Determination of the transglycosidation activity of NAD+ glycohydrolases with 4-(2′-alkyl-sulfanyl-vinyl)-pyridine derivatives generating chromophoric NAD+ analogs
摘要:
The base exchange of nicotinamide with pyridine derivatives 1a-5a, catalyzed by pig brain NAD(+) glycohydrolase and ADP-ribosyl cyclase from Aplysia californica, generated the corresponding NAD(+) analogs 1b-5b. These analogs exhibited a high absorbance band in the visible region. The transglycosidation rate was determined by monitoring the absorbance increase. Among the tested derivatives, (E)-4-[2-(methylsulfanyl)-vinyl]-pyridine 1a was the most suitable substrate for pig brain NAD(+) glycohydrolase while 4-[1,3]-dithiolan-2-ylidenemethyl-pyridine 3a was the most efficient for ADP-ribosyl cyclase from A. californica. (C) 2003 Elsevier Science (USA). All rights reserved.
Synthetic studies of imbiline 1, a constituent of Eupomatia species
摘要:
Imbiline 1 (la), a constituent of Eupomatia species, was synthesized from 4-methoxy-1-naphthylamine hydrochloride (8) in seven steps. A reaction of aldehydes and methyl methylthiomethyl sulfoxide was also studied. (C) 2003 Elsevier Science Ltd. All rights reserved.