A new phenylpropane-pimarane heterodimer and a new ent-kaurene diterpene from the husks of Oryza sativa

Publication date: April 2018 Source:Phytochemistry Letters, Volume 24 Author(s): Qiang Zhang, Qiao-Lin Xu, Xiao-Mei Xia, Li-Mei Dong, Bi Luo, Wen-Bin Liu, Jian-Wen Tan A new phenylpropane-pimarane heterodimer, 2-[(E)-3-(4-hydroxy-3-methoxyphenyl) allylidene] momilactone A (1), and a new ent-kaurene diterpene, ent-3α,16α-dihydroxy-kauran-19-oic acid (2), were isolated from the rice husks of Oryza sative L., along with a known ent-kaurene diterpenoid ent-7-oxo-kaur-15-en-19-oic acid (3). Their structures were determined by spectroscopic means, including nuclear magnetic resonance (NMR) and mass spectrometry (MS) techniques. Compound 3 was isolated as a natural product for the first time. These compounds were tested for their in vitro antifungal activity against rice pathogenic fungi Magnaporthe grisea and Rhizoctonia solani. Compounds 1 and 3 were found to show anti-fungal activity against M. grisea and R. solani with MIC values ranging from 6.25 to 25 μg/mL. No inhibitory activity was detected for compound 2 in this bioassay. Graphical abstract

Source: Phytochemistry Letters - March 21, 2018 Category: Chemistry Source Type: research