Mechanism of stigmasterol dealkylation in insect

Deuterated stigmasterols (10, 11 and 12) were chemically synthesized and fed to silk-worm larvae. GC-MS analysis of the metabolites, cholesterol (4) and desmosterol (6), indicates the migration of 25-hydrogen to C-24 position during stigmasterol dealkylation. 22,24(28)-Dienes(8a and 8b) were shown to be converted to 22,24-diene (5), desmosterol and cholesterol.     

Core electron excitation spectra of diamond,graphite, and glassy carbon

Low-energy electron energy loss spectra in theC(1s) core electron excitation region have been measured in diamond, graphite and glassy carbon in the non-differentiated form. The background subtractedN(E) spectrum has been proved to reflect the density-of-states (DOS) of the conduction band well, and the conduction band structures of these materials have been elucidated. The energy positions of the symmetry points in their conduction bands have been determined from the second-derivative spectra, which were obtained by numerical differentiation of the measuredN(E) spectra.