Date of Award

Spring 1991

Document Type


Degree Name

Master of Science (MS)


Chemistry & Biochemistry



Committee Director

Roy L. Williams

Committee Member

Charles E. Bell

Committee Member

Mark S. Elliott

Call Number for Print

Special Collections LD4331.C45T35


Opsanus tau (Linnaeus), the Oyster toadfish, commonly inhabits the Chesapeake Bay. The Oyster toadfish has been categorized as a venomous and/or ichthyotoxic fish; however, chemical studies to substantiate these claims have not been forthcoming.

The oyster toadfish has dorsal and opercular spines which are believed to secrete a venom(s). Based on our findings, the oyster toadfish does not secrete venom(s) from these spines.

The oyster toadfish secretes large amounts of a mucus when it is irritated. 3-Octanone was believed to be the major ichthyotoxic component of the mucus from the oyster toadfish. Based on our investigation, 3-octanone is present only when the fish mucus is extracted with n-butanol and then concentrated.

The untreated mucus, however, does not contain 3-octanone. The 3-octanone in the mucus is presumably a degradation or experimental by-product from some unknown source. This research has attempted to determine the possible precursor(s) to the 3-octanone. A possible precursor, Optoxin, (4-Acetoxy Choline 4-Oxononanoate chloride), was hypothesized based on the existing data related to another mucus toxin, Pahutoxin, This toxin was isolated from the mucus of Hawaiian Boxfish, a distant relative to the oyster toadfish. The attempted synthesis of optoxin and degradation studies of optoxin are described herein.

Another important aspect of the research project involved the extraction of viscous material(s) from the axillary and opercular glands of Opsanus tau. Both glands appear to produce high molecular weight proteins which have been designated as Optausin I and II respectively. The two specific proteins have been characterized as having molecular weights of 100,000 and 83,000 daltons. The two Optausins appear to be identical by Infrared spectra analysis and have shown some interesting biological activities. The Optausins inhibit the growth of Staphylococcus aureus and suppress the human lymphocyte response at microgram level.


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