Shoji Konosu

Goniodomin a, a novel polyether macrolide from the dinoflagellate goniodoma pseudogoniaulax

Abstract A novel antifungal polyether macrolide, goniodomin A, was isolated from the dinoflagellate Goniodoma pseudogoniaulax collected in the rock pool. Its structure was elucidated to be 1 on the basis of spectral data.

Comparison of carotenoids in the ovaries of marine fish and shellfish

1. The following carotenoids were isolated and identified: astaxanthin diester, tunaxanthin monoester, astaxanthin monoester, tunaxanthin, astaxanthin, doradexanthin, lutein, zeaxanthin, idoxanthin, triol and tetrol from nine species of fish; astaxanthin diester, astaxanthin monester, astaxanthin, doradexanthin, zeaxanthin, idoxanthin and tetrol from four species of crustacean, astaxanthin, pectenolone, pectenoxanthin, pectenol and tetrol from four species of scallop. 2. Tunaxanthin monoester and astaxanthin diester were major carotenoids in skipjack and Pacific cod, respectively. 3. The concentration of carotenoids ranged 0.065-1.95, 1.30-5.91 and 1.56-7.15 mg per 100 g ovary for fish, crustacean and scallop, respectively. 4. The species- and tissue-specificity of ovarian carotenoids and their possible role are discussed.

Bioactive marine metabolites II. Halistanol sulfate, an antimicrobial novel steroid sulfate from the marine sponge halichondria cf. moorei bergquist☆

Abstract A new C29 a steroid sulfate, 24ξ,25-dlmethylcholestane-2β,3α,6α-triyl trisodium sulfate has been isolated from the Okinawan sponge Halichondria cf. moorei Bergquist as an antimicrobial constituent.

Bioactive marine metabolites. VI: Structure elucidation of discodermin A, an antimicrobial peptide from the marine sponge Discodermia kiiensis

The structure of an antimicrobial peptide discodermin A isolated from the marine sponge Discodermia kiiensis has been elucidated as CHO-d-Ala-l-Phe-d-Pro-d-t-Leu-l-t-Leu-d-Trp-l-Arg-d-Cys(O3H)-l-Thr-l-MeGln-d-Leu-l-Asn-l-Thr-Sar.

Bioactive marine metabolites VII. Structures of discodermins B, C, and D, antimicrobial peptides from the marine sponge discodermia kiiensis

Abstract Isolation and structure elucidation of three peptide antibiotics, discodermins B, C, and D, from the marine sponge, Discodermia kiiensis , and the revised structure of discodermin A are described.

Occurrence of toxic crabs in Ryukyu and Amami Islands

Two typical cases of illness associated with the ingestion of toxic crabs are described. The signs were characterized by vomiting, paralysis, and rapid death. In the screening test for toxic crabs, two species, Zosimus aeneus and Platypodia granulosa, were found to contain a paralytic toxin showing a dose-death time curve similar to that of tetrodotoxin. In both species the toxin was found to be present mostly in the exoskeleton and muscle of appendages and only slightly in the cephalothorax. A marked individual variation of toxicity was also recognized. The toxin was easily dialyzable, soluble in water and methanol, and insoluble in most fat solvents.

Origin of tunaxanthin in the integument of yellowtail (Seriola quinqueradiata)

Abstract 1. 1. Bioconversion of astaxanthin and lutein was examined by feeding experiments of yellowtail. 2. 2. Carotenoid contents in the integuments of the fish fed the diets supplemented with astaxanthin or lutein were markedly increased. 3. 3. In every test fish, the same nine carotenoids, tunaxanthins C, B and A, 3′-epilutein, lutein, zeaxanthin, diatoxanthin, cynthiaxanthin and β-carotene triol were detected. 4. 4. Astaxanthin was presumably metabolized to tunaxanthins C or B, via β-carotene triol, zeaxanthin and 3′-epilutein. Lutein seemed to be metabolized to tunaxanthins C or B, via 3′-epilutein. 5. 5. Sources of tunaxanthin in the integuments of marine fish were estimated to be astaxanthin, lutein and probably zeaxanthin all of which are very common carotenoids in marine organisms.

Pigmentation of juvenile coho salmon with carotenoid oil extracted from Antarctic krill

Abstract Pigmentation of the flesh of juvenile coho salmon ( Oncorhynchus kisutch ) in fresh water was investigated by feeding diets supplemented with an oil extracted from Antarctic krill ( Euphausia superba ). The oil contained ( 3R,3′R )-astaxanthin diester as a main carotenoid. Small fish (80 g) fed the supplemented diet showed very little flesh pigmentation. However, marked pigmentation was observed when fish with an initial weight of approximately 180 g were reared on diets containing 7.2 mg astaxanthin 100 g diet for 4 weeks. The carotenoid content of flesh was about 0.2 mg 100 g and it consisted almost exclusively of astaxanthin. Fish fed a diet containing krill oil for 8 weeks retained most of the carotenoids laid down in the flesh throughout a following 24-week period on a non-carotenoid diet. Structural isomer composition of astaxanthin in the flesh of fish fed a diet containing 14.4 mg astaxanthin 100 g was 93, 4–5 and 2–3% for all- trans -, 9- cis - and 13- cis -astaxanthin at the end of the experiment, respectively. Optical isomer composition of the all- trans -astaxanthin fraction was 74, 10 and 16% for ( 3R,3′R )-, ( 3S,3′R ) meso - and ( 3S,3′S )-astaxanthin, respectively. No isomerization of astaxanthin deposited in the flesh was found.

Metabolism of dietary carotenoids in eggs of red sea bream

Abstract 1. 1. Transfer of dietary carotenoids into eggs was examined by a feeding experiment of red sea bream broodstock. 2. 2. Levels of carotenoids incorporated in the eggs were approximately 60 μg/100 g irrespective of amounts and kinds of carotenoids supplemented to the diets. 3. 3. Only keto and non-esterified carotenoids were detected in the eggs. 4. 4. Canthaxanthin was transferred into eggs but not β-carotene. Astaxanthin esters were converted largely to non-esterified astaxanthin and partly to doradexanthin. It was presumed that idoxanthin present in the eggs was derived from non-esterified astaxanthin in the diets.

Bioactive marine metabolites I. Isolation of guaiazulene from the gorgonianEuplexaura erecta

The isolation and identification of guaiazulene from the gorgonianEuplexaura erecta is described.