Natural Product-Based Drugs Discovery: Semisynthesis and Biological Evaluation of Ester Derivatives from Pregn-5-ene-3 beta,17a,20(S)-triol

There is no doubt that derivation of intermediates from natural product is a very efficient way to develop new environmentally friendly pesticide. We synthesis a succession of compounds esterified with pregn-5-ene-3 beta,17 alpha,20(S)-triol to evaluate its insecticidal and bacteriostatic activity. Otherwise, their structure-activity relationships (SAR) are also discussed. As a result, compounds 7g, 7h, 7j, 7l and 7o exhibit more obvious insecticidal activity against 3rd Mythimna separata Walker (LC50 = 0.60, 0.68, 0.79, 0.85 and 0.78 mg/mL, respectively) than periplocoside F (PSF). Meanwhile, compounds 7g, 7h and 7i perform well inhibitory activity against Pseudomas syringae pv. actinidiae (Psa) in vitro (minimum inhibitory concentra-tion (MIC) values: 0.10-0.25 mg/mL, minimum bactericidal concentration (MBC) values: 0.15-0.35 mg/mL). And SAR analysis indicates that the replacement and position of fluorine atom on benzoyl are highly vital to biological activity.