Eudistomins C, E, K, and L, potent antiviral compounds containing a novel oxathiazepine ring from the Caribbean tunicate Eudistoma olivaceum

Abstract

Of the 650 marine species assayed during the 1978 Alpha Helix Caribbean Expedition (AHCE 1978)3 the colonial tunicate Eudistoma olivaceum4 was the most active against Herpes simplex virus, type 1 (HSV-1). In the present report we assign structures 1, 2, 5, and 6 (Table I), containing the previously unreported condensed oxathiazepine ring system, to eudistomins C, E, K, and L, respectively, which include the most active antiviral components of E. olivaceum. In the following communication5 *we assign the structures of eudistomins A, D, G, , I, J, , N, O, P, and Q, additional bioactive components isolated from E. olivaceum.The methanol-toluene (3:1) extract3 of E. olivaceum (IRCE l-VII-81-3-1, IFE 21-V-82-1-3) was partitioned with toluene and water. The toluene phase yielded eudistomins G, H, and I (see following communication),5 while extraction of the aqueous phase with chloroform yielded an oil, which was subjected to C18 reversed-phase medium-pressure liquid chromatography (MPLC) with methanol-water (7:3) then to silica gel MPLC

Interspecific differences in fouling of two congeneric ascidians (Eudistoma olivaceum and E. capsulatum): is surface acidity an effective defense?

“…Rinehart et al (1984) noted that "Of the 650 marine species assayed during the 1978 Alpha Helix Caribbean Experiment •.. Eudistoma olivaceum was the most active against Herpes simplex virus, type 1 (HSV type 1)". Twenty eudistomins have been isolated from this ascidian species (Kinzer andCardellina 1987, Rinehart et al 1987).…”

Search for New Bioactive Marine Natural Products and Application to Drug Development

“…24,25) Iejimalide A is also expected to be a promising lead compound for a novel type of antiosteoporosis agent, since V-ATPase inhibitors trigger apoptotic cell death of osteoclasts. 24,25) Eudistomin C, a β-carboline alkaloid isolated from a Caribbean compound tunicate Eudistoma olivaseum, displayed extremely potent antiviral activity against DNA and RNA viruses 26,27) (Fig. 9).…”

Antiviral agents - some current developments

“…Further reports on this interesting class of compounds are anticipated. A more recent study describes the isolation, from the Caribbean tunicate Eudistoma olivaceum, of another class of compounds containing the hitherto unreported condensed oxathiazepine ring system, two of which were potent vitro inhibitors of HSV-1 (17).…”