Feeding deterrents from Aconitum episcopale roots against the red flour beetle, Tribolium castaneum

Development of an ultra-high-performance liquid chromatography-tandem mass spectrometry method for the simultaneous determination of crassicauline A, fuziline, karacoline, and songorine in rat plasma and application in their pharmacokinetics

In this paper, an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for quantifying the levels of crassicauline A, fuziline, karacoline, and songorine in rat plasma. After processing the rat plasma, the proteins in the plasma were separated by extracting the analytes with acetonitrile-methanol (9:1, v/v). The chromatographic column used was the UPLC HSS T3 column, and the mobile phase (methanol-water with 0.1% formic acid) under a gradient elution profile was used to separate the four compounds, with elution times for each analyte being less than 5 min. Electrospray ionization in positive-ion mode and operating in multiple reaction monitoring mode was used for quantitative analysis. Crassicauline A, fuziline, karacoline, and songorine were administered to 48 rats (n = 6 per group) orally (5 mg/kg) and intravenously (0.5 mg/kg). The standard curves demonstrated excellent linearity in the range of 1-2500 ng/mL, wherein all r values were greater than 0.99. The UPLC-MS/MS method for the determination of crassicauline A, fuziline, karacoline, and songorine in rat plasma was successfully applied in determining their pharmacokinetics parameters, from which their oral bioavailabilities were calculated to be 18.7%, 4.3%, 6.0%, and 8.4%, respectively.

Detection of Specific Volatile Organic Compounds in Tribolium castaneum (Herbst) by Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry

The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is a major storage pest that could lead to a wide range of damage. Its secretions have a significant impact on the quality of stored grain and food, leading to serious food safety problems such as grain spoilage and food carcinogenesis. This study investigates new detection techniques for grain storage pests to improve grain insect detection in China. The primary volatile organic chemicals (VOCs) in these secretions are identified using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The specific VOCs that are unique to T. castaneum are selected as criteria for determining the presence of T. castaneum in the granary. To obtain more specific VOCs, experiments were designed for the analysis of T. castaneum samples under different extraction times, two types of SPME fibers and two GC-MS devices of different manufacturers. The experimental results showed that 12 VOCs were detected at relatively high levels, seven of which were common and which were not detected in other grains and grain insects. The seven compounds are 1-pentadecene, 2-methyl-p-benzoquinone, 2-ethyl-p-benzoquinone, 1-hexadecene, cis-9-tetradecen-1-ol, m-cresol and paeonol. These seven compounds can be used as volatile markers to identify the presence of T. castaneum, which could serve as a research foundation for the creation of new techniques for T. castaneum monitoring.

Insecticidal potential of extracts, fractions, and molecules of Aconitum heterophyllum Wall ex. Royle against aphid Aphis craccivora Koch (Hemiptera: Aphididae)

BACKGROUND

Aphis craccivora is the major sap-sucking pest of leguminous crops and vector of plant viruses that cause damage to plants and reduce yield. Indiscriminate and nonjudicious use of synthetic insecticides led to resistance development and harmful to environment. Therefore, it is important to discover plant-based lead(s) which can replace synthetic insecticides. In the current study the residual toxicity of extracts, fractions, and isolated compounds of Aconitum heterophyllum were evaluated against A. craccivora to identify lead(s) for further development of botanical formulation.

RESULTS

In residual contact assay, ethanolic (LC₅₀  = 2837.17 mg L^-1 ) and aqueous methanolic extracts (LC₅₀  = 2971.59 mg L^-1 ) were effective against A. craccivora. Among fractions, the n-butanol fraction of the aqueous methanolic extract (LC₅₀  = 986.96 mg L^-1 ) was found to be most effective, followed by the ethyl acetate fraction of the ethanolic extract (LC₅₀  = 1037.52 mg L^-1 ) and the n-hexane fraction of both extracts (LC₅₀  = 1113.85 to 1233.11 mg L^-1 ). Among pure molecules, aconitic acid was found to be the most effective (68% mortality; LC₅₀  = 1313.19 mg L^-1 ) and was on a par with azadirachtin 0.15% EC (66% mortality; LC₅₀  = 1921.10 mg L^-1 ). Furthermore, from the effect of ethanoic extract on detoxification enzyme inhibition in A. craccivora we concluded that the target site of action of this extract in A. craccivora might be glutathione S-transferase.

