Two New Coumarins from Fraxinus chinensis Rexb.

The ethanol extract of the stem bark of Fraxinus chinensis Roxb. showed good inhibitory bioactivity against VEGF receptor-1 kinase （IC50：13.8 μg/mL）. In order to find new and bioactive compounds, the chemical constituents of the stem bark of F. chinensis were investigated and two new coumarins, namely 6＇-O-sinapinoyl esculin （compound 1） and 6＇-O-vanillyl esculin （compound 2）, together with eleven known compounds （compounds 3-13） were isolated. The structures of the two new compounds were identified by their physicochemical properties and spectral analysis, particularly one- and two-dimensional nuclear magnetic resonance spectral methods. The known compound, oleuropein （compound 11）, exhibited moderate activity （IC50：（8.7 ± 1.3） μmol/L） to inhibit VEGF receptor- 1 kinase.     

New constituents and antiplatelet aggregation and anti-HIV principles of Artemisia capillaris

Five new constituents including a flavonoid, artemisidin A (1), and four coumarins, artemicapins A (2), B (3), C (4) and D (5), together with 70 known compounds (6-75), have been isolated and characterized from the aerial part of Artemisia capillaris. The structures of these compounds were determined from spectral analyses and/or chemical evidence. Among them, 15 compounds (3, 6, 10, 18. 30-32, 38-41, 44, 45, 51, and 55) showed antiplatelet aggregation activity and three compounds (10, 17, and 51) demonstrated significant activity against HIV replication in H9 lymphocytic cells.     

Phenolic derivatives with free-radical-scavenging activities from Ixeridium gracile (DC.) Shih

Phytochemical investigation of the Tibetan medicinal plant Ixeridium gracile resulted in the isolation and identification of twelve flavonoids and two coumarins, compounds 1-14, the dimeric '2alpha,3alpha-epoxy-5,7,3',4'-tetrahydroxyflavan-(4beta-->8)-epicatechin' (1) being a new constituent. The free-radical-scavenging potentials of different extract fractions as well as of the pure compounds towards the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical were evaluated, and are discussed in terms of structure-activity relationship (SAR). The flavonoids were found to be the major constituents contributing to the free-radical-scavenging activity of I. gracile, but the high concentration of coumarins additionally contributed to the observed activity.     

Coumarins and psoralens in grapefruit peel oil

Four coumarins, four psoralens and two methoxyflavones were isolated and identified from the peel oil of grapefruit. Five of these compounds are reported as constituents of grapefruit oil for the first time, one of which, 5[(3,7-dimethyl-6-epoxy-2-octenyl) oxy]psoralen is a new natural product.     

Chemistry of Zataria multiflora (Lamiaceae)

The hexane soluble part of Zataria multiflora afforded three new aromatic constituents which include two p-cymene derivatives: multiflotriol (1), multiflorol (2) and an aromatic ester of p-hydroxy benzoic acid (3). In addition to these three new compounds, three known compounds, dihydroxyaromadendrane, luteolin and alpha-tocopherolquinone, have also been isolated for the first time from the same source. The structures of all the isolated constituents were elucidated by means of spectroscopic methods including 2D-NMR techniques.     

Lignans and Terpenoids from the Leaves of Schisandra chinensis

Fifteen constituents, including one new lignan (schisandroside E) and one new terpenoid (schisandenoid A) as well as nine known lignans and four known terpenoids, were isolated from Schisandra chinensis leaves. The structures of schisandroside E and schisandenoid A were established by entirely meticulous spectroscopic analysis (NMR, MS, CD, IR and UV). All compounds were tested for cytotoxicity against MGC‐803, Caco‐2 and Ishikawa cell lines. Some compounds showed strong cytotoxicity against these three cancer cell lines with IC₅₀<1 μm .     

Coumarins from the heartwoods of Mansonia gagei Drumm

Three coumarins and three known mansonones were isolated from the heartwood of Mansonia gagei Drumm. The structures of the three coumarins were elucidated as 3,8-dimethyl-5-isopropyl-6-methoxycoumarin (mansonrin A) 3,8-dimethyl-5-isopropyl-6-hydroxycoumarin (mansorin B) and 2,3-dihydro-3,6,9-trimethyl naphtho[1,8-bc]pyran-7-oxa-8-one (mansorin C) by analyses of physical properties and spectroscopic data. The cytotoxicity of the isolated compounds against brine shrimp Artemia salina Linn. was also evaluated.     

