title: Paralytic toxicity in the ribbon worm Cephalothrix species (Nemertea) in Hiroshima Bay, Hiroshima Prefecture, Japan and the isolation of tetrodotoxin as a main component of its toxins.
abstract: Paralytic toxicity of ribbon worms ("himomushi" in Japanese), identified as undescribed species of the genus Cephalothrix, found on the surface of the shells of cultured oysters in Hiroshima Bay, Hiroshima Prefecture was examined between April 1998 and December 2001. The toxicity study showed that all of specimens were found to contain toxins with strong paralytic action in mice; the highest toxicity (as tetrodotoxin, TTX) was 25,590 mouse units (MU) per gram for whole body throughout the monitoring period. The main toxic component of this himomushi toxin (HMT) was isolated from a pooled specimen (390 g; total toxicity 2,897,000MU) by a method that consisted of treatment with activated charcoal, chromatography on Bio-Gel P-2 and Bio-Rex 70 (H+ form), and finally crystallization from an acidified methanolic solution. The recrystallized toxin showed a specific toxicity of 3520MU/mg. This toxin showed (M+H)+ and (M+H-H(2)O)+ ion peaks at m/z 320 and 302, respectively, by electrospray ionization-mass spectrometry (ESI-MS). The absorption band at 3353, 3235, 1666, 1612 and 1076 cm(-1) were observed in infrared spectrum of this toxin. This spectrum was indistinguishable from that of TTX. The 1H-NMR spectrum for the recrystallized toxin was the same as that for TTX. The pair of doublets centered at 2.33 (J=10.0Hz) and 5.48 ppm (J=10.0Hz) which are characteristic of TTX, were shown to be coupled by double irradiation. Furthermore, by gas chromatography-mass spectrometry (GC-MS) of the alkali-hydrolyzate of this toxin indicated the presence of quinazoline skeleton (C9-base) specific to TTX.
authors.affiliation: Department of Bioresource Science and Technology, Graduate School of Biosphere Sciences, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan. asakawa@ipc.hiroshima-u.ac.jp
authors.forename: Manabu
authors.initials: M
authors.lastname: Asakawa
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Toyoshima
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Ito
authors.forename: Kentaro
authors.initials: K
authors.lastname: Bessho
authors.forename: Chisato
authors.initials: C
authors.lastname: Yamaguchi
authors.forename: Shogo
authors.initials: S
authors.lastname: Tsunetsugu
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Shida
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kajihara
authors.forename: Shunsuke F
authors.initials: SF
authors.lastname: Mawatari
authors.forename: Tamao
authors.initials: T
authors.lastname: Noguchi
authors.forename: Keisuke
authors.initials: K
authors.lastname: Miyazawa
mesh_terms: D000818:Animals; D008401:Gas Chromatography-Mass Spectrometry; D007448:Invertebrates; D007564:Japan; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008387:Marine Toxins / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity*; D051379:Mice; D010125:Ostreidae; D010243:Paralysis / Q000139:chemically induced; D012621:Seasons; D012623:Seawater; D013559:Symbiosis; D013779:Tetrodotoxin / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity
chemical_list: D008387:Marine Toxins; D013779:Tetrodotoxin