Insecticidal Triterpenes in Meliaceae: Plant Species, Molecules, and Activities: Part II (Cipadessa, Melia)

Abstract

Plant-originated triterpenes are important insecticidal molecules. Research on the insecticidal activity of molecules from Meliaceae plants has always been a hotspot due to the molecules from this family showing a variety of insecticidal activities with diverse mechanisms of action. In this paper, we discussed 116 triterpenoid molecules with insecticidal activity from 22 plant species of five genera (Cipadessa, Entandrophragma, Guarea, Khaya, and Melia) in Meliaceae. In these genera, the insecticidal activities of plants from Entandrophragma and Melia have attracted substantial research attention in recent years. Specifically, the insecticidal activities of plants from Melia have been systemically studied for several decades. In total, the 116 insecticidal chemicals consisted of 34 ring-intact limonoids, 31 ring-seco limonoids, 48 rearranged limonoids, and 3 tetracyclic triterpenes. Furthermore, the 34 ring-intact limonoids included 29 trichilin-class chemicals, 3 azadirone-class chemicals, and 1 cedrelone-class and 1 havanensin-class limonoid. The 31 ring-seco limonoids consisted of 16 C-seco group chemicals, 8 B,D-seco group chemicals, 4 A,B-seco group chemicals, and 3 D-seco group chemicals. Furthermore, among the 48 rearranged limonoids, 46 were 2,30-linkage group chemicals and 2 were 10,11-linkage group chemicals. Specifically, the 46 chemicals belonging to the 2,30-linkage group could be subdivided into 24 mexicanolide-class chemicals and 22 phragmalin-class chemicals. Additionally, the three tetracyclic triterpenes were three protolimonoids. To sum up, 80 chemicals isolated from 19 plant species exhibited antifeedant activity toward 14 insect species; 18 chemicals isolated from 17 plant species exhibited poisonous activity toward 10 insect species; 16 chemicals isolated from 11 plant species possessed growth-regulatory activity toward 8 insect species. In particular, toosendanin was the most effective antifeedant and insect growth-regulatory agent. The antifeedant activity of toosendanin was significant. Owing to its high effect, toosendanin has been commercially applied. Three other molecules, 1,3-dicinnamoyl-11-hydroxymeliacarpin, 1-cinnamoyl-3-methacryl-11-hydroxymeliacarpin, and 1-cinnamoyl-3-acetyl-11-hydroxymeliacarpin, isolated from Meliaazedarach, exhibited a highly poisonous effect on Spodoptera littoralis; thus, they deserve further attention.

Macaronesian Plants as Promising Biopesticides against the Crop Pest Ceratitis capitata

“…Saponins are also known to negatively interfere with insect metabolism, namely by a cytotoxic action due to permeation of the cell membrane [ 38 ]. Finally, triterpenes, such as azadirachtin, which was used here as a positive control, are known for their insecticidal [ 39 , 40 ] and oviposition deterrent activities [ 41 ].…”

Limonoids from neem (Azadirachta indica A. Juss.) are potential anticancer drug candidates

“…PLGA nanoparticles of nimbolide as well as iRGD peptide (9-amino acid cyclic peptide CRGDKGPDC) conjugated nimbolide liposomes can hopefully increase bioavailability besides ensuring targeted delivery. 142,143 Azadirone (molecular formula: C 28 H 36 O 4 , molecular mass: 436.6), a limonoid isolated from neem flowers and seeds exhibits antifeedant, 144 antiplasmodial, 145 and antineoplastic activities. Using molecular docking simulation method, Ahammad et al, 148 retrieved and screened 70 phytochemicals from the neem tree against minichromosome maintenance complex component 7 (MCM7) protein, a replication protein overexpressed in several malignant tumors.…”

“…Azadirone (molecular formula: C 28 H 36 O 4 , molecular mass: 436.6), a limonoid isolated from neem flowers and seeds exhibits antifeedant, 144 antiplasmodial, 145 and antineoplastic activities 38,146 . Nanduri et al, 146 evaluated the in vitro cytotoxic activity of azadirone as well as its semisynthetic analogs against a panel of human cancer cell lines in vitro and in Swiss albino mice implanted with tumor cells using poly vinylidine fluoride hollow fibers in vivo.…”

Deciphering the key pathway for triterpenoid biosynthesis in Azadirachta indica A. Juss.: a comprehensive review of omics studies in nature’s pharmacy

“…The ability of Meliaceae plants to metabolize structurally diverse and physiologically relevant compounds is well established (Lin et al, 2022). The massive amount of literature available across several platforms makes it challenging to find information on each Neem metabolite.…”