Diversity of gossypol clathrates with pyrazine

Thermodynamic stability of hydrogen clathrates.

The stability of the recently characterized type II hydrogen clathrate [Mao, W. L., Mao, H.-K., Goncharov, A. F., Struzhkin, V. V., Guo, Q., et al. (2002) Science 297, 2247-2249] with respect to hydrogen occupancy is examined with a statistical mechanical model in conjunction with first-principles quantum chemistry calculations. It is found that the stability of the clathrate is mainly caused b...

Biosynthesis of Gossypol

Based on the previous observations that gossypol is biosynthetically formed from acetate, and from the location of the incorporated 1% atoms, gossypol biosynthesis via the isoprenoid pathway has been postulated. To support this hypothesis, the incorporation of mevalonate-2J4C (a key intermediate in the isoprenoid pathway) into gossypol as well as the distribution of the radioactivity in the gos...

Studies on pyrazine derivatives. XLVII. Synthesis and antibacterial activity of novel pyrazine derivatives with amidoxime moiety.

The new pyrazine derivatives exhibiting an antibacterial activity have been synthesized. Initial amidoxime 1 was obtained in the reaction of pyrazinecarbonitrile with hydroxylamine. Upon treatment of amidoxime with methyl iodide O-methyl derivative 2 was formed. Both amidoximes were transformed into imidoyl chlorides 3, 4. Then the chloride atom in those derivatives was substituted with various...

SYNTHESES AND REACTIONS OF PYRAZINE AND QUINOXALINE 1.1 Pyrazine

Gossypol inhibition of adenylate cyclase.

Gossypol, a polyphenolic binaphthalene -dialdehyde reputed to exert contraceptive action in males, reversibly inhibits adenylate cyclase [ATP pyrophosphate lyase (cyclizing), EC 4.6.1.1] in a concentration-dependent manner. In membranes prepared from a variety of organs, the half-maximal inhibitory concentration (IC50) ranges from 75 microM (rat Leydig tumor cells) to 250 microM (rat liver memb...