Unprecedented sesterterpenoids, orientanoids A-C: discovery, bioinspired total synthesis and antitumor immunity

Jatrophane and ingenane diterpenoids with anti-inflammatory activity from Euphorbia esula

A phytochemical investigation into the plants of Euphorbia esula L. has yielded 19 diterpenoids, comprising 17 jatrophane-type (1-7 and 9-18) and two ingenane-type (8 and 19). The structures of these compounds were elucidated by a combination of spectrum elucidations, quantum chemical calculations, and X-ray single crystal diffraction. Biological evaluations demonstrated that compounds 6, 8, 18, and 19 show significant anti-inflammatory activity with IC50 values within 10 μM, without displaying any morphological signs of cytotoxicity. Further biological analysis revealed that euphoresulin A (8) is involved in the suppression of inflammatory response by blocking the activation of NF-κB/MAPK and activating Nrf2/HO-1 singling pathways.

Practically complementary size exclusion chromatography and reversed-phase liquid chromatography for the preparative separation of structurally similar flavone-C-glycosides

In this study, a practicably complementary size exclusion chromatography and reversed-phase liquid chromatography method was constructed and applied to efficiently separate and purify structural analogs or isomers from natural products. First, a ternary styrene-divinylbenzene matrix CHP20P medium-pressure elution system was applied for Ligustrum qianluoenenst leaf crude sample pretreatment, with a recovery of 91.2 %, and 13.0 g of the target fraction Fr4 was obtained. A complementary HW-40C SEC and ReproSil-Pur C18 AQ RPLC system was subsequently constructed by optimizing the HW-40C separation conditions and ReproSil-Pur C18 AQ analysis. Finally, the established complementary SEC and RPLC method was used for the separation and purification of compounds from Ligustrum qianluoenenst leaf target fraction Fr4, and 12 flavone-C-glycosides were successfully prepared with purities exceeding 95 %. The overall methodologies established for flavone-C-glycoside preparative isolation have the potential to maximize the possibility of discovering more structural analogs, including new structural analogs or isomers from natural products.

Survey of natural products reported by Asian research groups in 2023

The new natural products reported in 2023 in peer-reviewed articles in journals with good reputations were reviewed and analyzed. The advances made by Asian research groups in the field of natural products chemistry in 2023 were summarized. Compounds with unique structural features and/or promising bioactivities originating from Asian natural sources were discussed based on their structural classification.

Immunosuppressive Breviane Spiroditerpenoids from Penicillium bialowiezense Isolated from a Medicinal Plant

Breviane spiroditerpenoids are a small group of structurally interesting and complex meroterpenoids. This work focused on an endophytic fungus Penicillium bialowiezense ZBWPQ-27 that was isolated from a medicinal plant Euphorbia neriifolia, leading to the isolation of 15 breviane spiroditerpenoids with four types of polycyclic systems (1-6 and 9-17), and two new carotane sesquiterpenoids (7 and 8). The structures including absolute configurations of the new compounds 1-8 were elucidated by spectroscopic data analysis and electronic circular dichroism (ECD) calculations. In addition, the misassigned NMR data of several resonances of the 5-methyl-TAL motif (E ring) in those of known brevianes (9-15) were corrected by spectroscopic data analysis. Biological tests revealed that brevianes with the type A ring system (6/6/6/5/6) showed moderate to significant immunosuppressive activities, and compound 11 displayed the most potent inhibitory activities against concanavalin A (ConA)-induced T cell proliferation (IC50 4.1 ± 0.2 μM) and lipopolysaccharide (LPS)-induced B cell proliferation (IC50 4.6 ± 0.2 μM), with good SI values of 28 ± 2 and 25 ± 4, respectively.

Terpenoids of plants from Chloranthaceae family: chemistry, bioactivity, and synthesis

Covering: 1976 to December 2023Chloranthaceae is comprised of four extant genera (Chloranthus, Sarcandra, Hedyosmum, and Ascarina), totaling about 80 species, many of which have been widely used as herbal medicines for diverse medical purposes. Chloranthaceae plants represent a rich source of structurally interesting and diverse secondary metabolites, with sesquiterpenoids and diterpenoids being the predominant structural types. Lindenane sesquiterpenoids and their oligomers, chemotaxonomical markers of the family Chloranthaceae, have shown a wide spectrum of bioactivities, attracting significant attention from organic chemists and pharmacologists. Recent achievements also demonstrated the research value of two unique structural types in this plant family, sesquiterpenoid-monoterpenoid heterodimers and meroterpenoids. This review systematically summarizes 682 structurally characterized terpenoids from 22 Chloranthaceae plants and their key biological activities as well as the chemical synthesis of selected terpenoids.

Hot off the press

A personal selection of 32 recent papers is presented covering various aspects of current developments in bioorganic chemistry and novel natural products such as dcalycinumine A from Daphniphyllum calycinum.