Antiherbivore Prenylated Benzoic Acid Derivatives from Piper kelleyi

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• 作者：Christopher S. Jeffrey ; Michael D. Leonard ; Andrea E. Glassmire ; Craig D. Dodson ; Lora A. Richards ; Massuo J. Kato ; Lee A. Dyer
• 刊名：Journal of Natural Products
• 出版年：2014
• 出版时间：January 24, 2014
• 年：2014
• 卷：77
• 期：1
• 页码：148-153
• 全文大小：331K
• ISSN：1520-6025

文摘

The known prenylated benzoic acid derivative 3-geranyl-4-hydroxy-5-(3鈥?3鈥?dimethylallyl)benzoic acid (1) and two new chromane natural products were isolated from the methanolic extract of the leaves of Piper kelleyi Tepe (Piperaceae), a midcanopy tropical shrub that grows in lower montane rain forests in Ecuador and Peru. Structure determination using 1D and 2D NMR analysis led to the structure of the chromene 2 and to the reassignment of the structure of cumanensic acid as 4, an isomeric chromene previously isolated from Piper gaudichaudianum. The structure and relative configuration of new chromane 3 was determined using 1D and 2D NMR spectroscopic analysis and was found to be racemic by ECD spectropolarimetry. The biological activity of 1鈥?b>3 was evaluated against a lab colony of the generalist caterpillar Spodoptera exigua (Noctuidae), and low concentrations of 2 and 3 were found to significantly reduce fitness. Further consideration of the biosynthetic relationship of the three compounds led to the proposal that 1 is converted to 2 via an oxidative process, whereas 3 is produced through hetero-[4+2] dimerization of a quinone methide derived from the chromene 2.