A new C22 polyacetylene and seven isoprenylated pterocarpans from Erythrina subumbrans.

A new C22 polyacetylene, erysectol A (1), and seven isoprenylated pterocarpans, phaseollin (2), phaseollidin (3), cristacarpin (4), (3'R)-erythribyssin D/(3'S)-erythribyssin D (5a/5b) and dolichina A/dolichina B (6a/6b) were isolated from the twigs and leaves of Erythrina subumbrans. Their structures were determined based on their NMR spectral data. Except for 2-4, all the other compounds were isolated from this plant for the first time. Erysectol A was the first reported C22 polyacetylene from plants. Polyacetylene was isolated from Erythrina plants for the first time.

Antibacterial Prenylated p-Hydroxybenzoic Acid Derivatives from Oberonia myosurus and Identification of Putative Prenyltransferases.

Twelve hitherto unknown tandem prenylated p-hydroxybenzoic acid derivatives, namely, oberoniamyosurusins A-L, together with five known derivatives, were isolated from an EtOH extract of the whole parts of the plant Oberonia myosurus. Compounds 10, 13, and 17 exhibited moderate inhibitory activity against Staphylococcus aureus subsp. aureus ATCC29213 with MIC50 values ranging from 7.6 to 23 µg/mL. To determine the biosynthetic pathway of this class of tandem prenyl-substituted compounds, the full-length transcriptome of O. myosurus was sequenced, yielding 19.09 Gb of clean data and 10 949 nonredundant sequences. Two isoforms of p-hydroxybenzoic acid prenyltransferases were annotated and functionally characterized as the enzymes that might be involved in the biosynthesis of nervogenic acid (13) in Pichia pastoris.