An empirically derived correlation of configuration and nmr chemical shifts for diastereomeric mandelate, O-methylmandelate and a-methoxy-a-trifluoromethylphenylacetate (MTPA) esters has been developed and rationalized in terms of useful models 4 and 5. These models have been successfully applied to well over 40 examples as given in Table I. The correlations involve the relative chemical shifts of the proton resonances from the groups attached to the carbinyl carbon of these diastereomeric esters. This nmr-configurational correlation should prove to be widely applicable in assigning the configuration of additional secondary carbinols, as well as other chiral -substituted carboxylic acid derivatives.(1) We gratefully acknowledge a grant in support of this study by the National Science Foundation (NSF GP 27448).(2) Taken from the Ph.D. thesis of J.

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In literature and alchemy the salamander is a fabled creature. Salamanders have long been known to be toxic animals, the poisons they produce usually being associated with secretions of specialized glands or of the skin itself. An extraordinarily powerful neurotoxin, called tarichatoxin, has recently been isolated in crystalline form from the eggs of various species of western American newts of the genus Taricha. This toxin, present in adult newts as well as in newt eggs and embryos, is very different chemically and pharmacologically from other known salamander toxins. This makes all the more remarkable the finding, in recent work, that tarichatoxin is identical to a toxin known as tetrodotoxin which occurs in the Japanese Fugu or puffer fish. The substance appears to occur only in one family of Amphibia (the Salamandridae) and one suborder of fishes (the Tetraodontoidae). This extremely limited distribution is a remarkable biogenetic finding.Here we discuss the course of the investigations which led to the isolation of the toxin from the California newt, the history of tetrodotoxin, the evidence, both physical and physiological, which points to the conclusion that tarichatoxin and tetrodotoxin are one and the same substance, and the deductions which can be made concerning the chemical structure of the toxin. Tarichatoxin Discovery and history. In the early 1930's Victor C. Twitty, an experimental embryologist, came to Stanford University from Yale. At New Haven he had worked with the eastern salamander, Ambystoma punctatum, and at 1100 Dr. Mosher is professor of chemistry, Dr. Fuhrman is professor of experimental medicine, and Drs. Buchwald and Fischer are research associates in chemistry at

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