Five New Terpenes with Cytotoxic Activity from Pestalotiopsis sp.

Five new compounds called Pestalotis A–E (1–5), comprising three monoterpene-lactone compounds (1–3), one tetrahydrobenzofuran derivative (4), and one sesquiterpene (5), were isolated from the EtOAc extract of Pestalotiopsis sp. The structures of the new compounds were elucidated by analysis of their NMR, HRMS, and ECD spectra, and the absolute configurations were established through the comparison of experimental and calculated ECD spectra. All compounds were tested for antitumor activity against SW-480, LoVo, HuH-7, and MCF-7. The results showed that compounds 2 and 4 exhibited potent antitumor activity against SW-480, LoVo, and HuH-7 cell lines. Furthermore, compound 4 was assessed against HuH-7, and the results indicated that the rate of apoptosis was dose-dependent.     

Bioassay Guided Isolation and Identification of a Cytotoxic Compound from Azadirachta indica Leaves

This study aimed to investigate the structural features of the isolated flavonol glycoside, which might behave as a cytotoxic compound. The hexane, chloroform, ethyl acetate, and aqueous fractions of an 80% methanol solution of Neem (Azadirachta indica) (Family: Meliaceae) leaves were subjected to a cytotoxicity bioassay against brine shrimp, Artemia salina. The ethyl acetate fraction exhibited the highest cytotoxic effect, supported by the lowest lethal concentration, a LC₅₀ value of 1.35±0.40 ppm. A compound, Quercetin 3‐O‐β‐D‐glucopyranoside, was isolated from the most toxic fraction of the ethyl acetate via preparative liquid chromatography and then identified via ultraviolet‐visible (UV‐Vis), infrared (IR), mass spectrum (MS) and nuclear magnetic resonance (NMR) analyses. The compound was further confirmed by physical state, color, solubility, and melting point determination. The cytotoxic results suggest that the leaf ethyl acetate fraction consists of toxic compounds, which point towards the isolation of Quercetin 3‐O‐β‐D‐glucopyranoside.     

Iridoids from Viburnum cylindricum

Two new iridoids, methyl (+)‐rel‐(1R,3S,4R,5R,8R,9R)‐1,3,4,5,8,9‐hexahydro‐8‐hydroxy‐3‐methoxy‐2H‐1a,2‐dioxacyclopent[cd]indene‐4‐carboxylate ( 1 ) and methyl (+)‐rel‐(1R,3S,4S,5R,8R,9R)‐1,3,4,5,8,9‐hexahydro‐8‐hydroxy‐3‐methoxy‐2H‐1a,2‐dioxacyclopent[cd]indene‐4‐carboxylate ( 2 ), were isolated from Viburnum cylindricum along with 14 known compounds. Their structures were determined by spectroscopic analyses. This type of iridoids bearing a MeO group at C(3) was discovered for the first time.     

Iridoids from Gardenia jasminoides

The dichloromethane extract of the air-dried flowers of Gardenia jasminoides Ellis. afforded a new iridoid natural product (1), and a diastereomeric mixture of two new iridoids (2a and 2b) in a 2 : 1 ratio. Their structures were elucidated by extensive 1D and 2D NMR spectroscopy. Antimicrobial tests on 1 indicated that it was moderately active against Candida albicans; slightly active against E. coli, Pseudomonas aeruginosa, Staphylococcus. aureus, and Trichophyton mentagrophytes; and inactive against Bacillus subtilis and Aspergillus niger.     

Terpenes from Schisandra sphenanthera

One novel, highly oxygenated nortriterpenoid, schintrilactone C ( 1 ), and four known compounds, 2 – 5 , were isolated from the rattan of Schisandra sphenanthera. Their structures were determined by analysis of 1D‐ and 2D‐NMR spectroscopic data. Schintrilactone C is the third example of wuweiziartane‐type nortriterpenoids, bearing a modified five‐membered D ring, a δ‐lactone E ring, and a spirocyclic moiety in the side chain at C(13).     

Cytotoxic Terpenes from the Stems of <i>Dipterocarpus obtusifolius</i> Collected in Cambodia

From the stems of Dipterocarpus obtusifolius, five new triterpenes, 3-oxo-20-hydroxy-30α-methyl,17(29)α-epoxy-28-norlupane (1), 3-oxo-20-hydroxy-30β-methyl-17(29)α-epoxy-28-norlupane (2), 3,20-dioxo-28,29-norlupan-17α-ol (3), 27-demethyl-20(S)-dammar-23-ene-20-ol-3,25-dione (4), and 3-epi-cecropic acid (5) together with 13 known compounds including diterpene, sesquiterpenes and triterpenes were isolated and characterized. All isolates were tested for their cytotoxicities against a small panel of human cancer cell lines. Of the tested compounds, compounds 4-11 were found to be cytotoxic against one or more human cancer cell lines.     

Flavonol Glycosides and Iridoids from Asperula lilaciflora

A new flavonol glycoside, quercetin 3‐O‐[6′′′‐O‐3,5‐dihydroxycinnamoyl‐β‐glucopyranosyl‐(1→2)]‐β‐galactopyranoside (named lilacifloroside; 1 ) and a new iridoid 2 (named asperulogenin), were isolated from the aerial parts of Asperula lilaciflora in addition to eight known secondary metabolites, i.e., quercetin, kaempferol, quercetin 3‐O‐β‐glucopyranosyl‐(1→2)‐β‐galactopyranoside, quercetin 3‐O‐β‐glucopyranosyl‐(1→2)‐arabinopyranoside, asperuloside, deacetylasperulosidic acid, asperulosidic acid methyl ester, and chlorogenic acid. The structures were elucidated on the basis of extensive 1D‐ and 2D‐NMR experiments as well as MS data. Compound 1 contains the rare 3,5‐dihydroxycinnamoyl moiety in its structure. This work constitutes the first phytochemical study of the title plant.     

