Pesticidal character of phytoecdysteroids from Ajuga multiflora Bunge (Labiatae) on larvae of Cryptorrhynchus lapathi L. (Coleoptera: Curculionidae)

Eight kinds of phytoecdysteroids extracted from different parts of Ajuga multiflora Bunge (Labiatae) that were collected from different places at different time were tested for killing effects on the 2-instar larvae of Cryptorrhynchus lapathi L by adding them to the artificial diet of larvae. The experimental results indicated that adding 1-3-mL phytoecdysteroids to the artificial diet could lead 58%-100% of 2-instar larvae of C. lapathi to death within 24 days. The phytoecdysteroids extracted from the whole plant of A. multiflora which was collected before flowering time were much more effective than those extracted from the plants collected at flowering and after flowering periods, and the modified mortality rate of larvae reached 65.22%, 85.07%, and 98.11% at the dosage level of 1-mL, 2-mL, and 3-mL extracts, respectively. The extract made from root of A. multiflora plant was more effective in killing efficiency than those from stem and leaves, and the average death rates of larvae were up to 100%, 98.20% and 98.32% at dosage levels of 1-mL, 2-mL, and 3-mL extracts, respectively. The killing speed of the extracted phytoecdysteroids was slower than that of triflumuron, hexaflumuron or deltamethrin emulsifiable concentrate. The mortality rate of larvae is closely related to the feeding duration on the diets containing phytoecdysteroids. Feeding on the diets with addition of phytoecdysteroids for 16 days, more than 80% of treated 2-instar larvae of C. lapathi were led to death. The killing effect of the extracts was little affected by the growth areas of A. multiflora plant and the adding way to artificial diet.

Phytoecdysteroids from <i>Silene praemixta</i>

The waste products of the production of ecdysterone (3) from Silene praemixta M. Pop. (Caryophyllaceae) were investigated. The column chromatography of the technological waste has allowed to isolating 2-de- soxyecdysone (1), 2-deoxyecdysterone (2), ecdysterone (3) and 22-O-β-D-glucopyranoside of 2-deoxyecdy- sone (4). Glucoside 4 was found for the first time in the plant Silene praemixta. Ecdysteroids 1, 2 prevailed in the sum. Compounds 3 and 4 were minor components of the waste products. The identification of com- pounds 1-4 was carried out by using the modern me- thods of 1D and 2D NMR spectroscopy: 1H, 13C, DEPT, 1H-1H COSY, HSQC, NOESY, IR spectroscopy and ESI MS.

The phytochemical, biological, and medicinal attributes of phytoecdysteroids: An updated review

The phytoecdysteroids(PEs)comprise a large group of biologically-active plant steroids,which have structures similar to those of insect-molting hormones.PEs are distributed in plants as secondary metabolites that offer protection against phytophagus(plant-eating)insects.When insects consume the plants containing these chemicals,they promptly molt and undergo metabolic destruction;the insects eventually die.Chemically,ecdysteroids are a group of polyhydroxylated ketosteroids that are structurally similar to androgens.The carbon skeleton of ecdysteroids is termed as cyclopentanoperhydro-phenanthrene with aβ-side chain at carbon-17.The essential characteristics of ecdysteroids are a cis-(5β-H)junction of rings A and B,a 7-en-6-one chromophore,and a trans(14α-OH)junction of rings C and D.Plants only synthesize PEs from mevalonic acid in the mevalonate pathway of the plant cell using acetyl-CoA as a precursor;the most common PE is 20-hydroxyecdysone.So far,over 400 PEs have been identified and reported,and a compilation of 166 PEs originating from 1998 has been previously reviewed.In the present review,we have summarized 212 new PEs reported between 1999 and 2019.We have also critically analyzed the biological,pharmacological,and medicinal properties of PEs to understand the full impact of these phytoconstituents in health and disease.

Deep chemical identification of phytoecdysteroids in Achyranthes bidentata Blume by UHPLC coupled with linear ion trap-Orbitrap mass spectrometry and targeted isolation

Achyranthes bidentata Blume is widely used as a traditional Chinese medicine with the effects of nourishing the liver and kidneys and strengthening muscles and bones.In this work,a rapid and simple strategy was developed for characterizing phytoecdysteroids by ultra-high-performance liquid chromatography coupled with liner ion trap-Orbitrap mass spectrometry using electrospray ionization in the negative mode.As a result,47 phytoecdysteroids were unambiguously or tentatively characterized.Among them,seven known compounds were identified according to the reference standards along with molecular formula,retention time and fragmentation patterns,while others were mostly potential new compounds.Through targeted isolation,the structures of three new compounds were determined by NMR spectra,which were consistent with LC-MS characterization.The present study provides an efficient method to deeply characterize phytoecdysteroids.

Control Ability of Extracts from Ajuga Plants on Some Pests

Several phytoecdysteroids have been found in the extracts of A. multiflora and A.linearifolia using HPLC analysis. Those were 20-OH ecdysone, cyasterone, 3-acetate-20-OH ecdysone, 2-acetate-20-OH ecdysone, qugalactone. We found out that those phytoecdysteroids could lead the second instar larva of Clostera anastomosis and Stipnotia candida to death. The modified mortality rate was from 44.64% to 96.24%. Those extracts could signiticantly reduce the amount of nymph produced by the female Tuberolachnus salignus, The number of the nymph produced after treating with those extracts was only 20% to 70% of that produced by the untreated group. The death rate of the newly produced nymph which treated was among 33.33% to 58.82%. It was much higher than the death rate of the control group (1l7.57%).