The biosynthesis of plant alkaloids and nitrogenous microbial metabolites

The biosynthesis of plant alkaloids and nitrogenous microbial metabolites

“…ref. 4 (88) in Dichotomomyces cejpii to an insignificant extent." Potassium ["C, 14C, l5N]cyanide and [14C, 13C, 15N]-2hydroxy-4-methylvaleronitrile (seen either as a 'protected' form of cyanide for safe delivery to the site of biosynthesis or as a representative of amino-acid metabolism found in plants which affords cyanogenic glycosides) were both satisfactory precursors for (88) but only the 0-methyl group was labelled in each case.…”

“…3, p. 163; ref. 2, p. 181) it has been shown that the ester (1) is an intact precursor for the alkaloid (4). A possible biosynthetic intermediate beyond (1) was considereds to be 2,3didehydrococaine [as (2)].…”

“…It was essentially antipodal with respect to natural cocaine. Thus it was concluded that the racemic (2) which was fed underwent hydrolysis but only the ( + )-enantiomer was subsequently reduced to ecgonine methyl ester (3) en route to cocaine (4). The evidence then points clearly to (3), but not 2,3-didehydrococaine [as (2)], being an intermediate in the biosynthesis of cocaine (4).…”

The biosynthesis of plant alkaloids and nitrogenous microbial metabolites

“…If (-)-sparteine is formed via the intermediate ( 24) then (+)-sparteine is apparently formed from its enantiomer (for background information, see Scheme 2 in ref. 4).…”

Quinolizidine Alkaloids: Biochemistry, Metabolism, and Function in Plants and Cell Suspension Cultures

“…Quinolizidine alkaloids (QA) have been studied in a number of laboratories during the last 100 years. Although of minor pharmaceutical importance (sparteine is used as an antiarrhythmic compound), interest in this group of alkaloids has increased within the last 15 years, which can be seen in the growing number of articles and reviews in this field (7,8,24,58,(91)(92)(93).…”