Insect Antifeedants from Tropical Plants II:  Structure of Zumsin

Abstract

A novel A-seco limonoid was isolated from methanolic extract of Croton jatrophoides and designated as zumsin. This compound showed potent antifeedant activity against two lepidopteran larvae, pink bollworm, Pectinophora gossypiella (PC(50) = 1 microg/cm(2), PC(95) = 8 microg/cm(2)), and fall armyworm, Spodoptera frugiperda (PC(50) = 2 microg/cm(2), PC(95) = 16 microg/cm(2)). The structure of zumsin was determined as 1 using a variety of spectroscopic methods including nuclear magnetic resonance, mass spectrometry, and circular dichroism. The structure consists of an A'-B trans-fused ring while dumsin (2), a constituent of the same source, maintains an A'-B cis-fused ring, and suggests two unique biosynthetic processes after A ring oxidative expansion.

Insect Antifeedants from Croton jatrophoides: Structures of Zumketol, Zumsenin, and Zumsenol

“…Compound 1 showed potent activities with PC 50 ) 0.5 µg/mL and PC 90 ) 2 µg/mL against P. gossypiella, and PC 50 ) 3 µg/mL and PC 90 ) 16 µg/mL against S. frugiperda, which were similar to that of previously reported limonoids of the same type. 2 To investigate more details of the structure-activity relationships and the biogenetic pathway of the limonoids, additional research is suggested using C. jatrophoides as an interesting plant source.…”

A novel limonoid from the seeds of Chisocheton siamensis

“…Epoxidation at C-14/15 of mohinin (4) gave 6α-acetoxyepoxyazadiradione (6). In the case of epoxyazadiradione (5) 13 C, and DEPT spectral data of chisosiamensin (1) and nimonol (7). rived from the epoxidation at C-14/15 of azadiradione (3) (Scheme 1).…”

“…A number of limonoids have been isolated from several genera of Meliaceae and some of these exhibit antimalarial (1,2), cytotoxic (3,4), antiprotozoal (5), and antifeedant (6,7) activities. Chisocheton siamensis is one of the Meliaceae plants, which is found in the northern part of Thailand.…”

Synthesis of Limonoid Natural Products

“…[62] Dumsin (131) contains a compact and highly oxygenated central core comprising nine stereogenic centers, four of which are quaternary carbon atoms. [63] The molecules differ in the nature of the ring fusion across the B/C sector. [63] The molecules differ in the nature of the ring fusion across the B/C sector.…”

“…The isolation and structure determination of a structurally related limonoid, zumsin (132), was later reported. [63] The molecules differ in the nature of the ring fusion across the B/C sector. Additional variation between 131 and 132 includes the position of the A-ring carbonyl functionality as well as the lack of a western C19 hemiketal (of an α-diketone) in zumsin.…”