- Flavonoids and stilbenes from armand pine
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Seven flavonoids and seven stilbenes were isolated from the heartwood of Pinus armandii Fr. var. mastersiana Hay. Among them, trans-3,5-dimethoxystilbene oxide is a new compound and 3-acetyloxy-5,7-dihydroxyflavanone is the first report of its occurrence
- Fang, Jim-Min,Su, Wen-Chiung,Cheng, Yu-Shia
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- ENDOGENEOUS PINE WOOD NEMATICIDAL SUBSTANCES IN PINES, PINUS MASSONIANA, P. STROBUS AND P. PALUSTRIS
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The presence of the repellents and nematicides to the pine wood nematode, Bursaphelenchus xylophilus, was found in the heartwood and bark of Pinus massoniana, P. strobus and P. palustris, which have a resistance to the pine wood nematode.The heartwood of P. massoniana contained a repellent, α-humulene and two nematicidal substances, pinosylvin monomethylether (PMS) and (-)-nortrachelogenin for the nematode.The bark of the pine contained two nematicides, methyl ferulate and (+)-pinoresinol.PMS, which showed the highest nematicidal activity (LD 50 was 4 ppm), was also contained in the heartwood of P. strobus and the heartwood and bark of P. palustris.The resistance of these pines to the pine wood nematode is considered to be attributed to the presence of these endogenously defending substances.Further, the relationship between the structure and the nematicidal activity was elucidated for PSM and methyl ferulate.Moreover, PSM showed little anti-acetylcholinesterase activity.
- Suga, Takayuki,Ohta, Shinji,Munesada, Kiyotaka,Ide, Nagatoshi,Kurokawa, Masako,et al.
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p. 1395 - 1402
(2007/10/02)
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- Synthesis and nematocidal activity of hydroxystilbenes
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Various (E)-hydroxystilbenes were synthesized from (E)/(Z) mixtures of methoxystilbenes through a new (Z)-(E) isomerization method followed by demethylation. The nematocidal activity appears when methoxystilbenes are demethylated to hydroxystilbenes. For this activity, a hydroxy group at the C-2 or C-3 position is necessary. Thus, 2-hydroxy-, 3-hydroxy-, 2,6-dihydroxy-, 3,4-dihydroxy-, 3,5-dihydroxy-, 2,2'-dihydroxy-, 3,3'-dihydroxy-, 3,4'dihydroxy-, 2-hydroxy-4-methoxy-, 5-hydroxy-2-methoxy-, 2-hydroxy-6-methoxy-, 6-allyloxy-2-hydroxy-, 3-hydroxy-5-methoxy-, and 5-allyloxy-3-hydroxystilbenes showed rather potent nematocidal activity. The activity of 5-allyloxy-3-hydroxystilbene was the strongest [minimal lethal concentration (MLC) = 30 μM]. The activities of the (E) and (Z) isomers were comparable. The activities were also retained, though they were weaker, in the dihydro derivatives, hydroxybibenzyls.
- Ali,Kondo,Tsuda
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p. 1130 - 1136
(2007/10/02)
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- PRENYL BIBENZYLS FROM THE LIVERWORT RADULA KOJANA
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Fourteen new bibenzyl derivatives have been isolated from the liverwort Radula kojana together with two previously known bis(bibenzyls) and their structures characterized by spectral and chemical evidence.Seven new bibenzyls, 3,5-dihydroxy-2-(3-methyl-2-b
- Asakawa, Yoshinori,Kondo, Keiko,Tori, Motoo,Hashimoto, Toshihiro,Ogawa, Shunichi
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p. 219 - 234
(2007/10/02)
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