C-24 Stereochemistry of Marine Sterols: (22E)-24-(Isopropenyl)-22-dehydrocholesterol and 24-Isopropenylcholesterol

May 22 - 24 2011

This paper presents a stochastic modeling framework for store-and-forward packet routing protocols in Wireless Body Area Networks (WBAN). A prototype WBAN has been constructed for experimentally characterizing and capturing on-body topology disconnections in the presence of ultra short range radio links, unpredictable RF attenuation, and human postural mobility. Delay modeling techniques for ev...

24-Methyl-23-dehydrocholesterol: a new sterol intermediate in C-24 demethylation from the nematodes Panagrellus redivivus and Caenorhabditis elegans?

Panagrellus redivivus produced 24-methyl-23-dehydrocholesterol as 4.0% of the 4-desmethylsterols when propagated in a medium containing campesterol as the dietary sterol. The re-examination of previous data revealed that Caenorhabditis elegans produced 1.8% 24-methyl-23-dehydrocholesterol when propagated in medium containing campesterol. 24-Methyl-23-dehydrocholesterol was not detected when the...

Two new 24-isopropenyl-lanostanoids from Tillandsia brachycaulos.

The leaves of Tillandsia brachycaulos afforded two novel tetracyclic triterpenoids identified as (24S)-24-isopropenyl-29-nor-5alpha-lanosta-7-en-3beta-ol (1) and (24S)-24-isopropenyl-29-nor-5alpha-lanosta-7-en-3-one (2), in addition to the known isopimaric acid (3) and chlorogenic acid (4). Their structures were elucidated on the basis of spectral analysis, including homo- and heteronuclear cor...

Steric effects at C-20 and C-24 on the metabolism of sterols by Tetrahymena pyriformis.

Cultures of Tetrahymena pyriformis were incubated with various sterols and the extent of dehydrogenation at C-7 and C-22 was determined. The sterols incubated were desmosterol, 22-dehydrodesmosterol, 24-methyldesmosterol, 24 alpha-methylcholesterol (campesterol), 24-methylene-cholesterol, isohalosterol (26,27-bisnorcampesterol, also known as 24,24-dimethylchol-5-en-e beta-ol, a naturally occurr...

Connecticut College News Vol. 24 No. 22