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With 4-oxo-4,5,6,7-tetrahydrobenzothiophene and 2-methyl-3-oxothiophane-1-dioxide (III) as AB and D ring precursors respectively, (+/-)-3,17-dithia-A-nor-14 beta-estra-1,5(10),6,8-tetraene-17-dioxide (I) was synthesised following the modified Torgov method.
A novel polyhydroxylated steroid, named sartortuosterol A, with rare 3 alpha- and 6-hydroxyl groups, was isolated from the South China Sea soft coral Sarcophyton tortuosum Tixier-Durivault, and its structure was established as 24xi-methyl 5 alpha-cholestane-3 alpha, 6 beta, 9 alpha,25-tetrol 25-monoacetate from spectroscopic data and chemical conversions.
2 alpha,3 alpha-Dihydroxy-5 alpha-cholestan-6-one (3), which had the substitution pattern of brassinosteroids in the A/B-ring moiety, was transformed by Mycobacterium vaccae to give 2 alpha,3 alpha,6 alpha-trihydroxy-5 alpha-androstan-17-one (4) and 2 alpha-hydroxyandrost-4-ene-3,17-dione (5). The structures of these compounds were determined by spectroscopic methods, especially 1H nuclear magnetic resonance studies.
Fermentation of cholic acid with Arthrobacter simplex (IICB 227) under aerobic conditions yielded 3,12-dioxo-23,24-dinorchola-4,6-dienoic acid, 7 alpha-hydroxy-3,12-dioxo-23,24-dinorchol-4-enoic acid, 3 alpha, 7 alpha-dihydroxy-12-oxo-5 beta-cholan-24-oic acid, 3 alpha, 7 alpha-dihydroxy-12-oxo-5 beta-23,24-dinorcholan-22-oic acid, 7 alpha, 12 alpha-dihydroxy-3-oxo-5 beta-cholan-24-oic acid, 7 alpha-12 alpha-dihydroxy-3-oxo-4-cholenoic acid, 7 alpha, 12 alpha-dihydroxy-3-oxo-23,24-dinorchol-4-enoic acid, and methyl-3 alpha-7 alpha, 12 alpha-trihydroxy-5 beta-cholan-24-oate in addition to a new metabolite 2 beta-hydroxy-3,12-dioxo-23,24-dinorchola-4,6-dienoic acid. Each microbial metabolite was characterized by the application of various spectroscopic methods. The availability of some of the metabolites' enabled complete elucidation of their 13C NMR spectra.
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The absorbance spectrum of tullidinol, a tullidora (Karwinskia humboldtiana) toxin, showed peaks at 260 and 410 nm when dissolved in ethanol; the second peak was linearly related to toxin concentration. Silica gel thin layer chromatograms of tullidinol solutions showed a single, yellow spot with an Rf of 0.76. A single dose of tullidora fruit homogenate was orally given to male Wistar rats; the absorbance spectrum of serum from tullidora-treated rats showed peaks at 300 nm and at 410 nm; the second peak was absent in serum from control rats. No spots were detected in chromatograms of normal serum, but a yellow spot with the same Rf as that of tullidinol was found in the serum of tullidora-treated rats. We conclude that tullidinol was detected in the serum of treated animals and that the methods we used for its detection may also help to diagnose accidental tullidora poisoning in cattle and human beings.
A peptide toxin was isolated from the cyanobacterium Nodularia spumigena by high performance liquid chromatography (HPLC). The i.p. LD50 of the toxin was 50 micrograms/kg mouse with death within 1-3 hr. The major effects of the toxin were seen in the liver in the form of extensive haemorrhages. Amino acid analysis showed the presence of equimolar amounts of glutamic acid, beta-methyl-aspartic acid, and arginine. The toxicological and some of the chemical properties of the isolated toxin were similar to those reported for hepatotoxins isolated from the cyanobacterium Microcystis aeruginosa.
A very potent non-protein toxin was isolated from the sea anemone Radianthus macrodactylus with the use of chromatography on polytetrafluoroethylene, CM-Sephadex C-25 and by cation and anion exchange HPLC. The toxin was identified as palytoxin by u.v.-, i.r.- and 500 MHz 1H NMR spectroscopy. Its LD50 was 0.74 +/- 0.29 micrograms/kg by i.v. injection into mice. So far, palytoxin has been associated with zoanthids only. The toxin caused the loss of haemoglobin from erythrocytes but only in about 2 hr after the beginning of incubation, which is characteristic for palytoxin from zoanthids. Sea anemone palytoxin was divided into major and minor components by HPLC. The latter proved to be a product of degradation of palytoxin.
A new marine neurotoxin was isolated from a water extract of the New Zealand shellfish, Austrovenus stutchburyi, by chromatography on columns of Sephadex G-15 and LH-20, followed by reverse-phase HPLC. It was identified as (4-methoxycarbonylbutyl)trimethyl-ammonium chloride, and this was confirmed by synthesis.
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