Studies on the probing stimulants for the white-backed planthopper, Sogatella furcifera (Homoptera: Delphacidae) in rice plant (Oryza sativa L.)

Abstract

To elucidate the probing stimulants in rice plants for the white-backed planthopper, Sogatella furcifera, bioassay-guided separations were conducted, which led to the isolation of four active compounds. Using NMR and LC-MS spectra, their structures were determined as isoorientin 2″-O-(6‴-(E)-feruloyl)glucoside, isoorientin 2″-O-(6‴-(E)-p-coumaroyl)glucoside, tricin 5-O-glucoside, and isoscoparin 2″-O-(6‴-(E)-feruloyl)glucoside.

A practicable strategy for enrichment and separation of four minor flavonoids including two isomers from barley seedlings by macroporous resin column chromatography, medium‐pressure LC, and high‐speed countercurrent chromatography

“…Compound 2 (isoscoparin 7‐o‐(6′′′‐feruloyl) glucoside): 1 H NMR (500 MHz， DMSO‐d6), δ : 7.52(1H, s, H‐2′), 7.48(1H, m, H‐6′), 7.44 (1H, d, J = 16.3 Hz, feruloyl H‐7),7.10(1H, s, feruloyl H‐2), 7.06(1H, s, H‐3), 6.91(1H, s, H‐8), 6.85(1H, d, J = 8.2 Hz, H‐5′), 6.81 (1H, d, J = 8.2 Hz, feruloyl H‐6), 6.74 (1H, d, J = 7.9 Hz, feruloyl H‐5), 6.42 (1H, d, J = 15.9 Hz, feruloyl H‐8), 5.11(1H, d, J = 7.0 Hz, 7‐ O ‐glc‐H‐1), 4.73(1H, d, J = 9.8 Hz, 6‐ C ‐glc‐H‐1), 3.67(3H, s, feruloyl OMe), 3.87(3H, s, 3′‐OCH 3 ). 13 C NMR (125 MHz，DMSO‐d6), δ: 182.47 (C‐4), 167.08 (feruloyl ‐COOR), 166.97 (C‐2), 162.67 (C‐7), 159.83 (C‐5), 156.83 (C‐9), 149.97 (C‐4′), 148.63 (feruloyl C‐3), 148.23 (C‐3′, feruloyl C‐4), 145.99 (feruloyl C‐7), 125.58 (feruloyl C‐1), 123.31 (feruloyl C‐6), 123.18 (C‐6′), 121.02 (C‐1′), 116.31 (C‐5′), 115.79 (feruloyl C‐5), 114.20 (feruloyl C‐8), 111.46 (feruloyl C‐2), 110.55 (C‐6), 111.00 (C‐2′), 105.34 (C‐10), 101.22 (C‐1′′′), 100.84 (C‐3), 94.04 (C‐8), 81.21 (C‐5′′), 79.29 (C‐3′′), 76.27 (C‐2′′), 76.08 (C‐3′′′), 74.12 (C‐2′′′), 73.09 (C‐5′′′), 71.30 (C‐1′′), 70.49 (C‐4′′), 69.80 (C‐4′′′), 63.84 (C‐6′′′), 60.72 (C‐6′′), 56.35(3′‐OCH 3 ), 55.90 (feruloyl ‐OCH 3 ) .…”

Chemical Structure Diversity and Extensive Biological Functions of Specialized Metabolites in Rice

“…The expression of genes involved in terpenoid synthesis is usually elevated following herbivory, and high concentrations of terpenoids are synthesized to resist biological stress. For example, when the rice phloem is subjected to herbivory by Sogatella furcifera, a mixture of volatile sesquiterpenoids is obtained from the damaged parts (Table 1) [144][145][146]. These volatile sesquiterpenoids include (E)-γ-bisabolene (28) and α-zingiberene (31), which are some of the products of the sesquiterpene synthases encoded by the Os08g07100 and Os08g04500 genes.…”