Insecticidal activity of isolated phenylpropanoids from Alpinia galanga rhizomes against Spodoptera litura

Abstract

Botanical insecticides as a means of controlling insects present an alternative approach that is safer than the use of synthetic insecticides. The present study identified the insecticidal activity of extracts of the rhizomes of Alpinia galanga (L.) Willd. and seven isolated phenylpropanoids against the second instar of Spodoptera litura Fab. by topical application.The ethyl acetate extract had the highest toxicity on this insect with LD 50 values of 1.68 and 1.25 μg/larva after 24 and 48 h posttreatment, respectively. Among the seven phenylpropanoids separated from the ethyl acetate extract, 1'S-1'-acetoxychavicol acetate was identified as the most active compound with LD 50 values of 1.63 and 1.40 g/larva after 24 and 48 h posttreatment, respectively, followed by p-coumaryl diacetate. In addition, the two active compounds decreased glutathione S-transferase activity and increased acetylcholinesterase activity. p-Coumaryl diacetate also decreased carboxylesterase activity.

Stability Study of Alpinia galanga Constituents and Investigation of Their Membrane Permeability by ChemGPS-NP and the Parallel Artificial Membrane Permeability Assay

“…The resonances at δ 171.2 (C-4′-OAc) and 20.9 (C-4′-OAc) ppm in the 13 C NMR spectrum and δ 2.26 (s, 3H, H-4′-OAc) ppm in the 1 H NMR spectrum revealed the presence of an additional acetyl group; therefore, the compound was identified as trans-p-acetoxycinnamyl alcohol. The 1 H and 13 C NMR resonances were analogous to data in the literature [32].…”

Insecticidal and growth inhibitory effects of some thymol derivatives on the beet armyworm,Spodoptera exigua(Lepidoptera: Noctuidae) and their impact on detoxification enzymes

“…It was indicated that GST is an important factor in acquiring resistance to insecticides, especially in crop pests, which can modify the target‐site protein or enhance enzymatic detoxification 43 . The carboxylesterase and GST inhibition by thymyl butanoate is not an exception; 1′ S ‐1′‐acetoxychavicol acetate, isolated from Alpinia galanga , did decrease carboxylesterase activity in Spodoptera exigua 12 and GST activity in Spodoptera litura 13 . However, both postulates require detailed biochemical investigation to establish site‐specific activity.…”

“…Secondary metabolites from plants that belong to significant groups of alkaloids, phenolics, sterols, steroids, flavonoids, tannins, anthocyanins, lignins, terpenes, etc., are known to control insect pests in many ways and are predominantly safe compared to chemical pesticides 9,10 . For instance, some recent studies using the crude extracts and isolated compounds obtained from Bauhinia scandens , 11 Alpinia galanga , 12,13 and Piper retrofractum 14 have been reported as very effective against Plutella xylostella , Spodoptera exigua , and Spodoptera litura . Similarly, monoterpenes like thymol, 1,8‐cineole, linalool, pulegone, methyl eugenol, trans ‐anethole, carvacrol, and α ‐terpineol were toxic to insects 7 ; especially thymol has been reported as very effective insecticidal compound against several insect pests 15–18 …”

Quantitative Study on Anti-Pest Activity of Natural Products Based on Visualization Framework of Knowledge Graph

“…The LC50 after 24 and 48 h of treatment were 1.63 and 1.40 μg per larva, respectively. These two active compounds decreased glutathione S-transferase activity and increased the acetylcholinesterase activity [121] . Lycoriella ingenua and Coboldia fuscipes are two of the most economically important insect pests of cultivated mushrooms.…”