Biologically Active Iridoids from Hedyotis diffusa

Two new iridoids, 10‐O‐benzoyl‐6′‐O‐α‐L ‐arabino(1→6)‐β‐D ‐glucopyranosylgeniposidic acid ( 1 ), deacetyl‐6‐ethoxyasperulosidic acid methyl ester ( 2 ), along with 14 other known iridoids, were isolated from the whole plant of Hedyotis diffusa Willd. Their structures were determined on the basis of spectroscopic analysis. The short‐term‐memory‐enhancement activities of compounds 1, 7 – 9, 11 , and 13 were evaluated on an Aβ transgenic drosophila model.     

Iridoids from seeds of Gentiana lutea

In the seeds of Gentiana lutea L. there were also detected, in addition to the known sweroside and getiopicroside, loganic acid 3 and trifloroside 4 that is present as main glycosidic component. The structures of 3 and 4 were established by spectroscopic studies.     

Iridoids from Phlomis ostrowskiana Regel plant

Russian Chemical Bulletin - The structures of glycosylated iridoids extracted from Phlomis ostrowskiana R. plant species of Lamiaceae family were determined by mass spectrometry and NMR spectroscopy.     

Iridoids from the Bark of Alstonia scholaris

Four new 11‐noriridoids named scholareins A–D ( 1 – 4 ), along with three known derivatives, isoboonein ( 5 ), alyxialactone ( 6 ), and loganin ( 7 ), were isolated from EtOH extracts of the bark of Alstonia scholaris by chromatographic methods. Their structures were identified by extensive mass‐spectrometric and spectroscopic (especially 2D‐NMR) experiments.     

Iridoids from the Roots of Valeriana jatamansi

Three new iridoids, jatamanins N–P ( 1 – 3 ), along with the seven known iridiods 4 – 10 , were isolated from the roots of Valeriana jatamansi. Compound 1 is an unusual iridoid bearing two epoxy bridges between C(3) and C(6) and between C(1) and C(10), forming a unique cage‐like rigid skeleton. The structures of the new compounds were assigned on the basis of spectroscopic methods.     

Two New Antibacterial Iridoids from Patrinia rupestris

Patrinia rupestris has long been used as Chinese folk medicine for treatment of enteritis, appendicitis and hepatitis1. The chemical studies of this plant have not been reported till now, and iridoid containing chlorine has not been isolated from Patrinia…     

海绵中提取的异臭椿萜类化合物作用靶标的识别

采取了包括化学结构相似性学习、靶标聚类分析以及反向对接筛选等多种方法在内的综合性策略, 尝试对中国南海海绵中提取得到的异臭椿萜类化合物进行生物学活性和作用靶标的预测. 结果表明: 这类化合物具有治疗心肌缺血和抗肿瘤的潜在生物学活性; 表皮细胞生长因子受体(EGFR), 焦点(局部)粘着斑激酶(FAK), 胰岛素样生长因子1受体 (IGF1-R), c-Src激酶以及血管表皮生长因子受体2 (VEGF-R2)是这类化合物可能的作用靶标. IC₅₀值从0.41 g·m^-3 (0.41 μg·mL^-1)到9.8 g·m^-3 (9.8 μg·mL^-1)不等. 活性数据显示这些海绵提取的海洋天然产物可作为先导化合物, 通过进一步的优化获得新的药物. 同时还讨论了化合物与预测靶标的结合模式, 结果显示四个化合物都与相应的受体有较好的结合.     

Iridoids from Neopicrorhiza scrophulariiflora and their hepatoprotective activities in vitro

Four new non-glycosidic iridoids, piscrocins D (1), E (2), F (6), and G (7), as well as two new iridoid glycosides, piscrosides A (8) and B (9), were isolated from the roots of Neopicrorhiza scrophulariiflora (Scrophulariaceae), together with seven known iridoids. The structures of the isolated compounds were established by means of 1D and 2D NMR spectroscopy and chemical methods. The hepatoprotective activities of these compounds were evaluated by measuring their effects on CCl(4)-induced hepatocytes damage in vitro, and the structure-activity relationships were also discussed.     

Iridoids ofVerbascum georgicum

From the epigeal part ofVerbascum georgicum Benth., in addition to aucubin, as the main component of the total iridoids a new iridoid has been isolated — 6-α-L-(4′-p-methoxy-trans-cinnamoyl)rhamnopyranosylcatalpol, the structure of which has been shown by UV, PMR, and mass spectroscopy and a comparison of the¹³C NMR spectrum with that of 6-α-L-rhamnopyranosylcatalpol (I). The presence of catalpol and (II) in the plant has been shown by PC and TLC.     

Iridoids from the roots of Valeriana jatamansi and their biological activities

A new iridoid, jatamandoid A (1), and four known analogues (2-5) were isolated from the roots of Valeriana jatamansi. Their structures were elucidated on the basis of extensive spectroscopic analysis (IR, ESI-MS, HR-ESI-MS, 1-D and 2-D NMR). Five compounds were evaluated and compounds 1, 2 and 5 showed moderate neuroprotective effects against MPP(+)-induced neuronal SH-SY5Y cell death.