Three new peroxides from the sponge Plakinastrella species.

Two new five-membered-ring peroxide acids, plakinic acid F (3) and epiplakinic acid F (4), and a new peroxide-lactone, plakortolide F (5), were isolated from a sponge of the genus Plakinastrella collected from Felicite Island, Seychelles. The structures were elucidated through spectral analysis. The free acids 3 and 4 exhibit moderate antifungal activity against Candida albicans with minimum inhibitory concentrations of 25 micrograms/mL (SDB) and 3.1 micrograms/mL (RPMI) for 3, and 25 micrograms/mL (SDB) and 6.25 micrograms/mL (RPMI) for 4, respectively. Both also showed moderate in vitro inhibition of Aspergillus fumigatus with IC90's of 25 micrograms/mL.

Microxine, a new cdc2 kinase inhibitor from the Australian marine sponge Microxina species.

A new purine derivative microxine (1) was isolated from the Australian marine sponge Microxina sp. The compound was isolated via reversed-phase chromatography and its structure determined spectroscopically. Microxine was found to weakly inhibit cdc2 kinase activity with an IC(50) of 13 microM.

Bis(sulfato)-cyclosiphonodictyol A, a new disulfated sesquiterpene-hydroquinone from a deep water collection of the Marine sponge Siphonodictyon coralliphagum.

A new compound, bis(sulfato)-cyclosiphonodictyol A [1], which inhibits the binding of [3H]-LTB4 to intact human neutrophils with an IC50 value of 44 microM, was isolated from the sponge Siphonodictyon coralliphagum. The sponge was collected using the Johnson-Sea-Link manned submersible at a depth of 195 feet in the Bahamas. The compound was isolated via reversed-phase chromatography and its structure determined spectroscopically. To the best of our knowledge, 1 is the first marine-derived compound with two aromatic sulfate ester functionalities, and is also the first in the siphonodictyal series to contain an oxepane functionality.

Sesquiterpene-derived metabolites from the deep water marine sponge Poecillastra sollasi.

Six sesquiterpene-derived compounds, 1-6, which we call sollasins a-f, have been isolated from a deep water specimen of the sponge Poecillastra sollasi. The structures were elucidated by comparison of spectral data to related metabolites and confirmed using spectroscopic methods. The compounds inhibit the growth of the pathogenic fungi Candida albicans and Cryptococcus neoformans and the P-388 and A-549 tumor cell lines. Compounds 3 and 4 show weak inhibition of binding of [125I] angiotensin II to rat aorta smooth muscle cell membranes.

A new prenylated isoflavone and long chain esters from two Erythrina species.

Two new compounds, a long chain ester 1 of p-coumaric acid and a prenylated isoflavone, senegalensin [5], 5,4'-dihydroxy-8-(gamma,gamma-dimethylallyl)-[5"-(hydroxyisopropyl ) (2",3":6.7)] isoflavone, in addition to a known long chain ester 2 of ferulic acid, have been isolated and characterized from the stem bark of the Cameroonian medicinal plant Erythrina senegalensis. Another known compound 3, a long chain ester of ferulic acid, was isolated from Erythrina excelsa. The structures of all the compounds were determined by spectroscopic techniques.