| Autor: |
Hao, Nan, Qi, Yinyin, Zhao, Long, Liang, Shuangshuang, Sun, Wenjing, Zhang, Sunao, Tian, Xiangrong |
| Zdroj: |
Journal of Agricultural and Food Chemistry; March 2024, Vol. 72 Issue: 9 p4596-4609, 14p |
| Abstrakt: |
To discover new botanical products-based insecticide candidates, 14 triterpenoid saponins (1–14) including four new ones, obscurosides A-D (1–4), were isolated from Clematis obscuraMaxim as potential agrochemicals against Acyrthosiphon pisumHarris and Plutella xylostella(L.). Compounds 1–3were characterized by a rare ribose substitution at C-3, and 4was a bidesmoside glycosylated at the rare C-23 and C-28 positions of the oleanane aglycone. Compounds 10(median antifeeding concentration, AFC50= 1.10 mg/mL; half-lethal concentration, LC50= 1.21 mg/mL) and 13(AFC50= 1.09 mg/mL, LC50= 1.37 mg/mL) showed significant insecticidal activities against third larvae of P. xylostellaat 72 h. All saponins displayed antifeedant activities against A. pisumwith the deterrence index of 0.20–1.00 at 400 μg/mL. Compound 8showed optimal oral toxicity (LC50= 50.09 μg/mL) against A. pisum, followed by compounds 1, 5–7, 9, and 14(LC50= 90.21–179.25 μg/mL) at 72 h. The shrinkage of the cuticle and the destruction of intestinal structures of microvilli, nucleus, endoplasmic reticulum, and mitochondria were toxic symptoms of 8-treated A. pisum. The significantly declined Chitinase activity in 8-treated A. pisumwith an inhibition rate of 79.1% at LC70(70% lethal concentration) could be the main reason for its significant oral toxicities. Molecular docking revealed favorable affinities of compounds 1and 8with group I Chitinase OfChtI (Group I Chitinase from Ostrinia furnacalis) through conventional hydrogen bonds and alkey/π-alkey interactions by different patterns. These results will provide valuable information for the development of novel botanical pesticides for the management of insect pests, especially against A. pisum. |
| Databáze: |
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