CONCLUSIONS

The parent extract/fractions of A. heterophylum showed promising activity against A. craccivora. Among phytoconstituents of the active extract and fractions, aconitic acid was found to be on a par with azadirachtin 0.15% EC. © 2022 Society of Chemical Industry.

A review: Pharmacokinetics and pharmacology of aminoalcohol-diterpenoid alkaloids from Aconitum species

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum medicinal materials, such as Aconitum carmichaelii Debeaux (Chinese: Wutou/) and Aconitum kusnezoffii Reichb. (Chinese: Caowu/), are a kind of important Traditional Chinese Medicine (TCM) with great medicinal value. Statistics show that there are over 600 efficient TCM formulations comprising Aconitum medicinal materials. But high toxicity limits their clinical application. Clinically, the Aconitum medicinal materials must undergo a complex processing process that includes soaking, steaming, and boiling with pharmaceutical excipients, which makes highly toxic ester diterpenoid alkaloids are hydrolyzed to form less toxic aminoalcohol-diterpenoid alkaloids (ADAs).

AIM OF THE STUDY

This review aims to summarize the pharmacokinetic and pharmacological activities of low-toxicity ADAs, providing a reference for future ADAs research and drug development.

MATERIALS AND METHODS

Accessible literature on ADAs published between 1984 and 2022 were screened and obtained from available electronic databases such as PubMed, Web of Science, Springer, Science Direct and Google Scholar, followed by systematic analysis.

RESULTS

ADAs are secondary products of plant metabolism, widely distributed in the Aconitum species and Delphinium species. The toxicity of ADAs as pharmacodynamic components of Aconitum medicinal materials is much lower than that of other diterpenoid alkaloids due to the absence of ester bonds. On the one hand, the pharmacokinetics of ADAs have received little attention compared to other toxic alkaloids. The research primarily focuses on aconine and mesaconine. According to existing studies, ADAs absorption in the gastrointestinal tract is primarily passive with a short T_max. Simultaneously, efflux transporters have less impact on ADAs absorption than non-ADAs. After entering the body, ADAs are widely distributed in the heart, liver, lungs, and kidney, but less in the brain. Notably, aconine is not well metabolized by liver microsomes. Aconine and mesaconine are excreted in urine and feces, respectively. ADAs, on the other hand, have been shown to have a variety of pharmacological activities, including cardiac, analgesic, anti-inflammatory, anti-tumor, antioxidant, and regenerative effects via regulating multiple signaling pathways, including Nrf2/ARE, PERK/eIF2α/ATF4/Chop, ERK/CREB, NF-κB, Bcl-2/Bax, and GSK3β/β-catenin signaling pathways.

CONCLUSIONS

ADAs have been shown to have beneficial effects on heart disease, neurological disease, and other systemic diseases. Moreover, ADAs have low toxicity and a wide range of safe doses. All of these suggest that ADAs have great potential for drug development.

Diterpenoid alkaloids from Aconitum barbatum var. puberulum Ledeb

Seven previously undescribed diterpenoid alkaloids, including five C₂₀-diterpenoid alkaloids, barpuberudine, barpubesines A-D, and two C₁₈-diterpenoid alkaloids, barpubenines A-B, along with 11 known diterpenoid alkaloids were isolated from the whole plant of Aconitum barbatum var. puberulum Ledeb. (Ranunculaceae). Barpuberudine is an unprecedented carbon skeleton of C₂₀-diterpenoid alkaloid, while barpubenines A-B are the first example of rearranged types in C₁₈-diterpenoid alkaloids. Their structures were elucidated based on a comprehensive spectroscopic data analysis. The probable pathway of biogenesis of barpuberudine and barpubenines A-B were discussed. Additionally, the antiarrhythmic, cytotoxic and antimicrobial activities of isolates were also evaluated.

Norditerpenoid alkaloids from Delphinium pseudoaemulans C. Y. Yang et B. Wang

Eight previously undescribed norditerpenoid alkaloids, pseudophnines A-D, pseudorenines A-B, and pseudonidines A-B, together with ten known norditerpenoid alkaloids, tianshanisine E, sharwuphinine B, potanisine A, lycoctonine, delbruline, isondelpheline, delavaines A-B, and shawurenines A-B were isolated from the whole plant of Delphinium pseudoaemulans C. Y. Yang et B. Wang. Their structures were established on the basis of spectroscopic analyses, including HR-ESI-MS, 1D and 2D NMR analysis. Additionally, no cytotoxicity was observed against A549 and HeLa cancer cells of these diterpenoid alkaloids when evaluated in vitro using the MTT method.

