Echingridimer A, an Oxaspiro Dimeric Sesquiterpenoid with a 6/6/5/6/6 Fused Ring System from Echinops grijsii and Aphicidal Activity Evaluation

Four new diarylheptanoids and two new terpenoids from the fruits of Alpinia oxyphylla and their anti-inflammatory activities

Four previously unreported diarylheptanoids (1a/1b-2a/2b), one undescribed sesquiterpenoid (8), one new diterpenoid (12), and twelve known analogs were isolated from the fruits of Alpinia oxyphylla. The structural elucidation of these compounds was achieved through a comprehensive analysis of spectroscopic data, single-crystal X-ray diffraction, electronic circular dichroism (ECD), and modified Mosher's method. Enantiomeric mixtures (1a/1b, 2a/2b, 3a/3b, 4a/4b, and 5a/5b) were separated on a chiral column using acetonitrile-water mixtures as eluents. Among them, compounds 3a/3b and 4a/4b were isolated as optically pure enantiomers in the initial chiral separation. Furthermore, most of the isolates were evaluated for their inhibitory effects against the production of nitric oxide (NO) and interleukin-6 (IL-6) in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Interestingly, 2 and 4 showed significant inhibitory activities against NO production with IC50 values of 33.65 and 9.88 μmol·L-1 (hydrocortisone: IC50 34.26 μmol·L-1), respectively. Additionally, they also partially reduced the secretion of IL-6.

Eudesmane-type sesquiterpenoids: Structural diversity and biological activity

Sesquiterpenoids are integral constituents of terpenoid-bearing plants, comprising a diverse and abundant class of natural compounds, among which eudesmane-type sesquiterpenoids have bicyclic structures that feature the fusion of two six-membered carbon rings, thereby attracting considerable attention. They are widespread in nature, with multifaceted biological activities such as anti-inflammatory, anticancer, antimicrobial, antimalarial, and insecticidal activities, thus gaining focus in life science research. The discovery and identification of these active compounds have laid a foundation for unraveling their potential medicinal value. In this review, we comprehensively explore the natural eudesmane-type sesquiterpenoids isolated (totaling 391 compounds) between 2016 and 2022, elucidating their chemical structures, plant distribution patterns, and pertinent biological properties. Accordingly, the study serves not only as a framework for researchers to thoroughly comprehend these compounds but also as a robust reference for future endeavors aimed at exploring the pharmaceutical potential and prospective applications of these molecules.

A Review of the Phytochemistry and Biological Activities of Echinopsis Radix

The main varieties of Echinopsis Radix recorded in the Chinese Pharmacopoeia are the roots of Echinops latifolius Tausch or Echinops grijsii Hance. However, the chemical constituents and biological activities of this herb have not been reviewed. In order to clarify the chemical constituents of the main varieties of this herb and improve the quality of Chinese medicinal material resources, this paper systematically reviewed their chemical constituents and related biological activities. Phytochemical investigations reveal eighty-five compounds including fort y-nine thiophenes (1-49), eight flavonoids (50-57), seven caffeic acids and its derivatives (58-64), eight sesquiterpenoids (65-72), and thirteen triterpenoids and other compounds (73-85) were reported from Echinopsis Radix. The review of biological activities suggests that thiophenes are the main secondary metabolites of the medicinal material which exert antitumor, insecticidal and antifungal activities. In addition, caffeic acid and its derivatives and sesquiterpenes are potential active ingredients worthy of further study. This review provides an important scientific basis for the development of active ingredients and resource quality evaluation of Echinopsis Radix.

Chlorahupetenes A-D, Four Eudesmane-Type Sesquiterpenoid Dimer Enantiomers with Two Unusual Carbon Skeletons from Chloranthus henryi Var. hupehensis

(+)- and (-)-Chlorahupetenes A (1a and 1b), B (2a and 2b), C (3a and 3b), and D (4a and 4b), four unique enantiomeric pairs of eudesmane-type sesquiterpenoid dimers with two new carbon skeletons, were isolated from the aerial parts of Chloranthus henryi var. hupehensis. Compounds 1 and 2 possess an unprecedented 6/6/5/6/6 pentacyclic carbon skeleton with a new dimerization pattern of two eudesmane-type sesquiterpenoids. Compounds 3 and 4, which are fused with two eudesmane-type sesquiterpenoids via an unprecedented five-membered O-heterocyclic ring, represent a new 6/6/5/5/6/6/5 heptacyclic ring system. The structures of the compounds were determined through spectroscopic data and X-ray crystallography. Compounds 1a-3b significantly inhibited NO production with IC₅₀ values ranging from 9.62 to 12.91 μM. Moreover, compounds 1b and 3a suppressed the production of a proinflammatory mediator (TNF-α) and enzyme expression (iNOS) at the mRNA level.

Nine sesquiterpenoid dimers with four unprecedented types of carbon skeleton from Chloranthus henryi var. hupehensis

Chlorahupetones A–I (1–9), nine sesquiterpenoid dimers, were isolated from Chloranthus henryi var. hupehensis.

Survey of natural products reported by Asian research groups in 2019

The new natural products reported in 2019 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 2019 were summarized. Compounds with unique structural features and/or promising bioactivities originating from Asian natural sources were discussed based on their structural classification.

Natural disesquiterpenoids: an update

This review highlights the progress on the isolation, bioactivity, biogenesis and total synthesis of dimeric sesquiterpenoids since 2010.