023
Kyushu University
1999-2023
Toneyama National Hospital
2023
Institute of Particle and Nuclear Studies
2023
High Energy Accelerator Research Organization
2023
RIKEN
2023
Guanidine is categorized as an organic superbase, yet its synthetic application immature despite wide potential utility. The role of guanidine in synthesis, including asymmetric reactions, discussed herein.
Investigations on modified guanidines, prepared by newly developed methods, as potential chiral auxiliaries led to reasonable asymmetric induction not only in catalytic but also stoichiometric syntheses. These guanidine-mediated reactions may contribute the development of green chemistry because their possible application re-cyclable (economically favored) and easily functionalizable (widely applicable) auxiliaries.
Abstract Background and Aim: Colonic perforation is the serious accidental complication. The aim of this study to analyze clinical presentation management recent iatrogenic perforations during therapeutic colonoscopy. Methods: Consecutive patients referred four academic cancer centers in Japan were retrospectively reviewed using each center's endoscopy database medical records. Data was obtained by means an extensive data collection sheet. Since we evaluated including newly developed...
Modified guanidines could effectively mediate asymmetric silylation of secondary alcohols as recyclable bases under simple and mild conditions.
Modified guanidines efficiently catalysed the asymmetric Michael reaction of a prochiral glycine derivative with acrylate or its related compounds either in solution without solvent under simple and mild conditions (>95% ee).
See also: Commentaire de travail N. Kobayashi et al., pp. 701Endoscopy 2007; 39(08): 844-845DOI: 10.1055/s-0032-1308857
2-Chloro-1,3-dimethylimidazolinium chloride (DMC) (3) can act as a powerful dehydrating agent, replacing DCC (1) under nearly neutral conditions. Its application to acylation and dehydration is described.
Miroestrol (1) has been isolated previously as an active principle from "Kwao Keur" (Pueraria mirifica), a rejuvenating folk medicine Thailand. Reinvestigation using bioassay-guided purification resulted in the isolation of new potent phytoestrogen, deoxymiroestrol (2). The facile aerial oxidation 2 into 1 suggests possibility that may be artifact.
We report 92 patients treated with esophagectomy for superficial esophageal carcinoma (SEC; 9.1% of all resected cancers at our institution). the operative mortality rate was 5.4%. in 24 cases, cancer invasion limited to mucosa, and 68 submucosa. Twenty-three former group had no lymph node involvement, whereas (35.3%) latter metastases. 5-year survival after surgery SEC mucosa 83.5%, which significantly better than that invading submucosa (54.9%). No recurrent disease occurred lesions...
For large colorectal tumors, the en bloc resection rate achieved by endoscopic mucosal (EMR) is insufficient, and this leads to a high of local recurrence. As submucosal dissection (ESD) has been reported achieve higher lower recurrence in short-term, it expected overcome limitations EMR. We conducted matched case-control study between ESD EMR clarify effectiveness for tumors.Between April 2005 February 2009, total 28 tumors patients were resected followed up colonoscopy at least once....
Three new cyclobutanoid amides with trans-trans-trans configurations, piperarborenine C, D and E, a furanoid lignan, (+)-arborone, together twelve known compounds, were isolated from the stems of Piper arborescens. The structures these compounds determined by means spectral analyses. Piperarborenine (+)-diayangambin, piplartine, piperolactam B, aristolactam BIII, goniothalactam, methyl trans-3,4,5-trimethoxycinnamate possessed anti-platelet aggregation activity in vitro. Among them,...
(−)-Quinine-catalyzed intramolecular oxo-Michael addition (IMA) of 7-hydroxy-5-methoxy-8-tigloylcoumarins was developed for the enantioselective construction 2,3-dimethyl-4-chromanone systems in context asymmetric synthesis anti-HIV-1 active Calophyllum coumarins. Combination IMA and MgI2-assisted demethylation 5-methoxy group along with isomerization formed chromanone as key steps successfully led to concise (+)-inophyllum B (+)-calanolide A, possible candidates AIDS drugs. Further...
2-Chloro-1,3-dimethylimidazolinium chloride (DMC) (1) can act as a powerful dehydrating equivalent to DCC (2) under nearly neutral conditions. Its application the construction of heterocycles through dehydration reactions is described.
Abstract Of 393 patients with squamous‐cell carcinoma in the thoracic esophagus, 60 were found by histologic examination to have intramural metastasis. Metastases 50 of these identified gross inspection. There appeared be no preference for location proximal primary lesion. Eighteen had metastasis gastric wall, which suggested existence communicating lymphatic channels between wall esophagus and stomach. All tumors invaded beyond submucosa. These (group A) compared a group matched control...
Bioassay-guided fractionation of the root wood Zanthoxylum wutaiense led to isolation 11 new compounds, wutaiensol methyl ether (1), demethoxywutaiensol (2), wutaiensate (3), 7-hydroxyanodendroate (4), 7-methoxyanodendroate (5), wutaifuranol (6), 7-methoxywutaifuranol (7), 7-methoxywutaifuranal (8), wutaifuranate (9), 7-methoxybenzofuran-5-carboxylate (10), and wutaipyranol (12), together with another 37 known which one, 7-methoxybenzofuran-5-carboxaldehyde (11), was not previously as a...
Abstract The guanidine‐catalyzed 6‐ exo ‐ trig ‐type intramolecular asymmetric oxa‐Michael addition of α,β‐unsaturated esters with a 2‐hydroxyaryl moiety at the C‐5 carbon has been examined for construction chromane skeletons quaternary chiral center. bulkiness alkyl group and E / Z geometry ester function played important roles in induction (4 S ,5 )‐2‐[( R )‐1‐hydroxymethyl‐2‐phenylethylimino]‐1,3‐dimethylimidazolidine (or its enantiomer) carrying aryl pendants 4‐ 5‐positions was found to...
There are a number of reports indicating that <i>CYP2B6</i>*<i>6</i> (c.516G>T and c.785A>G) is responsible for decreased clearance efavirenz (EFV), although increased disposition cyclophosphamide (CPA) in individuals with this polymorphism was observed. Thus, we hypothesized the effects two single nucleotide polymorphisms (SNPs) on metabolism drugs might be considerably different between these agents. To clarify possibility, expressed major variants enzyme, CYP2B6.6 (Q172H K262R)...