Two types of reaction have been described in which a reversal of electron transfer may occur: (a) energy-linked reduction of pyridine nucleotide in the presence of a flavin-linked substrate (I) and (b) energy-linked oxidation of cytochrome and reduction of pyridine nucleotide (2). In the latter, the presence of both oxidized and reduced forms of the respiratory carriers suggests that the system...

The purpose of the present study was to make available a simple quantitative procedure for total heme pigments in feces, urine, and blood plasma or serum. It was planned to convert these substances to pyridine ferrohemochromogen, which is known to have stronger absorption than other easily prepared heme compounds, and to measure this absorption under standard conditions with the Evelyn photoele...

Three isomeric pyridine-containing L-glutamic lipids formed organogels in DMSO and self-assembled into different nanostructures of nanofiber, nanotwist and nanotube depending on the substituent position in the pyridine ring.

A number of manganese-based catalysts employing ligands whose structures incorporate pyridyl groups have been reported previously to achieve both high turnover numbers and selectivity in the oxidation of alkenes and alcohols, using H(2)O(2) as terminal oxidant. Here we report our recent finding that these ligands decompose in situ to pyridine-2-carboxylic acid and its derivatives, in the presen...

D-Glyceraldehyde-3J4C was synthesized and administered to intact Nicotiana rustica. Degradation of the pyridine moiety of nicotine produced by these plants showed that over half of the incorporated 1% was in position 4 of the pyridine ring, and the remainder of the radioactivity was divided almost equally among carbon atoms 2, 3, and 6. Lack of randomization of the label in positions 4, 5, and ...

A series of new PEPPSI (Pyridine Enhanced Precatalyst Preparation Stabilization and Initiation) themed precatalysts of abnormal N-heterocyclic carbenes for the highly desirable Cu-free and amine-free Sonogashira coupling in air in a mixed-aqueous medium is reported. Specifically, the PEPPSI themed (NHC)PdI2(pyridine) type precatalysts, 1b-4b, efficiently carried out the highly convenient Cu-fre...