Sarglamides A-E, Indolidinoid-Monoterpenoid Hybrids with Anti-neuroinflammatory Activity from a Sarcandra Species

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.

Eleutherlenes A-D, Diverse Types of Naphthalene Derivatives with Anti-inflammatory Activity from Eleutherine bulbosa

Eleutherlene A (1), an unprecedented carbon skeleton featuring an aryl-fused 6-methyl-2,7-dioxabicyclo[3.2.1]octane unit, and eleutherlene B (2), a naphthoquinone derivative with interesting ring fusion of an α,β-unsaturated γ-lactam and a tetrahydropyran moiety, along with two novel naphthoquinone alkaloids, eleutherlenes C (3) and D (4), were isolated from Eleutherine bulbosa and identified. Their structures were elucidated by spectroscopic analyses along with computer-assisted structure elucidation, including ACD/Structure Elucidator and computational calculations and X-ray crystal diffraction. A plausible biosynthetic route for 1 and 2 was proposed. Compound 1 showed significant anti-inflammatory activity with respect to the inhibition of pro-inflammatory mediators NO, IL-1β, iNOS, and COX-2. Mechanistically, compound 1 inhibited the inflammatory response by suppressing NF-κB/MAPK and activating the Nrf2/Keap1 signaling pathway in LPS-induced RAW 264.7 cells.

Asymmetric Total Syntheses of Sarglamides A, C, and E

The asymmetric total syntheses of sarglamides A, C, and E in concise and protecting group free fashion is disclosed. Key steps involve an endo-selective Diels-Alder reaction to construct the bicyclo[2.2.2]nonane framework, a nucleophilic addition and an intramolecular aza-Michael addition to install the pyrrolidine ring, and a final cinnamoylation reaction. Sarglamide C is biomimetically transformed into E through a Brønsted acid mediated oxy-cyclization. Sarglamide D is also accessible from C based on Yue's research. This work provides an efficient asymmetric approach to the syntheses of sarglamides and also provides insights into understand the plausible biogenetic pathway of these monoterpenoid-indolidinoid hybrid structures.

The Chemistry and Pharmacological Properties of the Constituents of Toussaintia Orientalis - An Endangered Treasure of Biomedical Agents

Toussaintia orientalis Verdc. (Annonaceae) is a medicinal plant species endemic to Tanzania. It is classified under the International Union for Conservation of Nature (IUCN) as an extremely endangered species threatened with extinction. The review covers the phytochemistry of this plant species and the pharmacological properties of the compounds obtained therefrom. The chemistry of this plant species entails natural products with different structures including uncommon cinnamoyl tetraketide derivatives, aristolactam alkaloids, and flavonoids. The review identifies 27 compounds belonging to different subclasses of natural products obtained from this species for the past fourteen years (2010-2024). These compounds are discussed along with other 13 related natural products. T. orientalis derived compounds exhibit varied potential pharmacological applications as antibacterial, anticancer, anti-inflammatory, antiviral, and neuroprotective agents. Some of the reported compounds displayed pharmacological properties corroborating the use of this plant species in traditional medicine. This review provides baseline data as one comprehensive compilation that will ignite interest and guide future research and development of therapeutic agents inspired by the chemodiversity presented by this plant species while at the same time attracting the attention of plant conservationists to initiate efforts to conserve this highly endangered biomedical treasure.

A review of botany, ethnomedicine, phytochemistry, pharmacology and toxicology of Sarcandra species

BACKGROUND

Sarcandra is one of the five genera of Chloranthaceae, which has a long history of medicinal use and high medicinal value, with excellent therapeutic effects on liver cancer, pneumonia, colitis, bone fractures, and dysentery. Among its species, Sarcandra glabra (Thunb.) Nakai has been extensively utilized in diverse compound formulations, toothpaste, tea, daily commodities, as well as health supplements. Therefore, in terms of its medicinal properties and effectiveness, the genus has considerable potential for development and utilization.

PURPOSE

This paper presents a systematic review of the botany, ethnomedicine, phytochemistry, pharmacology, and toxicology of Sarcandra plants, aiming to deepen our understanding of Sarcandra properties further, to provide a reference for the rational utilization of Sarcandra plant resources, and at the same time laying a foundation for the development of new medicines and the study of natural products.

METHODS

In this paper, we collected information about Sarcandra species through PubMed, Science Direct, Web of Science, Baidu Scholar, Google Scholar, CNKI, and other databases using the keywords Sarcandra, botany, traditional uses, chemical compounds, pharmacology and toxicology. Its botanical-related information was obtained through the Flora of China (www.iplant.cn).

RESULTS

Three species of Sarcandra plants worldwide are distributed from eastern Asia to India. This genus has a long history of medicinal uses, high medicinal value, and a wide range of applications. At present, 462 compounds have been isolated and identified from Sarcandra plants, and their diversity contributes to the diversity of the pharmacological effects of Sarcandra plants. Numerous studies have shown that Sarcandra plants exhibit significant antitumor, antibacterial, anti-inflammatory, antimalarial, antiviral, antithrombocytopenia, immunomodulatory, antioxidant, hepatoprotective, hypoglycemic and hypolipidemic effects, with low toxicity and side effects. However, most studies have focused on Sarcandra glabra (Thunb.) Nakai and studies on other plants of the genus have yet to be explored.

