Influence of Pyranose and Spacer Arm Structures on Phloem Mobility and Insecticidal Activity of New Tralopyril Derivatives.

Six new conjugates were designed and synthesized by introducing glucose, methyl glucuronate or glucuronic acid moieties on tralopyril. Phytotoxicity and phloem mobility results demonstrated that the introduction of glucose, methyl glucuronate or glucuronic acid moieties can simultaneously solve the tough phytotoxicity problem and phloem mobility transformation of tralopyril. Conjugates and containing the glucuronic acid moiety exhibited higher phloem mobility than conjugates , , and . Conjugates , and with methoxymethyl groups on the tralopyril pyrrole nitrogen atom showed activity against , while conjugates , and with a methene group on the pyrrole N showed no activity. Cabbage roots were incubated in a buffered solution containing conjugates , and at 4 mM for 72 h. Only showed systemic insecticidal activity with 100% mortalityagainst while and showed lower activity andchlorfenapyr showed no activity. The glucuronic acid promoiety imparted more phloem mobility to tralopyril than glucose and methyl glucuronate. The methoxymethyl group bond on the tralopyril skeleton was the key factor in determining the insecticidal activity of the conjugates. A promising systemic proinsecticide containing glucuronic acid and tralopyril moieties was proposed.