Ronald H. Thomson

Sterols from the sponges Cliona celata grant and Hymeniacidon perleve montagu

Abstract The sterols of Cliona celata have been identified as cholesterol (predominant), 24-norcholesta-5,22-dien-3β-ol, 22,23-dehydrocholesterol, 24-methylenecholesterol, brassicasterol, 22,23-dihydrobrassicasterol, poriferasterol, and clionasterol, while those found in Hymeniacidon perleve were cholestanol (predominant), 24-norcholesta-22-en-3β-ol. 22,23-dehydrocholestanol, 24-methylenecholestanol, fucosterol, brassicasterol, β-sitosterol, and neospongosterol.

Caldariellaquinone, a unique benzo[b]thiophen-4,7-quinone from Caldariella acidophila, an extremely thermophilic and acidophilic bacterium

Caldariellaquinone {6-(3,7,11,15,19,23-hexamethyltetracosyl)-5-methylthiobenzo[b]thiophen-4,7-quinone (7)} has been isolated from cultures of Caldariella acidophila, an extremely thermophilic and acidophilic bacterium. The structure was determined by degradation, spectroscopic, and 13C biosynthetic studies.

Gadusol, a metabolite from fish eggs

Abstract Gadusol, a metabolite from the eggs of cod and other fishes, has been identified as 1,4,5-trihydroxy-2-methoxy-5-hydroxymethylcyclohex-1-en-3-one, related to the mycosporines and analogous compounds.

The isolation of four aminocyclohexenimines (mycosporines) and a structurally related derivative of cyclohexane-1:3-dione (gadusol) from the brine shrimp, Artemia

1. 1. Mycosporines, N-substituted amino acid derivatives of 1,5-dihydroxy-5-hydroxymethyl-2-methoxycyclohex-1-en-3-one, were isolated from dormant embryos (cysts) of Artemia. The major component in all strains was mycosporine (-Gly:-Ser). Smaller amounts of other mycosporines containing glycine and threonine, glycine and alaninol as well as glycine and aspartic acid residues were identified in cysts of a strain from Brazil. 2. 2. Free amino acids were released from mycosporines by treatment with either bromine water or an iodine peroxidase (EC 1.11.1.8). 3. 3. The amount of mycosporines in developing cysts decreased while motile nauplii contained only gadusol (1,4,5-trihydroxy-5-hydroxymethyl-2-methoxycyclohex-1-en-3-one).

New terpenoid aldehydes from Kigelia pinnata: crystal structure of pinnatal

From the root bark of Kigelia pinnata (Bignoniaceae) two aldehydes, norviburtinal(6-formylcyclo-penta[c]pyran) and pinnatal, 11-formyl-2, 3, 3a, 5, 10, 10a, 11, 11a-octahydro-8-hydroxy-3, 11-dimethyl-3, 10a-epoxy-1H--cyclopent[b]anthracene-5, 10-dione, have been isolated. The structures were determined by spectroscopic methods, and X-ray crystallographic analysis of pinnatal.

Laurenyne, a new acetylene from Laurencia obtusa: crystal structure and absolute configuration

Abstract Laurenyne, a new chloroacetylene from the red form of the alga Laurencia obtusa has been identified and its crystal structure determined.

The cymopols, a group of prenylated bromohydroquinones from the green calcareous alga Cympolia barbata

Seven new hydroquinones have been isolated from the green alga Cymopolia barbata. These are cymopol [2-bromo-5-(3,7-dimethylocta-2,6-dienyl)hydroquinone] and its monomethyl ether, cyclocymopol [1-bromo-3-(4-bromo-2,5-dihydroxybenzyl)-2,2-dimethyl-4-methylenecyclohexane] and its monomethyl ether, cymopolone [(4-bromo-2,5-dihydroxyphenyl)trans-(2,6-dimethylhepta-1,5-dienyl) ketone], and its cis-isomer, and cymopochromenol [7-bromo-6-hydroxy-2-methyl-2-(4-methylpent-3-enyl)-2H-1-benzopyran]. The structure and absolute stereochemistry of cyclocymopol monomethyl ether acetate were established by X-ray crystallography.

New lignans in Conocarpus erectus

Abstract The wood of Conocarpus erectus contains conocarpol and 2′-methoxyconocarpol, simple 1,4-diarylbutane-type lignans, and conocarpan, a lignan of the dehydrodi- iso eugenol type.

Isoflavones from Dipteryx odorata

Abstract Five isoflavones have been isolated from the heartwood of Dipteryx odorata: retusin, retusin 8-methyl ether, 3′-hydroxyretusin 8-methyl ether, odoratin (7,3′-dihydroxy-6,4′-dimethoxyisoflavone) and dipteryxin (7,8-dihydroxy-6,4′-dimethoxyisoflavone).

Distribution of naturally occurring quinones

Angiosperms, fungi (including lichens), and bacteria are the main sources of natural quinones. Small numbers are present in algae, ferns, conifers, sponges, echinoderms, other marine animals, and arthropods. In angiosperms quinones have some chemotaxonomic value at the genus and family level but more surveys are required.