Abstract An efficient stereocontrolled preparation of 2-substituted pyrrolidines and 5-substituted indolizidin-7-ones, by using chiral N-tert-butanesulfinyl imines derived from 4-halobutanal as starting materials, is detailed. Addition Grignard reagents a decarboxylative Mannich­ reaction with β-keto acids involving these proceeded high diastereoselectivity. The synthesis the pyrrolidinic alkal...

Efficient asymmetric synthesis of spiro-2(3H)-furanones was achieved via phase-transfer-catalyzed highly enantioselective alkynylation of cyclic β-keto esters with hypervalent iodine reagents.

Four new minor diterpene glycosides with a rare α-glucosyl linkage were isolated from a cyclodextrin glycosyltransferase glucosylated stevia extract containing more than 98% steviol glycosides. The new compounds were identified as 13-[(2-O-β-D-glucopyranosyl-3-O-(4-O-α-D-glucopyranosyl)-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-α-D-glucopyranosyl-β-D-glucopyran...

Room temperature, light induced (P700(+)-P700) Fourier transform infrared (FTIR) difference spectra have been obtained using photosystem I (PS I) particles from Synechocystis sp. PCC 6803 that are unlabeled, uniformly (2)H labeled, and uniformly (15)N labeled. Spectra were also obtained for PS I particles that had been extensively washed and incubated in D(2)O. Previously, we have found that ex...

Chemo-enzymatic synthesis of ester-linked 2-phenylindole-3-carboxaldehyde-glucose conjugate (2-phenylindole-3-carboxyl-10″-O-β-D-glucosyl ester) was achieved by using plant cell cultures as biocatalysts. The anticancer agent, 2-phenylindole-3-carboxaldehyde, induced apoptosis in cells, whereas 2-phenylindole-3-carboxyl-10″-O-β-D-glucosyl ester showed no cytotoxicity and induced no apoptosis.

Photooxygenation of (β-keto)-2-substituted furans leads, in a one pot operation, to functionalized 3(2H)-furanones with good to excellent yields. This methodology was applied as a key-step to the concise and biomimetic synthesis of the sesquiterpene merrekentrone C. The precursor to merrekentrone C, keto difuran, was synthesized using a cross coupling of α-iodo-3-acetylfuran with an alkenyl fur...

The specific mechanisms by which skin blood flow increases in response to a rise in core body temperature via cutaneous active vasodilation are poorly understood. The primary purpose of this study was to determine whether the cyclooxygenase (COX) pathway contributes to active vasodilation during whole body heat stress (protocol 1; n = 9). A secondary goal was to verify that the COX pathway does...

A new one-pot approach for the synthesis of aryl a-keto ester based on the diazo transfer and oxidation of diazo group is developed. 2005 Elsevier Ltd. All rights reserved. 1 3 Ar OMe O [O] Ar OMe O O Ar OMe N2 [O] Base ArSO2N3 a-Keto acids and esters have been important compounds as natural products and as the building blocks in organic synthesis. Over the past decades, various methods have be...

Chlorophyll-a plays a fundamental role in the solar energy conversion processes that occur in oxygen evolving organisms, such as plants algae and cyanobacteria. To study the chlorophyll-a species at the heart of these solar conversion processes FTIR difference spectroscopy has been a valuable tool. However, FTIR difference spectra are only partially understood. To gain a more detailed understan...