Diterpenoid Alkaloids from Two Aconitum Species with Antifeedant Activity against Spodoptera exigua

Twenty-five diterpenoid alkaloids were isolated from the roots of two Aconitum species. The structures of seven new C₁₉-diterpenoid alkaloids, apetaldines A-G (1-7), and 10 known alkaloids (8-17) from Aconitum apetalum and eight known alkaloids (18-25) from Aconitum franchetii var. villosulum were elucidated via HRESIMS, IR, and NMR data. Alkaloids 1-10, 15, 16, and 18-25 were screened for their antifeedant activity. Among the compounds tested, chasmanthinine (19) showed highly potent antifeedant activity with an effective concentration for 50% feeding reduction (EC₅₀) at 0.07 mg/cm². The antifeedant structure-activity relationship of the diterpenoid alkaloids is also discussed.

Chemical Constituents of Supercritical Extracts from Alpinia officinarum and the Feeding Deterrent Activity against Tribolium castaneum

Alpinia officinarum has been confirmed to possess bioactivities against some pests. In this work, a sample was obtained from A. officinarum rhizomes by supercritical fluid CO₂ extraction (SFE). According to GC-MS analysis, the main chemical components for SFE-sample included benzylacetone (26.77%), 1,7-diphenyl-5-hydroxy-3-heptanone (17.78%), guaiacylacetone (10.03%) and benzenepropanal (7.42%). The essential oil of A. officinarum rhizomes (LD₅₀ = 20.71 μg/adult) exhibited more contact toxicity than SFE extract (LD₅₀ = 82.72 μg/adult) against Tribolium castaneum. From SFE extracts, one new compound, 1-phenyl-4-(16,17-dimethyl-9,13-octadiene)-5-isopentenyl-7-(4"-methoxyl-3"-hydroxyl-phenyl)-3-heptanone (3), together with five known compounds identified as 5-hydroxy-1,7-diphenyl-3-heptanone (1), 1,7-diphenyl-4-hepten-3-one (2), galangin (4), galangin-3-methyl ether (5) and pinocembrin (6), were isolated and their feeding deterrent activities against T. castaneum adults were assessed. It was found that compounds 1-6 had feeding deterrent activities against T. castaneum with feeding deterrent indices of 18.21%, 18.94%, 19.79%, 26.99%, 20.34%, and 35.81%, respectively, at the concentration of 1500 ppm. Hence, the essential oil and SFE extracts/compounds of A. officinarum rhizomes represent promising alternatives in the control of T. castaneum adults.

Diterpenoid Alkaloids from Aconitum soongaricum var. pubescens

One new diterpenoid alkaloid, pubescensine (1), along with nine known diterpenoid alkaloids (2–10) were isolated from the roots of Aconitum soongaricum var. pubescens. Their structures were elucidated by spectroscopic analyses and comparison with previously reported data. All the compounds were evaluated for their antifeedant activities. The aconitine-type diterpenoid alkaloids (1–6) showed considerably potent antifeedant activity (EC50 < 1 mg/cm2), while the activities of napelline-type diterpenoid alkaloids (compds. 7, 9 and 10) were not significant (EC50 > 50 mg/cm2).

Diterpene alkaloids with an aza-ent-kaurane skeleton from Isodon rubescens

Two compounds belonging to a new group of diterpene alkaloids, kaurines A and B (1 and 2), and an alkaloid bearing a succinimide moiety (3) were obtained from Isodon rubescens. Their structures and absolute configurations were determined by spectroscopy and quantum-chemical computational (13)C NMR and ECD data analysis. These alkaloids differ from known diterpene alkaloids and diterpenoids and are presumably biosynthesized from ent-kaurane diterpenoids.

Review of advances in the thin layer chromatography of pesticides: 2010-2012

Techniques and applications of thin layer chromatography (planar chromatography) for the separation, detection, qualitative and quantitative determination, and preparative isolation of pesticides and their metabolites and some related pollutants are reviewed for the period from November 1, 2010 to November 1, 2012. Analyses are described for a variety of samples types and pesticide classes. In addition to references on residue analysis, studies such as pesticide structure - retention relationships, identification and characterization of natural and synthesized pesticides, metabolism, degradation, mobility, lipophilicity, and mechanism of action are covered.