No abstract

Using an ethnobotanical approach in combination with in vivo-guided fractionation as a means for lead discovery, cryptolepine was isolated as an antihyperglycemic component of Cryptolepis sanguinolenta. Two syntheses of cryptolepine, including an unambiguous synthesis, are reported. The hydroiodide, hydrochloride, and hydrotrifluoromethanesulfonate (hydrotriflate) salts of cryptolepine were synthesized, and a comparison of their spectral properties and their in vitro activities in a 3T3-L1 glucose transport assay is made. Cryptolepine and its salt forms lower blood glucose in rodent models of type II diabetes. While a number of bioactivities have been reported for cryptolepine, this is the first report that cryptolepine possesses antihyperglycemic properties.

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The tunicates, or sea squirts, are common marine organisms that selectively accumulate metals such as V, Fe, Mo, Nb, in their blood cells. Despite the more than 70 years of interest in the compounds responsible for this accumulation, their extreme lability has eluded attempts to isolate and characterize them. The isolation and structure of the first of these blood pigments tunichrome B-1 from the Ascidia nigra is reported.

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