Isolation of rice weevil feeding inhibitors uncinatone and pectolinarigenin from Clerodendron siphonenthus

Evaluation of fractions and 5,7-dihydroxy-4',6-dimethoxy-flavone fromClerodendrum phlomidis Linn. F. against Helicoverpa armigera Hub.

“…Similarly, pinocembrin isolated from Flourensia oolepis having hydroxyl groups at 7 th position in A-ring and carbonyl at 4 th position in pyran ring C were responsible for the highest antifeedant activity against Epilachna paenulata (Georgina et al 2009). Pectolinaringenin isolated from Clerodendron siphonenthus by Pal et al (1989) showed feeding inhibition against the rice weevil, Sitophilus oryzae and from C. phlomidis by Muthu et al (2013) showed ovicidal and oviposition deterrent activities against E. vittella, which also confirmed the present findings.…”

Do elevated atmospheric CO2 and O3 affect food quality and performance of folivorous insects on silver birch?

“…Although elevated O 3 resulted in accelerated leaf senescence (Vapaavuori et al , 2009), which can lead general decline of host quality (Hellmann, 2002), PLS analysis revealed that several phenolic compounds contributed to the decreased growth of E. autumnata (Table 2). Apigenin derivative 3 (identified as pectolinarigenin by Peltonen et al , 2006), a common flavonoid aglycone present on the birch leaf surface, has shown antifeedant activity against insects (Pal et al , 1989; Thoison et al , 2004). Flavonoid aglycones (Lahtinen et al , 2004) also decrease preference and performance of first instar E. autumnata larvae, although the actual postingestive mechanism is still unclear.…”

Bioefficacy of pectolinaringenin from Clerodendrum phlomidis Linn. F. against Anopheles stephensi and bhendi fruit borer, Earias vittella fab.

“…Medeiros et al (1994) reported that keto group at C-4 in quercetin, karanjin, chrysoeriol and butein showed strong antifeedant activity and the presence of 7-hydroxyl group in the flavone was responsible for the highest antifeedant activity against Mythmina unipuncta (Haworth, 1809). Pectolinaringenin isolated from Clerodendron siphonenthus was screened against Sitophilus oryzae (Linnaeus, 1763) by Pal et al (1989) and reported that the compound inhibited the feeding. Kaemperol and quercetin flavonoids having an oxidised C-ring, inhibited feeding in Scolytus multistriatus (Marsham, 1802) (Norris 1970).…”