Yoshiro Hashimoto

Toxicity of the zoanthid Palythoa tuberculosa

Abstract Histological examination combined with toxicity tests revealed that the toxicity of a zoanthid Palythoa tuberculosa Esper is essentially defined by the presence of eggs in a polyp. The marked variation of its toxicity as reported previously could be assigned to the uneven distribution of female polyps in a colony and their seasonal appearance. In addition, some evidence for protogynous hermaphroditism is presented. The reproductive cycle of polyps and diagnostic characters of the eggs and testes are described.

Separation of grammistins A, B and C from a soapfish Pogonoperca punctata

Abstract Grammistin from a soapfish, Pogonoperca punctata, was fractionated into its components by using countercurrent distribution and Sephadex LH-20 column chromatography. Three components, designated as grammistins A, B and C, were obtained in the pure state as judged by thin layer chromatography. They were different from each other in both hemolytic activity and amino acid composition. These components are peculiar polypeptides having an unknown moiety positive to the Dragendorff reagent.

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.

Isolation of two toxins from a parrotfish Scarus gibbus

Abstract E. Chungue , R. Bagnis , N. Fusetani and Y. Hashimoto . Isolation of two toxins from a parrotfish Scarus gibbus. Toxicon 15, 89–93, 1977.—Clinical and epidemiological observations suggested that at least two toxins are involved in poisoning from ingestion of the parrotfish Scarus gibbus . In the present study, the parrotfish flesh collected from the Gambier Islands was extracted by the method adopted for extraction of ciguatoxin and the crude toxin obtained was fractionated by column chromatography using silicic acid and DEAE-cellulose. Two fat-soluble toxins were separated by DEAE-cellulose column chromatography. The polar one was very similar to ciguatoxin and the other different from ciguatoxin. The latter toxin (SG-1) was further purified by repeated gel filtration on Sephadex LH-20 to give an oily substance with a lethality to mice of 0·03 mg per kg. It showed some similarity to ciguatoxin in biological and chemical properties, but an apparent dissimilarity in chromatographic behavior. The significance of this toxin in the ciguatera phenomenon is briefly discussed.

GRAMMISTIN, THE SKIN TOXIN OF SOAPFISHES, AND ITS SIGNIFICANCE IN THE CLASSIFICATION OF THE GRAMMISTIDAE

GRAMMISTIN, THE SKIN TOXIN OF SOAPFISHES, AND ITS SIGNIFICANCE IN THE CLASSIFICATION OF THE GRAMMISTIDAE Author(s) Randall, John E.; Aida, Katsumi; Hibiya, Takashi; Mitsuura, Nobuhiro; Kamiya, Hisao; Hashimoto, Yoshiro Citation PUBLICATIONS OF THE SETO MARINE BIOLOGICAL LABORATORY (1971), 19(2-3): 157-190 Issue Date 1971-10-30 URL http://hdl.handle.net/2433/175661 Right Type Departmental Bulletin Paper Textversion publisher

Occurrence of a skin toxin in coral-gobies Gobiodon spp.

Abstract Coral-gobies Gobiodon spp. contain a skin toxin having a stinging and bitter taste, ichthyotoxicity and hemolytic activity. The skin possessed peculiar secretory cells assumed to secrete the toxin. When the whole fish or epidermis was stored without preheating, the toxin disappeared rapidly, probably due to enzymatic degradation. The toxin of Gobiodon quinquestrigatus was obtained from the epidermis by extraction with ethanol and purified by precipitation at 25 per cent saturation of NaCl, countercurrent distribution, and Sephadex LH-20 column chromatography. In thin layer chromatography the final preparation still gave three spots, each positive to Dragendorff reagent, ninhydrin, and each having hemolytic activity. The toxin was easily dialyzable through a cellophane membrane and showed an absorption band at around 260 nm. The amino acid composition was very similar to that of the 1-butanolic extract from the mucus of a soapfish Pogonoperca punctata and the toxin was assumed like grammistin to be a mixture of peptides containing a tertiary or quaternary amine moiety.

Occurrence of a crinotoxin and hemagglutinin in the skin mucus of the moray eel Lycodontis nudivomer

The tropical Indo-Pacific moray eel Lycodontis nudivomer possesses a mucous skin secretion which shows hemolytic, toxic and hemagglutinating activities. The active components were extracted from the mucous secretion with 0.02 M phosphate buffer (pH 7.5) and purified by DEAE-cellulose and Sephadex G-200 column chromatography. The component(s) responsible for the hemolytic-toxic activities differ(s) from that (those) causing the hemagglutinating activity. The hemolysin was unstable in the presence of heat, acidic and alkaline media, and several organic solvents. It was undialyzable throught a cellophane membrane, and showed an absorption maxium at 280 nm in the phosphate buffer (pH 7.5). The hemolytic activity was completely lost when treated with trypsin, indicating that the hemolysin is a protein. Histochemical examination on the epidermis of L. nudivomer revealed the presence of clubbed peculiar cells, in addition to common mucous cells, which we speculate produced the hemolytic-toxic component(s). Eight other species of morays were found to possess clubbed peculiar cells similar to those of L. nudivomer in their epidermis. There are marked differences, however, in the abundance of these cells among these muraenids.

The structure of nereistoxin.

When treated with Raney nickel, S-bisbenzoyl derivative of dihydronereistoxin gave N,N-dimethylisopropylamine together with dimethylamine. Supported by other evidences, especially on the presence of 1,2-dithiolane ring, this led us to postulate that nereistoxin is 4-N,N-dimethylamino-1,2-dithiolane. The structure was also unequivocally supported by the NMR spectrum. Some additional data on chemical property of nereistoxin and its derivatives were described in succession to the previous paper.

Occurrence of a tetrodotoxin-like substance in a goby Gobius criniger

Abstract The goby of the Ryukyus which is suspected of being poisonous was identified as Gobius criniger and demonstrated to possess a potent neurotoxin, which appears similar to tetrodotoxin. The toxin was soluble in water, easily dialyzable through a cellophane membrane, and unstable to heat at pH 10. By using activated charcoal and Amberlite IRC-50, a partially purified toxin having a lethality of 0·22 μg per g mouse was obtained. In thin-layer chromatography, this preparation gave a spot coinciding with that of crystalline tetrodotoxin. Symptoms in mice were similar to those induced by tetrodotoxin and saxitoxin. The dosedeath time curve in mice was identical with that for tetrodotoxin. It was also confirmed that both a puffer and G. criniger were neither killed nor paralyzed by an extraordinarily large dose of tetrodotoxin or goby toxin.

A new toxic crab, Atergatis floridus

Abstract A screening test for toxicrabs was carried out on 722 specimens of 56 species collected in the Ryukyu Islands and Amami Islands and a new toxic species, Atergatis floridus, was identified. Specimens of this species caught along the coast of the mainland of Japan were also found to be poisonous. Some specimens were nearly as toxic as specimens of Zosimus aeneus. Both species, A. floridus and Z. aeneus, showed a similar distribution of the toxin in their bodies; the appendages were more toxic than the cephalothorax and the exoskeleton was also found to contain a considerable amount of the toxin. The toxins from both species were similar in their chromatographic behavior and dose-death time curves in mice.