Tröger's base. An alternate synthesis and a structural analog with thromboxane A2 synthetase inhibitory activity.

The synthesis of 2,8-dimethyl-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine (Tröger's base) from p-toluidine and of two Tröger's base analogs from other anilines by reaction with hexamethylenetetramine in trifluoroacetic acid is described. 2,3,6,7-Tetrahydro-9-methyl-2,6-di-p-tolyl-1H,5H-pyrimido[5,6,1-ij] quinazoline is formed as a secondary product in the reaction of p-toluidine and hexamethylenetetramine. One of the Tröger's base analogs, 2,8-bis(3'-pyridylmethyl)-6H,12H-5,11-methanodibenzo[b,f][1,5]d iazocine (5), is an effective inhibitor of the enzyme, thromboxane A2 (TxA2) synthase, with an ED50 of 30 ng/mL in a specified in vitro assay. Three analogs having substituents on the bridging methylene group of the bicyclic nucleus of the Tröger's base structure were prepared, but all were considerably less active than the aforementioned compound in the inhibition assay. The structures of these inhibitors of TxA2 synthase fall outside the classical structure-activity relationship that has been established for this class of enzyme inhibitors.

Antibiotics produced by Streptomyces ficellus. I. Ficellomycin.

Ficellomycin is a new basic antibiotic produced by Streptomyces ficellus. Ficellomycin, C13H24N6O3, inhibits the growth of gram-positive bacteria in vitro and is effective in the treatment of experimental Staphylococcus aureus infections in mice.

Inhibition of microbial growth by fatty amine catalysts from polyurethane foam test tube plugs.

When polyurethane foam test tube plugs are autoclaved, they release volatile fatty amines that inhibit the growth of some microorganisms. The chemical structures of these amines were determined by the use of a gas chromatograph-mass spectrometer. They are catalysts used to produce the foam. The problem of contaminating growth media with toxic substances released from polymeric materials is discussed.

Discovery of an arachidonic acid C-8 lipoxygenase in the gorgonian coral Pseudoplexaura porosa.

The gorgonian coral Pseudoplexaura porosa contains a lipoxygenase capable of converting exogenous arachidonic acid into (8R)-8-hydroperoxy-5,9,11,14-eicosatetraenoic acid. The (8R)- (or 8-L-) configuration in this product, opposite to that observed in previously reported 8-lipoxygenase products, was determined unambiguously by comparison of oxidative ozonolysis fragments with authentic malic acid-derived standards. Extracts from the coral contained no detectable prostaglandins (PGAs, PGBs, PGEs, or PGFs). Although arachidonic acid represents one of the most abundant of the common fatty acids found in the phospholipid and total lipid fractions of P. porosa, products ascribable to the arachidonic acid 8-lipoxygenase pathway ((8R)-8-hydroperoxy-5,9,11,14-eicosatetraenoic acid, the corresponding alcohol 8-hydroxyeicosatetraenoic acid, further transformation products) have not yet been identified in the coral extracts. The physiological significance of the 8-lipoxygenase in this species remains a matter for speculation.