Ann T. McKenzie

Goniothalenol: a novel, bioactive, tetrahydrofurano-2-pyrone from Goniothalamus giganteus (Annonaceae)

Abstract Fractionation of the stem bark of the title plant, monitoring for bioactivity with brine lethality, led to the isolation of goniothalenol (I). Mass, 1HNMR, and 13CNMR spectral data helped to characterized I as a phenyltetrahydrofurano-2-pyrone, as a novel heterocyclic ring system for natural compounds. X-Ray crystallographic analysis confirmed the structure and established the configuration for I.

Novel 6,7-seco-6,11-cyclolabdane diterpenes from cluytia richardiana

Abstract Two novel 6,7-seco-6,11-cyclolabdane diterpenoids, richardianidin-1 and 2, were isolated from the leaves of Cluytia richardiana L. The structure and stereochemistry of 1 and 2 were established to be 6- (acetyloxy)-15,16-epoxy-2,12-dihydroxy-6,7-seco-6,11-cyclolabda-8,13(16),14-triene-7,18-dioic acid γ-lactone δ-lactone and 6-(acetyloxy)-15,16-epoxy-1,12-dihydroxy-6,7-seco-6,11-cyclolabda-8,13(16),14-triene-7,18-dioic acid di-δ-lactone based on spectroscopy and X-ray data.

PHOTODIMERIZATION OF 1,3‐DIMETHYL‐5‐CHLOROURACIL*

Abstract— 1,3‐Dimethyl‐5‐chlorouracil dimerizes upon direct photolysis in aqueous solution to give one major photodimer. X‐Ray analysis has been used to identify the dimer as the anti head‐to‐tail isomer, IV.