Antimicrobial and Antiinsectan Phenolic Metabolites of Dalea searlsiae

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• 作者：Gil Belofsky ; Mario Aronica ; Eric Foss ; Jane Diamond ; Felipe Santana ; Jacob Darley ; Patrick F. Dowd ; Christina M. Coleman ; Daneel Ferreira
• 刊名：Journal of Natural Products
• 出版年：2014
• 出版时间：May 23, 2014
• 年：2014
• 卷：77
• 期：5
• 页码：1140-1149
• 全文大小：310K
• 年卷期：v.77,no.5(May 23, 2014)
• ISSN：1520-6025

文摘

Continued interest in the chemistry of Dalea spp. led to investigation of Dalea searlsiae, a plant native to areas of the western United States. Methanol extractions of D. searlsiae roots and subsequent chromatographic fractionation afforded the new prenylated and geranylated flavanones malheurans A鈥揇 (1鈥?b>4) and known flavanones (5 and 6). Known rotenoids (7 and 8) and isoflavones (9 and 10) were isolated from aerial portions. Structure determination of pure compounds was accomplished primarily by extensive 1D- and 2D-NMR spectroscopy. The absolute configurations of compounds 1鈥?b>5, 7, and 8 were assigned using electronic circular dichroism spectroscopy. Antimicrobial bioassays revealed significant activity concentrated in the plant roots. Compounds 1鈥?b>6 exhibited MICs of 2鈥? 渭g/mL against Streptococcus mutans, Bacillus cereus, and oxacillin-sensitive and -resistant Staphylococcus aureus. Aerial metabolites 7鈥?b>10 were inactive against these organisms, but the presence of 7 and 8 prompted investigation of the antiinsectan activity of D. searlsiae metabolites toward the major crop pest Spodoptera frugiperda (fall armyworm). While compounds 1鈥?b>10 all caused significant reductions in larval growth rates, associated mortality (33鈥?6%) was highest with flavanone 4 and rotenoids 7 and 8. These findings suggest a differential allocation of antimicrobial and antiinsectan plant resources to root and aerial portions of the plant, respectively.