Scaphopetalone and scaphopetalumate,a lignan and a triterpene ester from Scaphopetalum thonneri

From the methanol extract of the stem bark of Scaphopetalum thonneri, two new compounds, including one lignan, named scaphopetalone, one new ester of ferulic acid, named scaphopetalumate were isolated together with three known compounds including: two coumarins (scopoletin and scopolin), and one pentacyclic triterpene (oleanolic acid). The structure of the new compounds were elucidated by means of spectroscopic analyses.     

Natural products from Tolpis barbata (L.) Gaertn. (Asteraceae,Cichorieae)

One sesquiterpene lactone – 9α-hydroxy-3-deoxyzaluzanin C, three benzopyrans: desmethoxyencecalin (6-acetyl-2,2-dimethylchromene), desacetylripariochromen B and 6-(1-hydroxyethyl)-2,2-dimethylchromene, one coumarin – scopoletin and two eugenol derivatives were isolated from the roots of Tolpis barbata (L.) Gaertn, hitherto unexamined species. In the extract from aerial parts of the plant, five known phenolic compounds, namely: esculin, esculetin, chlorogenic acid (5-CQA), luteolin 7-O-glucoside and 3,5-dicaffeoylquinic acid (3,5-DCQA) were identified as major constituents. Except for the two coumarins – scopoletin and esculetin, which were previously obtained from Tolpis webbii Sch.Bip. and T. proustii Pit., the isolated and identified compounds have not been previously reported as constituents of Tolpis spp. Though benzopyrans were found in numerous species of the Asteraceae, their occurrence in the tribe Cichorieae has not been demonstrated before.     

Suppressive effects of coumarins from Mammea siamensis on inducible nitric oxide synthase expression in RAW264.7 cells

A methanol extract of the flowers of Mammea siamensis (Calophyllaceae) was found to inhibit nitric oxide (NO) production in lipopolysaccharide-activated RAW264.7 cells. From the extract, two new geranylated coumarins, mammeasins A (1) and B (2), were isolated together with 17 known compounds including 15 coumarins. The structures of 1 and 2 were determined on the basis of their spectroscopic properties as well as of their chemical evidence. Among the isolates, 1 (IC(50)=1.8μM), 2 (6.4μM), surangins B (3, 5.0μM), C (4, 6.8μM), and D (5, 6.2μM), kayeassamins E (7, 6.1μM), F (8, 6.0μM), and G (9, 0.8μM), mammea A/AD (11, 1.3μM), and mammea E/BB (16, 7.9μM) showed NO production inhibitory activity. Compounds 1, 9, and 11 were found to inhibit induction of inducible nitric oxide synthase (iNOS). With regard to mechanism of action of these active constituents (1, 9, and 11), suppression of STAT1 activation is suggested to be mainly involved in their suppression of iNOS induction.     

Coumarins from the heartwoods of Mansonia gagei Drumm.

Three coumarins and three known mansonones were isolated from the heartwood of Mansonia gagei Drumm. The structures of the three coumarins were elucidated as 3,8-dimethyl-5-isopropyl-6-methoxycoumarin (mansonrin A) 3,8-dimethyl-5-isopropyl-6-hydroxycoumarin (mansorin B) and 2,3-dihydro-3,6,9-trimethyl naphtho[1,8-bc]pyran-7-oxa-8-one (mansorin C) by analyses of physical properties and spectroscopic data. The cytotoxicity of the isolated compounds against brine shrimp Artemia salina Linn. was also evaluated.     

Cancer chemopreventive constituents from Melicope lunu-ankenda

A study of the chemical constituents obtained from twigs of Melicope lunu-ankenda (Gaertn.) T.G. Hartley (Rutaceae) led to the isolation and structure elucidation of two new coumarins, 7-(4-hydroxy-3-methylbutanoxy) coumarin and 7-(3-methyl-4-carboxybutanoxy) coumarin methyl ester, named melilunumarin A (1) and melilunumarin B (2), respectively. A new benzaldehyde derivative, 3,4-dihydro-3,4-dihydroxy-2,2-dimethyl-2H-1-benzopyran-6-carboxaldehyde, named melilunumane (6), was also isolated and characterized, as well as five previously reported compounds, 6-deoxyhaplopinol (3), marmesin (4), umbelliferone (5), kokusaginine (7) and evolitrin (8). Among the five isolated coumarins, melilunumarin A (1), 6-deoxyhaplopinol (3) and marmesin (4) exhibited significant inhibitory activity towards Epstein-Barr virus early antigen activation induced by 12-O-tetradecanoylphorbol 13-acetate in Raji cells.     

