Rediocides B−E, Potent Insecticides from Trigonostemon reidioides

Abstract

Four new congeners, rediocides B-E (2-5), of the previously reported rediocide A (1) were isolated from a methanol extract of the roots of the plant Trigonostemon reidioides. The structures of these minor analogues were elucidated by comparison of their NMR and mass spectral data with those of rediocide A and confirmed by extensive 2D NMR spectral analysis. They all possess potent activity against fleas (Ctenocephalides felis) in an artificial membrane feeding system and exhibited LD(90) values ranging from 0.25 to 0.5 ppm.

Antiviral chlorinated daphnane diterpenoid orthoesters from the bark and wood of Trigonostemon cherrieri

“…Numerous structurally interesting compounds such as flavonoidal alkaloids (Kanchanapoom et al, 2002), indole alkaloids (Tan et al, 2010;Zhu et al, 2010), phenanthrenes (Kokpol et al, 1990) and an array of daphnane-type diterpenoids (Chen et al, 2010a;Dong et al, 2011a;Jayasuriya et al, 2000Jayasuriya et al, , 2004Li et al, 2011;Lin et al, 2010;Soonthornchareonnon et al, 2005;Zhang et al, 2010a) have been isolated from this genus. Daphnane-type diterpenoids of Trigonostemon have been shown to possess insecticidal (Jayasuriya et al, 2000(Jayasuriya et al, , 2004, acaricidal (Soonthornchareonnon et al, 2005), cytotoxic (Chen et al, 2010b;Dong et al, 2011b;Lin et al, 2010) and antiviral (Zhang et al, 2010b) properties.…”

Chemical Constituents of Plants from the Genus Trigonostemon

“…isolated from this plant were evaluated for their insecticidal properties in an anti-flea artificial membrane feeding assay, exhibited LD 90 values of 0.25, 0.25, 0.5, 0.25, and 0.5 ppm, respectively. In comparison, ivermectin, paraherquamide, and nodulisporic acid A displayed LD 90 values of 10, > 100, and 1 ppm, respectively, in the [14] same assay [6]. Compound 1 also showed potent activity against mosquito larvae in an in vitro assay and exhibited an LD 90 value of 1 ppm [4].…”

A New Cytotoxic Daphnane Diterpenoid, Rediocide G, from Trigonostemon reidioides

“…6) Comparison of carbon multiplicities in the DEPT spectrum of rediocide A (1) and C (3) with rediocide G (7) revealed that rediocide G (7) possesses one less CH 3 and a CH group, and has two additional CH 2 groups, suggesting the presence of a cyclohexyl instead of methylcyclopentyl ring. The COSY spectrum showed the correlations between both H 2 -8Ј with H 2 -9Ј and H 2 -11Ј with H 2 -12Ј.…”