CONCLUSIONS

Sarcandra plants have a wide range of clinical uses and diverse chemical compounds. However, the main research has been concentrated on Sarcandra glabra (Thunb.) Nakai, and future research should explore the medicinal properties of other Sarcandra plants to expand their potential clinical applications. Meanwhile, the pharmacological activities of compounds from Sarcandra species need to be studied in greater depth and detail to provide an appropriate scientific basis for developing new drugs and natural product research.

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.

Cytotoxic diterpenoids from Croton kongensis inhibiting tumor proliferation and migration

Thirty-two diterpenoids including 18 ent-kauranes (1-6, and 12-23), nine 8,9-seco-ent-kauranes (7-8, and 24-30), four ent-abietanes (9-10, and 31-32), and one crotofolane (11) were isolated from the twigs and leaves of Croton kongensis. The structures of previously unreported crokokaugenoids A-H (1-8), crokoabiegenoids A-B (9-10), and crokocrotogenoid A (11) were determined by spectroscopic data analyses, TDDFT-ECD and GIAO NMR calculations, and X-ray crystallographic studies. All compounds were evaluated for their cytotoxic activity against five human tumor cell lines, and the structure-activity relationships were discussed. Biological tests exhibited that compound 1 possessed strong anti-proliferation activity, arrested cell cycle at G2/M phase, and induced cell apoptosis of MDA-MB-231. The mechanism investigation showed that compound 1 can inhibit tumor proliferation and migration by targeting mitochondria to increase intracellular reactive oxygen species (ROS) and regulating STAT3 and FAK signal pathways. Collectively, these findings supported the great potential of compound 1 as a hopeful anticancer agent.

Intriguing steroid glycosides for cancer therapy by suppressing the DNA damage response and mTOR/S6K signaling pathways

Two rare 8-hydroxysteroid glycosides (6-7), and their downstream metabolites (1-5) with an unprecedented 6/6/5/5/5-pentacyclic scaffold, together with seven known analogues (8-14) were isolated from the twigs and leaves of Strophanthus divaricatus. Their structures were fully assigned by analysis of the spectroscopic and ECD data, NMR calculations, X-ray crystallographic study, and chemical methods. In addition, the inhibitory effects of 1-14 on liver and lung cancer cell lines were evaluated, and preliminary structure-activity relationship was discussed. Data-independent acquisition (DIA)-based quantitative proteomic analysis and biological verification of H1299 cells suggested that this family of compounds may play an anticancer role by suppressing both DNA damage response (DDR) and mTOR/S6K signaling pathways.

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.

Asymmetric total syntheses of sarglamides A, C, D, E, and F

Sarglamides A-E were identified as a structurally new class of alkaloids with potential application for inflammation-associated diseases. Reported is the first asymmetric total synthesis of sarglamides A, C, D, E, and F within 7 steps, featuring an intermolecular Diels-Alder cycloaddition of (S)-phellandrene and 1,4-benzoquinone and intramolecular (aza-)Michael addition to construct the tetracyclic core of sarglamides. Importantly, our work demonstrated that the hypothetic Diels-Alder reaction of α-phellandrene with dienophile toussaintine C (or analogues) originally proposed as a biosynthetic pathway was not viable under non-enzymatic conditions. Additionally, we discovered novel and efficient double cyclization (cycloetherification and oxa-Michael cyclization) to construct the core framework of sarglamides E and D. Our concise synthetic strategy might allow rapid access to a library of sarglamide analogues for further evaluation of their bioactivity and mode of action.

Construction of Hydroindole Skeleton by Photocatalytic Oxidative Dearomatization and Cyclization Sequence, and a Concise Synthesis of Melodamide A and (±)-Toussaintine C

A method of synthesizing hydroindole skeletons has been developed by using photocatalytic oxidative dearomatization and an aza-Michael addition sequence. Using this method, optically active hydroindoles, which are often used in natural product synthesis as chiral building blocks, can be easily prepared with >99% ee. Furthermore, the synthesis of melodamide A and (±)-toussaintine C was achieved using this method as a key step.

Sarcanoids A and B, two new lindenane-type sesquiterpenoid dimers from the aerial parts of Sarcandra glabra

Sarcanoids A and B (1 and 2), two new lindenane-type sesquiterpenoid dimers with a γ-hydroxysenecioate moiety at C-15', were isolated from the ethyl acetate extract of Sarcandra glabra. The structures were elucidated by extensive analysis of spectroscopic data, and their absolute configurations were determined by single-crystal X-ray crystallography. Compounds 1 and 2 showed moderate inhibitory activities on the nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 macrophages.

Asymmetric Total Synthesis of (+)-Chuanxiongnolide L1 via a Stereoselective Oxidative Dearomatization/Diels-Alder Strategy

The first asymmetric total synthesis of chuanxiongnolide L1 was achieved in 16 steps and 1.9% overall yield by employing a bioinspired chiral auxiliary strategy. The key steps involving asymmetric oxidative dearomatization of chiral amino ether and subsequent asymmetric Diels-Alder reaction of the resulting masked chiral ortho-benzoquinone were adopted.

