Determination of carbon skeletons of microgram amounts of steroids and sterols by gas chromatography after their high-temperature catalytic reduction

Pyrolysis of amino acids. Mechanistic considerations

“…Results for 8-alanine (8) were reported previously,16 but additional information has been obtained pertinent to this study. The pyrolytic decomposition of the new members of the group, 8-amino-n-butyric acid (6) and 8-aminoisobutyric acid (7), is similar to that of 8-alanine. The most striking difference between the thermal decomposition of the a-and 8-amino acids is the almost total distinction between their primary modes of decomposition.…”

“…In the present system, a large quantity of amine is present following decarboxylation and a transalkylidenation reaction (eq 8) represents a pathway that provides for the formation of both ammonia and the jV-alkylaldimines. rch2ch2nh, RCH2CH=NH -:-RCH2CH=NCH2CH2R + NH3 (8) --(CH3)2CHCH=NH (7) Further, preliminary studies suggest that the yields of Nalkylaldimine and ammonia are directly correlated when conditions to reduce or increase their yields relative to the nitrile are introduced.…”

Mirasorvone: A masked 20-ketopregnane from the defensive secretion of a diving beetle ( Thermonectus marmoratus )

“…The high-temperature hydrogenolysis of mirasorvone was performed by a reaction gas chromatographic procedure with a precolumn of palladium catalyst prepared according to Beroza and Sarmiento (15,16). In an attempted hydrolysis experiment, mirasor vone was treated with 0.5 M ptoluenesulfonic acid in CH 3 CN͞H 2 O (4:1) at 50°C.…”

“…A high-temperature hydrogenolysis experiment performed with mirasorvone, which gave the same pattern of hydrocarbon products (GC-MS analysis) as that of an authentic sample of progesterone (8), established the presence of a pregnane skeleton (15,16). Because all natural pregnanes are oxygenated (or aminated) at C-3 and C-20, we assumed that mirasorvone must also be oxygenated at these sites.…”

Determination of the Structure of Organic Compounds by Gas Chromatography: The Carbon Skeleton Chromatography of Steroids

“…In this way the carbon skeleton of a compound Paper read at the Scotland and Northern Ireland Regional Meeting, Edinburgh, Marcb, 1969. available in only microgram quantities can be tentatively identified. Carbon skeleton chromatography can be applied to steroids and sterols (Adhikary and Harkness, 1969a). The method consists of high temperature catalytic reduction by injection of a solution into a stream of hydrogen flowing through a heated catalyst bed, in a siliconised glass tube.…”