Shari L. Lupien

Cytochrome P450 Limonene Hydroxylases of Mentha Species

The oxygenation pattern of the monoterpenoids of mint (Mentha) species is determined by regiospecific cytochrome P450-catalyzed hydroxylation of the common olefinic precursor (-)-limonene. In peppermint, C3-allylic hydroxylation leads to (-)-trans-isopiperitenol that ultimately is converted to (-)-menthol, whereas in spearmint, C6-allylic hydroxylation leads to (-)-trans-carveol that is oxidized to (-)-carvone. The limonene-6-hydroxylase and the cytochrome P450 reductase were purified from the oil glands of spearmint, and the system was reconstituted. Amino acid sequences from the purified hydroxylase were utilized to design primers with which a large, non-degenerate PCR product was prepared. This probe was employed to screen a spearmint oil gland cDNA library from which the corresponding full-length cDNA was isolated. This clone provides the tool for isolating the homologous cDNA species from peppermint and related Mentha species.

Neocosmospora sp.-derived resorcylic acid lactones with in vitro binding affinity for human opioid and cannabinoid receptors.

Bioassay-guided fractionation of a fungus Neocosmospora sp. (UM-031509) resulted in the isolation of three new resorcylic acid lactones, neocosmosin A (2), neocosmosin B (3), and neocosmosin C (4). Three known resorcylic acid lactones, monocillin IV (1), monocillin II (5), and radicicol (6), were also isolated and identified. The structures of these compounds were established on the basis of extensive 1D and 2D NMR spectroscopic analysis, mass spectrometric (ESIMS) data, and X-ray crystallography. Compounds 4-6 show good binding affinity for the human opioid receptors. These findings have important implications for evaluating the potential psychoactive effects with this class of compounds.

Ascochyta blight of chickpea reduced 38% by application of Aureobasidium pullulans (anamorphic Dothioraceae, Dothideales) to post-harvest debris

Abstract In 2004–2005, application of non-amended suspensions of Aureobasidium pullulans conidia to post-harvest chickpea debris resulted in 37.9% fewer Ascochyta blight lesions on chickpea test plants relative to controls. Analogous tests in 2006–2007 resulted in 38.4% fewer lesions. Ascospores released from debris were predominantly Davidiella sp. (anamorph, Cladosporium sp.), followed by Didymella rabiei (anamorph, Ascochyta rabiei, agent of Ascochyta blight).