Anti-Inflammatory Salicin Derivatives from the Barks of Salix tetrasperma

The genus Salix L. is traditionally used in folk medicine to alleviate pain caused by various kinds of inflammation. In the present study, 10 undescribed salicin derivatives along with 5 known congeners were isolated from the barks of Salix tetrasperma, and their structures were elucidated by spectroscopic analyses, single-crystal X-ray diffraction, electronic circular dichroism (ECD) calculations, and chemical conversions. Compounds 4-6 significantly inhibited NO production in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages, and the most active 4 obviously suppressed the production of IL-1β and IL-6 and decreased iNOS and COX-2 expression in a dose-dependent manner. Further Western blotting analysis revealed that the anti-inflammatory mechanism of 4 is possibly mediated through the MAPK and NF-κB signaling pathways.

Monoterpenoid indole alkaloids from Alstonia scholaris and their Toxoplasma gondii inhibitory activity

Nine previously unreported various types of monoterpenoid indole alkaloids, together with seven known analogues were isolated from the stem barks of Alstonia scholaris through a silica gel free methodology. The structures of 1-9 were elucidated by spectroscopic data analysis, electronic circular dichroism calculations, and single-crystal X-ray diffraction. Compound 1 is a modified echitamine-type alkaloid with a novel 6/5/5/7/6/6 hetero hexacyclic bridged ring system, and 8 and 9 exist as a zwitterion and trifluoroacetate salt, respectively. The anti-Toxoplasma activity of all isolates on infected Vero cells were evaluated, which revealed that compound 14 at 0.24 μM displayed potent activity. This study expanded the structural diversity of alkaloids of A. scholaris, and presented their potential application in anti-Toxoplasma drug development.

Sesquiterpenoids and Cytochalasins with Immunosuppressive Activity from Sonchus wightianus

The plant species, Sonchus wightianus DC., was historically used in China for both medicinal and dietary uses. In present study, seven new guaiane sesquiterpenoids (1-7) and one cytochalasin (8), along with five known guaianes (9-13) and two known cytochalasins (14 and 15), were isolated from the whole plants of S. wightianus. These guaianes showed structural variations in the substituents at C-8 and/or C-15, and compounds 6 and 7 are two sesquiterpenoid glycoside derivatives. Their structures were determined by extensive analysis of spectroscopic, electronic circular dichroism, and X-ray diffraction data, and chemical method. Biological tests revealed that compounds 5 and 8 are potent and selective immunosuppressive reagents.

Maydistacins A-G, Terpestacin-type Sesterterpenoids with Anti-inflammatory Activity from the Phytopathogenic Fungus Bipolaris maydis

Seven undescribed terpestacin-type sesterterpenoids, maydistacins A-G (1-7), along with two known congeners (8 and 9), were isolated from the phytopathogenic fungus Bipolaris maydis collected from the leaves of Hypericum longistylum. The structures of 1-7 were elucidated based on extensive spectroscopic analysis, chemical methods, NMR calculations with DP4+ probability analysis, and comparison of experimental and calculated electronic circular dichroism (ECD) calculations. In vitro anti-inflammatory effects of these compounds were tested in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Compound 1 exhibited inhibition of the production of nitric oxide in LPS-induced macrophages, with an IC50 value of 19 ± 2 μM. A dexamethasone control displayed an IC50 value of 6.7 ± 0.6 μM. Compound 1 is the first terpestacin-type sesterterpenoid reported to display anti-inflammatory activity and may provide a novel chemical scaffold for the discovery of new anti-inflammatory drugs.

A comprehensive review on the chemical constituents, sesquiterpenoid biosynthesis and biological activities of Sarcandra glabra

Sarcandra glabra (Thunb.) Nakai is a perennial evergreen herb categorised within the Sarcandra Gardner genus under the Chloranthaceae family. Indigenous to tropical and subtropical regions of East Asia and India, this species is extensively distributed across China, particularly in the southern regions (Sichuan, Yunnan, and Jiangxi). In addition to its high ornamental value, S. glabra has a rich history of use in traditional Chinese medicine, evident through its empirical prescriptions for various ailments like pneumonia, dysentery, fractures, bruises, numbness, amenorrhea, rheumatism, and other diseases. Besides, modern pharmacological studies have revealed various biological activities, such as antitumour, anti-bacterial, anti-viral anti-inflammatory and immunomodulatory effects. The diverse chemical constituents of S. glabra have fascinated natural product researchers since the 1900s. To date, over 400 compounds including terpenoids, coumarins, lignans, flavonoids, sterols, anthraquinones, organic acids, and organic esters have been isolated and characterised, some featuring unprecedented structures. This review comprehensively examines the current understanding of S. glabra's phytochemistry and pharmacology, with emphasis on the chemistry and biosynthesis of its unique chemotaxonomic marker, the lindenane-type sesquiterpenoids.