The ambrosia beetle, Xyleborinus saxesenii Ratzeburg, infests physiologically stressed apple and peach trees in Korea. Dispersing females utilize the degradation product ethanol and host-related volatiles to locate and colonize new host trees. We examined the extent to which 12 chemicals emitted from fruit trees act synergistically with ethanol to attract X. saxesenii. The addition of benzaldehyde to ethanol significantly increased beetle attraction, although benzaldehyde was not attractive by itself. The addition of α-pinene, ethyl butyrate, ethyl isovalerate, limonene, 3-methyl-1-butanol, ethyl tiglate, aromadendrene, vanillin, 2-butanol, styrene, or ethyl 3,3-dimethylacrylate to ethanol had no effect on beetle attraction. In a dose-response test, the addition of 5–50% benzaldehyde doses synergistically increased the number of beetle captures; however, trap catches did not increase as the benzaldehyde dosage increased. The synergistic influence of benzaldehyde on beetle response to ethanol was lower in early spring than in late summer to early fall, probably because synthetic benzaldehyde emissions from field lures were overwhelmed by background levels of natural benzaldehyde emitted from peach twigs in the flowering stage.

Background : Amomum tsao-ko (Zingiberaceae) is widely distributed among several countries in Asia. It’s dried fruit is widely used in Korea for medical plant, China and Japan for the treatment of dyspepsia, eliminates, vomiting, abdominal pain, phlegm, warms the spleen, and malaria. In this study, we describe the structural determination of the new compounds and the inhibitory activities of isolated compounds against LPS-induced NO production in RAW264.7 cells. Methods and Results : The fruits of A. tsao-ko were extracted with 80% EtOH two times at room temperature. The EtOH extract was suspended in distilled water and partitioned with solvent to give CH2Cl2, EtOAc and n-BuOH. The CH2Cl2 was suspended in n-hexane and partitioned with solvent to give 50%, 70% and 90% MeOH. The purification of each fraction by column chromatography separation and HPLC analysis. Consequently, one new benzaldehyde (1) and two new cycloterpenals (2 and 3) along with five known compounds (4 –8) have been isolated from the fruits of A. tsao-ko. The structure and relative stereochemistry were determined from HRMS, 1D and extensive 2D NMR techniques as well as by comparison of their data with the published values. Conclusion : These compounds were identified as Amotsaokonal A (1), Amotsaokonal B (2), Amotsaokonal C (3), methyl linolenate (4), trans-nerolidol (5), (2E)-dodecenyl acetate (6), (2E)-dodecenyl acetate (7), and pyrrole-2-carboxylic acid (8). All isolates were tested for their inhibitory activities on LPS-induced nitric oxide production in RAW264.7 cells.