Eryngial (trans-2-dodecenal), a bioactive compound from Eryngium foetidum: its identification, chemical isolation, characterization and comparison with ivermectin in vitro.

Methanol-water (4:1, v/v) crude extracts (50 mg mL(-1)) of 25 Jamaican medicinal plants were screened in vitro for anthelmintic activity using infective third-stage larvae of Strongyloides stercoralis. The most effective extract was further chemically scrutinized to isolate and identify the source of the bioactivity, and the efficacy of this compound was compared with ivermectin. Eosin exclusion (0.1 mg mL(-1)) served as the indicator of mortality in all bioassays. A crude extract of Eryngium foetidum (Apiaceae) was significantly (Probit Analysis, P<0.05) more potent than the other plant extracts, taking 18.9 h to kill 50% (LT50) of the larvae. Further, the petrol extract of E. foetidum was significantly more effective (Probit Analysis, P<0.05) at killing the larvae (LT50, 4.7 h) than either its methanol-water or dichloromethane extract. The latter two effected less than 1% larval mortality after 120 h. With bioassay-driven column chromatography of the petrol extract, trans-2-dodecenal (eryngial) was identified and chemically isolated as the main anthelmintic compound in E. foetidum. There was a significant difference between the 24 h LD50 values (mm) of trans-2-dodecenal (0.461) and ivermectin (2.251) but there was none between the 48 h LD50 values (mm): trans-2-dodecenal (0.411) and ivermectin (0.499) in vitro.

Steroid transformations with Exophiala jeanselmei var. lecanii-corni and Ceratocystis paradoxa.

The fungi Exophiala jeanselmei var. lecanii-corni [IMI (International Mycological Institute) 312989, UAMH (University of Alberta Microfungus Collection and Herbarium) 8783] and Ceratocystis paradoxa (IMI 374529, UAMH 8784) have been examined for their potential in steroid biotransformation. The study has determined that E. jeanselmei var. lecanii-corni effected overall anti-Markovnikov hydration on dehydroisoandrosterone, and side-chain degradation on a variety of pregnanes. Both ascomycetes were found to carry out redox reactions of alcohols and ketones as well as 1,4 reduction of alpha,beta-unsaturated carbonyl systems.

Steroid transformations with Fusarium oxysporum var. cubense and Colletotrichum musae.

The utility of two locally isolated fungi, pathogenic to banana, for steroid biotransformation has been studied. The deuteromycetes Fusarium oxysporum var. cubense (IMI 326069, UAMH 9013) and Colletotrichum musae (IMI 374528, UAMH 8929) had not been examined previously for this potential. In general, F. oxysporum var. cubense effected 7alpha hydroxylation on 3beta-hydroxy-delta5-steroids, 6beta, 12beta, and 15alpha hydroxylation on steroidal-4-ene-3-ones, side-chain degradation on 17alpha,21-dihydroxypregnene-3,20-diones, and 15alpha hydroxylation on estrone. Both strains were shown to perform redox reactions on alcohols and ketones.

Malyngamides O and P from the sea hare Stylocheilus longicauda.

Two new malyngamides, O (1) and P (2), were isolated from the sea hare Stylocheilus longicauda. The structures were elucidated by analysis of their 1D and 2D NMR spectra.

Gelliusterols A--D, new acetylenic sterols from a sponge, Gellius species.

New acetylenic sterols, gelliusterol A (1, 26,27-bisnorcholest-5-en-23-yn-3 beta,7 alpha-diol), its corresponding 7-ketone, gelliusterol B (2, 26,27-bisnorcholest-5-en-23-yn-3 beta-ol-7-one), and gelliusterols C (4, cholest-5-en-23-yn-3 beta,7-one) and D (5, cholest-5-en-23-yn-3 beta,25-diol-7-one), were isolated from an unidentified species of sponge, Gellius sp. The structures of the steroids were established from spectroscopic data.

Two complex proline esters from the sea hare Stylocheilus longicauda.

Investigation of Stylocheilus longicauda led to the isolation of chlorinated metabolites, makalika ester (1) and makalikone ester (2). Also reported is the isolation of lyngbyatoxin A acetate (3). The structures of the new compounds are based on spectroscopic data obtained from 1D and 2D NMR experiments.

New skeletal sesquiterpenoids, caprariolides A-D, from Capraria biflora and their insecticidal activity.

Four structurally novel isomeric sesquiterpenes have been isolated from the aerial parts of Capraria biflora. Caprariolides A (1), B (2), C (3), and D (4) have been determined by NMR spectroscopy experiments to be the (3S,5S,9R), (3R,5S,9R), (3R,5R,9R), and (3S,5R, 9R) isomers of 7-(furan-3'-yl)-3,9-dimethyl-1-oxaspiro[4. 5]dec-6-en-2-one, respectively. Both 1 and 2 were found to exhibit insecticidal activity against adult Cylas formicarius elegantulus, one of the most destructive insect pests of the sweet potato, Ipomoea sp.