title: Synthesis of Novel Oxime Sulfonate Derivatives of 2'(2',6')-(Di)chloropicropodophyllotoxins as Insecticidal Agents.
abstract: To discover novel natural-product-based pesticidal agents, we prepared a series of oxime sulfonate derivatives of 2'(2',6')-(Di)chloropicropodophyllotoxins by structural modification of podophyllotoxin. Their structures were well-characterized by proton nuclear magnetic resonance ((1)H NMR), high-resolution mass spectrometry (HRMS), optical rotation, and melting point. Moreover, the key steric structure of compound 5f was unambiguously determined by single-crystal X-ray diffraction. Additionally, their insecticidal activity was evaluated at 1 mg/mL against the pre-third-instar larvae of oriental armyworm (Mythimna separata Walker), a typical lepidopteran pest. Among all derivatives, compounds 4c, 5c, and 5d exhibited more promising insecticidal activity, with the final mortality rates greater than 60%, when compared to their precursor podophyllotoxin and the positive control, toosendanin. It demonstrated that introduction of the chlorine atom at the C-2' or C-2',6' position on the E ring of picropodophyllotoxin or oxime sulfonate derivatives of picropodophyllotoxin was important for the insecticidal activity and introduction of a halogen (e.g., fluorine, chlorine, or bromine) atom-substituted phenylsulfonyl group on the oxime fragment of 2'(2',6')-(di)chloropicropodophyllones could lead to more promising compounds.
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhi
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
mesh_terms: D000818:Animals; D007306:Insecticides / Q000138:chemical synthesis* / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009036:Moths / Q000187:drug effects / Q000254:growth & development; D010091:Oximes / Q000737:chemistry*; D011034:Podophyllotoxin / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D007306:Insecticides; D010091:Oximes; D011034:Podophyllotoxin
keywords: Mythimna separata Walker; insecticidal activity; natural-product-based insecticide; oxime sulfonate; podophyllotoxin; structural modification