Piercing sucking pests are destructive to many strategic crops all over the world. Botanical pesticides can be used to control these pests. A new withanolide derivative 3 named sominone A ((20R,22R)-1α,3β,20,27-tetrahydroxywitha-5,24-dienolide) was isolated from the alkaloid fraction of the whole plant of Withania somnifera. In addition, there are three known compounds named withasomine 1, methyl isoferulate 2, and coagulin Q 4 were also isolated. The structures of isolated compounds were identified using different spectroscopic methods such as 1D, 2D NMR, and HRESIMS spectroscopy. The alkaloid fraction and the four isolated compounds were tested for their pesticidal activity against four piercing sucking pests (Aphis craccivora Koch, Bemisia tabaci Gennadius, Nezara viridula Linnaeus, and Tetranychus urticae Koch) that attack many strategic crops under laboratory conditions, along with azadirachtin (Okios 3.2% EC) as a positive control. The results showed that the alkaloid compound (withasomine 1) was the most toxic to A. craccivora, B. tabaci, N. viridula, and T. urticae, with LC₅₀ values of 15.44, 36.61, 85.11, and 128.28 ppm, respectively, compared with the control. Withanolide compounds had moderate effects on all tested pests. Biochemical parameters of six enzymes; α-esterase, β-esterase, chitinase, acetylcholinesterase, glutathione-S-transferase, and peroxidase of A. craccivora were estimated at the LC₅₀ value of the most potent compound, withasomine 1 and the values were 38.83, 72.86, 31.45, 506.4, 2.62, and 251.0, respectively. The results demonstrated that all enzymes activity levels were increased compared with the control except a remarkable inhibition in AChE enzyme level was observed compared with control. Therefore, the alkaloid fraction of W. somnifera is a promising extract that contains many active compounds that can be used as a natural pesticide against many harmful pests in agriculture crops. Graphical Abstract

Four solvent fractions were obtained by successive extraction of Ipomoea carnea aerial parts. Five polyphenols were isolated and identified by spectroscopic methods from the ethyl acetate (EA) fraction named tiliroside (2) and from butanol (Bu) fraction named, apigenin-7β-O-glycoside (3), 3,5- di-O-caffeoylquinic acid (4) and two stereoisomers of 3,4- di-O-caffeoylquinic acid (5, 6) in addition to scopoletin (1) from methylene chloride (MC) fraction. GC/MS analysis of petroleum ether (PT) and MC fractions showed thirty-three compounds as well as, thirteen alkaloids were identified by using UPLC-ESI/MS/MS from alkaloid sub fraction (AK-sF) of MC. Insecticidal potentials of different fractions and the pure isolated compounds were evaluated for the first time on Aphis craccivora and Bemisia tabaci. The obtained results indicated that alkaloid subfraction was the most potent against the two insects. Biochemical investigations of different six enzymes elucidated mode of action of the most potent fraction. Antioxidant activity of I. carnea fractions and pure compounds was performed against DPPH radical. The present study clarified that caffeoylquinic acid (4-6) are mostly responsible for the antioxidant activity of I. carnea Bu fraction while the strong insecticidal activity of MC fraction was due to the ergoline alkaloids found in its AK-sF.

Piercing-sucking pests infest many strategic crops worldwide, causing significant damage to crops. Botanical natural products provide several promising pesticide agents that could control these pests as an alternative to the negatively impacted synthetic insecticides. Bioassay-guided separation of the alkaloid fraction of Quassia amara Linn. woody parts against two serious pests (Aphis craccivora Koch and Tetranychus urticae Koch) and resulted in the isolation of a new alkaloid, a β-carboline derivative 3 named quassianine, along with two known alkaloid compounds named harmine 1 and gardnerine 2 were isolated for the first time from this species using extensive chromatographic techniques. The structure elucidation of the isolated compounds was established via various 1D and 2D NMR and ESI–MS analyses. The susceptibility of both tested pests was assessed under laboratory conditions for the alkaloid and non-alkaloid fractions of Q. amara, the three pure isolated compounds and the positive control azadirachtin (Okios 3.2% EC). The alkaloid fraction was found to be the most potent fraction against A. craccivora and T. urticae with LC₅₀ values of 4.3 and 79.1 ppm, while harmine 1 was the most potent isolated compound with LC₅₀ values of 3.7 and 20.3 ppm, respectively. The most toxic alkaloid fraction and harmine compound were formulated and tested against both pests under field conditions using the LC₉₀ multiplicities. Furthermore, the biochemical parameters of six enzymes belonging to A. craccivora and T. urticae were estimated after the application of the LC₅₀ value of the alkaloid fraction and harmine 1. Also, a detailed toxicological study on the non-target organisms, honeybees Apis cerana, coccinellid predator ladybird beetles Coccinella septempunctata and adult albino rats was conducted. Several biochemical investigations (including alanine amino transaminase, albumin, total cholesterol and reproductive hormones), as well as histopathological studies were performed. The results showed that the alkaloid fraction contains many active principles that could serve as a natural pesticide to protect some agricultural crops from many serious pests and are safer than synthetic pesticides for non-target organisms. Therefore, the Q. amara alkaloid fraction may be considered a prototype natural pesticide. Graphical