Alkaloids of bacteria and cacti and a novel synthesis of Dihydro-p-dithiins and dihydrodithiepins

Abstract

A method is given for the determination of alkaloids in fresh bacterial cultures and cactus plants using alkaloid precipitating reagents in conjunction with gas chromatographic analysis. In a screening of 30 species of bacteria, the following ten species not previously known to contain alkaloids yielded base fractions that gave positive reactions with two reagents, and in addition most contained peaks in their chromatograms indicating compounds with molecular weights greater than 175: Bacillus cereus var. mycoides, Corynebacterium pseudodiphtheriticum, Neisseria perflava, Proteus mirabilis, Pseudomonas taetrolens, P. fluoroescens, P. mildenbergii, and Streptococcus lactis; and the following nine species gave a positive reaction with one reagent and had components with mol. Wt. greater than 175: Acetobacter aceti, B. circulans, B. cereus, Micrococcus roseus, Pseudomonas putida, P. fragi, Proteus vulgaris, Sarcina lutea, and Vibrio percolans. Serratia marcescens and Pseudomonas aeruginosa, previously reported to contain alkaloids, gave positive reactions with both reagents and contained compounds with mol. Wt. greater than 175. Four species of cacti were examined and all were found to contain alkaloids. The cactus Carnegiea gigantea was found to contain two major alkaloids, not one as reported by Heyl in 1928. The alkaloid fraction of this cactus was separated into its two components, carnegine, and a new cactus alkaloid, which was named gigantine. It is shown that the new alkaloid has partial structure I. while spectroscopic and biogenetic considerations indicate that gigantine probably has structure II. [Diagrams] During the synthesis work, a novel method for the preparation of dihydro-p-dithiins and dihydrodithiepins was discovered: [Diagram] and a mechanism for the reaction is proposed.