茄黄斑螟性信息素化学的结构签定(英文)

Sex Pheromone of Eggplant Borer, Leucinodes orbonalis Guenee

本文采用TLC、GC、微量臭氧化和GC-MS等分析方法,从茄黄斑螟雌蛾性腺体提取物中,分离和鉴定出性信息素反-11-十六碳烯醇乙酸酯(1a)。触角电位和田间试验证明,天然提取物和合成样品均有强烈的生物活性。

The eggplant borer, Leucinodes orbonalis Guenee (Lepidoptera: Pyralidae), is a seriouspest of eggplant in various regions of China. The control of this pest is troubled with thefact that the chemical insecticides do not penetrate into eggplant fruit where the pests stay.Thus the female sex pheromone identified and synthesized as follows might be a prosperctivecandidate for population monitoring or direct control. Full-grown larvae were collected from the field. After pupation and sexual separation,the females were put in screened cages. The glands were excised and soaked in n-heptanefor 6 hr after up to 90% of the moths raised their abdominal tips for calling during theperiod 22:00 to 23:00 of the second day after emerging, the extracts were combined, sealedand stored in a refrigerator for structure identification. Twenty female equivalence(FE) of the above extract were concentrated and dropped on-to a silica gel plate (0.2 mm thick). After developing with a 4:1 mixture of n-hexane andethyl ether, the plate was cut into five fractions and washed with acetone. The field test for five fractions from TLC separation of 20 FE were carried out. Wa-ter basin traps were used. The traps were placed 10～15 m apart at a height of ca 1.0 m infields of eggplant. Synthetic chemicals were applied to rubber septa as dispensers, withoutrenewal during the experiment. However the bait traps of virgin female moths were usedfor only 1～2 days. High bioactivity was shown by the fraction of R_f 0.6～0.8 correspon-ding to a long chain acetate (Tab 1) and the remaining fractions showed no notable acti-vity. GC-MS(EI) analysis of the active fraction from TLC separation on SE-54 capillarycolumn recorded a major peak at 17.82 min which possessed the following fragment ions, m/z:222 (M^+-CH_3COOH), 194(C_(14)H^+_(28)), 180(C_(13)H^+_(24)), 166(C_(12)H^+_(22)), 152(C_(11)H^+_(20)), 138(C_(10)-H^+_(18)), 124(C_9H^+_(16)), 110(C_8H^+_(14)), 96(C_7H^+_(12)), 82(C_6H^+_(10)), and 61(CH_3COOH_2^+). Thesedata indicated that the natural pheromone is a n-hexadecenyl acetate. To determine the location of the double bond, microozonolysis was carried uot.GC-MS (methane C1) of the ozonolysis product on PEG-20 M capillary column showed a major peak at 6.60 min with parent ion at m/z 229(MH^+) and less ion at m/z, 169(MH^+-CH_3COOH) and 151 (MH-CH_3COOH-H_2O). These data indicated that the ozonolysis pro-duct of pheromone was 11-acetoxyundecanal, and thus showed that the double bond ofthe pheromone is located at 11-position. The configuration of the double bond was examined by comparison of the GC retentiontime(R_l) of the natural pheromone with that of synthetic (E)-and (Z)-11-hexadecenylacetate(1a and 1b) R_l of the synthetic 1a and 1b on DEGS capillary column were16.66 min and 17.33 min respectively, while that of the natural pheromone was 16.66 min.Thus, E configuration was defined.Sythesis of 1a and 1b was carried out as follows:n-CH_3 (CH_2)_8C≡CCH_2OHa→HC≡C(CH_2)_9CH_2OHb→HC≡C(CH_2)_9CH_2OTH Pc→n-C_4H_9C=C(CH_2)_9CH_2OTHP →n-C_4H_9CH=CH(CH_2)_9CH_2OTHP→1 a e→n-C_4H_9CH=CH(CH_2)_9CH_2OTHP→1 ba) NaH/1, 2-EDA, b) DHP, H_3^+O, c) n-BuLi/BuBrd) Na/Liq NH_3, e) H_2, P-2Ni, f) AcOH-AcClThe synthetic 1 a contained E 98.3% with retention time(R_t) 16.66 min.V_(max): 1740(?C=O), 1240(C—O—C), 970(—C=C—)cm^(-1)。δH: 0.89 (3H, t, CH_3),1.28[20 H, br, (CH_2)_n], 1.97(3H, s, COCH_3), 1.80～2.16(4H, br, —CH_2—C=C—CH_2—), 3.93(2H, t, —CH_2O—C=O), 5.26(2H, m, —C=C—)ppm。m/z: 222(M^+—CH_3COOH), 61(CH_3COOH_2^+)。The synthetic 1 b contained Z 97.8% with R_t 17.33 min.V_(max): 1740(?C=O), 1240(C—O—C), 730 (—C=C—)cm^(-1)。δ_H: 0.90(3 H, t, —CH_3),1.29[20 H, br, —(CH_2)?—], 1.95(3 H, s, —COCH_3), 1.80～2.13(4 H, —CH_2—C=C—CH_2—), 3.94(2 H, t, —CH_2O —C=O), 5.24 (2 H, t, J=5 Hz, —C=C—)ppm。m/z:222(M^+-CH_3COOH), 61(CH_3COOH_2^+)。 In the electroantennagram (EAG) 'puff' test at all levels, the males responded much stronger to synthetic 1 a than to 1 b. for example, 1.2 and 0.3mV for 1 a and 1 b respec-tively at 10 μg, and 0.8 and 0.1 mV 100 ng. In field trapping, 1 a was found to be veryattractive to male moths, and more males were captured by traps baited with 300 to 500μg1 b than with six alive females in Tab 1. This result proved that 1 a is the main compon-ent of the eggplant borer sex pheromone.