[Chemical constituents from Clitocybe clavipes and their antitumor activities].

This paper aimed to study the chemical constituents from Clitocybe clavipes. Silica gel, ODS, Sephadex LH-20, and semi-p reparative HPLC were employed to separate the ethanol extract of C. clavipes. Six compounds were identified by ~1H-NMR, ~(13)CNMR,and ESI-MS as clavilactone L(1), clavilactone A(2), clavilactone B(3), clavilactone E(4), clavilactone H(5), and clav ilactone I(6). Among them, compound 1 was a new meroterpenoid with a 10-membered carbocycle connected to a hydroquinone. Theantitumor activities of compounds 1-6 were determined by the methyl thiazolyl tetrazolium(MTT) ass ay. The results showed that compounds 1-6 exerted inhibitory effects on the proliferation of human gastric cancer cells(MGC-803),human non-small cell lung cancer cells(A549), and cervical cancer cells(HeLa). Compound 1 exhibited significant inhibitory activity against MGC-803 cells, with the half maximal inhibitory concentration(IC_(50)) of 11. 76 µmol·L~(-1).

Cadinane-Type Sesquiterpenoids with Cytotoxic Activity from the Infected Stems of the Semi-mangrove Hibiscus tiliaceus.

Eight new cadinane sesquiterpenoids (1-8), along with two known compounds (9 and 10), were isolated from infected stems of the semi-mangrove plant, Hibiscus tiliaceus. The structures of compounds 1-8 were elucidated through the analysis of their 1D and 2D NMR and MS data, and their absolute configurations were determined by comparing their experimental and calculated ECD spectra and by single-crystal X-ray diffraction. The two confused known compounds (9 and 10) were resolved using single-crystal X-ray crystallography. Compounds 1-3 have novel norsesquiterpene carbon skeletons arising from a ring contraction rearrangement. All obtained isolates were evaluated against the HepG2 and Huh7 cell lines, and compounds 1b, 2b, 4, 6, and 8 showed cytotoxic activity toward both cell lines, with IC50 values ranging from 3.5 to 6.8 µM.

Cadinane-type sesquiterpenoid dimeric diastereomers hibisceusones A-C from infected stems of Hibiscus tiliaceus with cytotoxic activity against triple-negative breast cancer cells.

Three new cadinane-type sesquiterpenoid dimeric diastereomers (1-3) named hibisceusones A-C were obtained from the infected stems of Hibiscus tiliaceus. The structures were determined by NMR spectroscopy and MS techniques, and the absolute configurations were assigned by ECD and single-crystal X-ray diffraction techniques. Compounds 1-3 are diastereomers, and contain a 1,4-dioxane ring linearly fused to different cadinane-type polycyclic skeletons. This is the first time that such a structure has been identified in natural products. Compounds 1-3 exhibited cytotoxic activities, and 2 showed a significantly high anti-triple-negative breast cancer (TNBC) effect. The anti-cancer effect of compound 2 was 3-4 fold higher than that of 1 and 3. The anti-cancer effect was generated via the induction of the apoptosis of the MDA-MB-231 cells by inhibiting the PI3Kα pathway.

Natural Nitrogenous Sesquiterpenoids and Their Bioactivity: A Review.

Nitrogenous sesquiterpenoids fromnatural sourcesare rare, so unsurprisingly neither the potentially valuable bioactivity nor thebroad structural diversity of nitrogenous sesquiterpenoids has been reviewed before. This report covers the progressduring the decade from 2010 to February 2020 on the isolation, identification, and bioactivity of 391 nitrogen-containing natural sesquiterpenes from terrestrial plant, marine organisms, and microorganisms. This complete and in-depth reviewshouldbe helpful for discovering and developing new drugs of medicinal valuerelated to natural nitrogenous sesquiterpenoids.

Two new degradative cassane-type diterpenes isolated from Caesalpinia minax.

Cassane-type diterpenes are main bioactive constituents of Caesalpinia minax HANCE. As a part of our ongoing chemical investigation of C. minax, two new degradative cassane-type diterpenes, named caesalpins I (1) and J (2), were isolated from the EtOAc extract of the seeds of C. minax. The structures were elucidated by means of spectroscopic analysis.

Three new triterpenoid glycosides from Aronia melanocarpa (Michx.) Elliott.

Three new triterpenoid glycosides, 2α,3α,23,24-tetrahydroxyurs-12,19- dien-oic acid 28-O-ß- D -glucopyranoside (1), 2α,3ß,23,24-tetrahydroxyurs-12, 19(29) -dien-28-oic acid 28-O-ß- D -glucopyranoside (2), and 2α,3ß,23,24-tetrahydroxyurs-12, 18-dien-28-oic acid 28-O-ß- D -glucopyranoside (3) were isolated from Aronia melanocarpa (Michx.) Elliott. Their structures were elucidated by extensive spectroscopic methods. All the isolated compounds displayed moderate inhibitory activity against nitric oxide production in macrophages.

Three new compounds with their anti-glioma effects from the roots of Arnebia guttata Bunge.

Three new compounds, arneatas A-C (1-3), together with three known compounds (4-6) were isolated from the roots of Arnebia guttata Bunge. The structures were established on the basis of extensive spectroscopic data including NMR and HRESIMS. All the new compounds (1-3) were tested for their cytotoxic activity against two glioma cell lines (U118-MG and U373-MG) in vitro after treatment for 48 h. Compound 1 exhibited moderate cytotoxic activity against U118-MG and U373-MG glioma cell lines, with IC50 values of 10.4 and 17.5 µM, respectively.

Two new diterpenes, neocaesalpin MR and minaxin C, from Caesalpinia minax.

Two new cassane-type diterpenes, neocaesalpin MR and minaxin C, were isolated from Caesalpinia minax HANCE. The structures of these compounds were elucidated by means of spectroscopic analysis. Among these isolated compounds, neocaesalpin MR showed mild activities toward HeLa and colon cancer (HCT-8) human cancer cell lines.

Abietane-Type Diterpenoids From Nepeta bracteata Benth. and Their Anti-Inflammatory Activity.

Terpenes possess a wide range of structural features and pharmaceutical activities and are promising for drug candidates. With the aim to find bioactive terpene molecules, eight new compounds were isolated from the medicinal plant Nepeta bracteata Benth., including seven new abietane-type diterpenoids (1-7), along with a new ursane-type triterpenoid (8). The structures of compounds 1-8 were elucidated through the detailed spectroscopic analyses of their 1D and 2D NMR and MS data, and the absolute configurations of compounds 1-7 were determined by comparing their experimental and calculated ECD spectra. Compound 1 was a novel degraded carbon diterpene with the disappearing of methyl signal at C-19, while compound 7 possessed a new norabietane-type diterpenoid carbon skeleton with the presence of five-membered lactone arising from ring rearrangement. The anti-inflammatory of all obtained isolates were evaluated on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the results of anti-inflammatory activity screening showed that compared with the LPS model group, all compounds were significantly down-regulation the TNF-α inflammatory factor at the specific concentration, except for compound 6.