Lynamicin B is a Potential Pesticide by Acting as a Lepidoptera-Exclusive Chitinase Inhibitor.

Insect group h chitinase is a promising target for designing non-target safe pesticides in that it is exclusively distributed in lepidopteran insects, over 80% of which are agricultural pests. In this work, lynamicin B was discovered to be an inhibitor of Chi-h, the group h chitinase from the lepidopteran pest . Lynamicin B was revealed to competitively inhibit Chi-h with a value of 8.76 μM and does not significantly inhibit other chitinases. The co-crystal structure of lynamicin B and Chi-h revealed that the dichloroindolyl group of lynamicin B occupies an unexplored pocket below subsites +1 and +2 of the substrate-binding cleft, which is vital for its selectivity. Feeding experiments demonstrated that lynamicin B exhibited high insecticidal activities against other lepidopteran pests and besides . Moreover, lynamicin B did not affect , a natural enemy of . This study provides a natural-derived potent pesticide for the control of lepidopteran pests, leaving its natural enemy unaffected.