Anti-trypanosomal cadinanes synthesized by transannular cyclization of the natural sesquiterpene lactone nobilin

Isolation and evaluation of trypanocidal activity of sesquiterpenoids, flavonoids, and lignans in Artemisia sieversiana collected in Mongolia

Artemisia sieversiana is an annual herbaceous plant distributed throughout Central and East Eurasia and is regarded as an undesirable forage plant in Mongolia. It affects livestock, so information about its chemical composition is needed. We isolated three new sesquiterpenoids (1-3) and known compounds from A. sieversiana and investigated their activities. The absolute configuration of 1 was established using single-crystal X-ray diffraction crystallography, and its configuration differed from those of reported compounds with similar structures. Two additional new sesquiterpenoids (2 and 3) with similar structures were identified, and their configurations were determined. The trypanocidal activities of the isolated compounds (1-18) against Trypanosoma congolense and the pathogen responsible for fatal trypanosomosis in animals were estimated. Flavonoids and lignans were identified as active compounds with IC₅₀ values ranging from 2.9 to 90.2 µM.

Network Pharmacology of Yougui Pill Combined with Buzhong Yiqi Decoction for the Treatment of Sexual Dysfunction

Purpose

We aimed to find the possible key targets of Yougui pill and Buzhong Yiqi decoction for the treatment of sexual dysfunction.

Materials and Methods

The composition of Yougui pill combined with Buzhong Yiqi decoction was obtained, and its effective components of medicine were screened using ADME; the component target proteins were predicted and screened based on the TCMSP and BATMAN databases. Target proteins were cross-validated using the CTD database. We performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses for target proteins using the Cytoscape plugin ClueGO + CluePedia and the R package clusterProfiler, respectively. Subsequently, protein-protein interaction (PPI) analyses were conducted using the STRING database. Finally, a pharmacological network was constructed.

Results

The pharmacological network contained 89 nodes and 176 relation pairs. Among these nodes, there were 12 for herbal medicines (orange peel, licorice, Eucommia, Aconite, Astragalus, Chinese wolfberry, yam, dodder seed, ginseng, Cornus officinalis, Rehmannia, and Angelica), 9 for chemical components (18-beta-glycyrrhetinic acid, carvacrol, glycyrrhetinic acid, higenamine, nobilin, quercetin, stigmasterol, synephrine, and thymol), 62 for target proteins (e.g., NR3C1, ESR1, PTGS2, CAT, TNF, INS, and TP53), and 6 for pathways (MAPK signaling pathway, proteoglycans in cancer, dopaminergic synapse, thyroid hormone signaling pathway, cAMP signaling pathway, and neuroactive ligand-receptor interaction).

Conclusion

NR3C1, ESR1, PTGS2, CAT, TNF, INS, and TP53 may be important targets for the key active elements in the decoction combining Yougui pill and Buzhong Yiqi. Furthermore, these target proteins are relevant to the treatment of sexual dysfunction, probably via pathways associated with cancer and signal transduction.

Active Natural Product Scaffolds against Trypanosomatid Parasites: A Review

Neglected tropical diseases caused by trypanosomatid parasites are a continuing and escalating problem, which devastate the less economically developed cultures in countries in which they are endemic by impairing both human and animal health. Current drugs for these diseases are regarded as out-of-date and expensive, with unacceptable side-effects and mounting parasite resistance, meaning there is an urgent need for new therapeutics. Natural products have long been a source of potent, structurally diverse bioactive molecules. Herein are reviewed natural products with reported trypanocidal activity, which have been clustered based on core structural similarities, to aid the future discovery of new trypanocidal core motifs with potential routes to synthetically accessible natural product cores suggested.

Acid-Induced Rearrangement of Epoxygermacranolides: Synthesis of Furanoheliangolides and Cadinanes from Nobilin

The acid-induced rearrangement of three epoxyderivatives of nobilin 1, the most abundant sesquiterpene lactone in Anthemisnobilis flowers, was investigated. From the 1,10-epoxyderivative 2, furanoheliangolide 5 was obtained, while the 4,5-epoxy group of 3 did not react. Conversely, when the 3-hydroxy function of nobilin was acetylated (12), the 4,5-epoxy derivative did cyclize into cadinanes (15 and 16) under Lewis acid catalysis. The reactivity of the 4,5- and 1,10-epoxy derivatives of nobilin (2 and 3) was compared with that of parthenolide, and rationalized on the basis of quantum chemical calculations. All isolated reaction products were fully characterized by spectroscopic and computational methods, and their in vitro anti-protozoal activity was evaluated. The paper could provide new insights into the biosynthesis of this class of natural products.

Antiprotozoal Activity-Based Profiling of a Dichloromethane Extract from Anthemis nobilis Flowers

A dichlomethane extract of Anthemis nobilis flower cones showed promising in vitro antiprotozoal activity against Trypanosoma brucei rhodesiense and Leishmania donovani, with IC₅₀ values of 1.43 ± 0.50 and 1.40 ± 0.07 μg/mL, respectively. A comprehensive profiling of the most active fractions afforded 19 sesquiterpene lactones, including 15 germacranolides, two seco-sesquiterpenes, one guaianolide sesquiterpene lactone, and one cadinane acid. Of these, 13 compounds were found to be new natural products. The compounds were characterized by extensive spectroscopic data analysis (1D and 2D NMR, HRMS, circular dichroism) and computational methods, and their in vitro antiprotozoal activity was evaluated. The furanoheliangolide derivative 15 showed high potency and selectivity in vitro against T. b. rhodesiense bloodstream forms (IC₅₀ 0.08 ± 0.01 μM; SI 63). In silico calculations were consistent with the drug-like properties of 15.

Natural Sesquiterpene Lactones as Potential Trypanocidal Therapeutic Agents: A Review

Chagas’ disease and Human African Trypanosomiasis are parasitic diseases that remain major health problems, mainly among the poorest and the most marginalized communities from Latin America and Africa. The scarcity of effective chemotherapy, due to the low investment in the research and development (R&D) of new drugs, together with a high incidence of side effects, and the emergence of drug resistance phenomena emphasize the urgent need for new prophylactic and therapeutic agents. Over the ages, humans have employed natural products to treat a wide spectrum of diseases. Recently, the pharmaceutical industry has focused on plant research and a large body of evidence has been collected to demonstrate the immense potential of medicinal plants as a source of bioactive compounds and lead molecules. In the field of parasitic diseases, drug development from plants has been successful for the sesquiterpene lactone (STL) artemisinin, which is employed as an antimalarial agent. STLs are a large group of naturally occurring terpenoids derived from plants that mostly belong to the Asteraceae family which exhibit a variety of skeletal arrangements and are the largest and most diverse category of natural products with an α-methylene-λ-lactone motif. STLs display a broad spectrum of biological activities such as antitumor, cytotoxic, antibacterial, anthelmintic, uterus contracting, antimalarial, neurotoxic, antiprotozoal and allergic (contact dermatitis) activities. In this context, the purpose of the present review is to provide an overview of the trypanocidal activity reported for STLs against Trypanosoma cruzi and T. brucei rhodesiense over the period 1993–2015.