Quinochalcones and flavonoids from fresh florets in different cultivars of Carthamus tinctorius L

The flavonoid constituents in fresh florets of the three distinctive cultivars of Carthamus tinctorius L. were purified and identified to investigate flavonoid biosynthesis in the petals. From the orange flower of cv. Kenba (K.), four new compounds, anhydrosafflor yellow B (1), two kaempferols, 9 and 13, and a quercetin, 17, were isolated, as well as the twelve known compounds, and their structures were determined by spectral data, chemical reactions, and molecular mechanics calculations. From the yellow flower of cv. Ogon-hanagasa (O.), two flavonols and two quinochalcones, and from the white flower of cv. Shiro-bana (S.), three flavonois were isolated. These compounds were the same as those contained in cv. K. To compare the flavonoid constituents among the three cultivars, crude extracts were analyzed by a LC/PDA/MS system. In cv. K., six quinochalcones and eleven flavonols were identified. In cv. O., three quinochalcones and nine flavonols were identified, but the red pigment, carthamin (4), and its precursor, precarthamin (3), were not detected. In cv. S., four flavonols without a 6-hydroxyl group were identified. On the basis of a comparative study on the constituents among these three cultivars, a possible biosynthetic pathway to form quinochalcones via the intermediate, pentahydroxychalcone (19), is proposed.     

紫菀属化学成分及药理活性研究进展

紫菀属所含化学成分主要是三萜皂甙 ,此外还含其它萜类、肽类、香豆素、甾醇等 ;其中一些成分具有抗瘤 ,抗菌 ,消炎等活性。本文对其近 2 0多年来国内外学者分离到的化学成分及其药理活性的研究结果作一综述 ,为该属植物资源的进一步研究和开发提供参考。     

Armenin and isoarmenin--two prenylated coumarins from the aerial parts of Artemisia armeniaca

The reversed-phase (RP) preparative HPLC analyses of the MeOH extract of the aerial parts of Artemisia armeniaca yielded four prenylated coumarins, 7-hydroxy-8-(4-hydroxy-3-methylbutoxy)coumarin (named armenin), 8-hydroxy-7-(4-hydroxy-3-methylbutoxy)coumarin (named isoarmenin), lacarol, and deoxylacarol, together with five other compounds, including three flavonoid glycosides, quercetin 3-O-β-D-glucopyranoside, rutin, and kaempferol 3-O-β-D-glucopyranoside, and chlorogenic acid, and tryptophan. (10E,12Z)-9-Hydroxyoctadeca-10,12-dienoic acid (β-dimorphecolic acid) was isolated from the CH(2)Cl(2) extract. Armenin and isoarmenin were new coumarins. Structures of all compounds were determined by spectroscopic means, including UV, MS, 1D- and 2D-NMR. The in vitro free-radical-scavenging property of the extracts and isolated compounds was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay.     

旱前胡的化学成分

从云南产早前胡(Ligusticum daucoides Franch.)(伞形科)根的脂溶性部分分离了11个化合物,分别为香豆素化合物:columbianadin,isoedultin,archangelicin,旱前胡甲素(daucoidin A),旱前胡乙素(dsucoidin B),佛手柑内酯(bergapten),非香豆素化合物:falcarindiol(7),阿魏酸(ferulic acid),蜡酸(cerotic acid),β-谷甾醇(β-sitosterol),胡萝卜甙(daucosterol)。其中,化合物4和5是新的香豆素化合物,经化学方法及光谱测定,证明其结构为:4是3′去乙酰基isoedultin,即:2′(S)-(1″,1″-二甲基,1″-当归酰氧基)-3′(R)-羟基-角型二氢呋喃香豆素[2′(S)-(1″,1″-dimethvl,1″-angelovloxv)—3′(R)-hydroxy angular dihydrofuranocoumarin];5是2′-(1″-甲基,1″-羟基,1″-当归酰氧亚甲基)-角型二氢呋喃香豆素[2′-(1″-methyl,1″-hydroXy,1″-angeloyloxy-methylene)angular dihydrofuranocoumarin]。     

Cytotoxic cardiac glycosides and coumarins from Antiaris toxicaria

Eight new cardiac glycosides/aglycones (antiaritoxiosides A–G, 1–7, and antiarotoxinin B, 8), two new coumarins (anticarins A–B, 41–42), and two new flavanones (antiarones L–K, 43–44) were isolated from trunk bark of Antiaris toxicaria together with 53 known compounds. The new structures were established by extensive analysis of spectroscopic data. Compound 1 (10-carboxy and 3α-hydroxy) and compounds 3–6 (10-hydroxy) contain unique substituents that are rarely found in cardiac glycosides. The cytotoxic effects of isolated compounds against ten human cancer cell lines, KB, KB-VIN, A549, MCF-7, U-87-MG, PC-3, 1A9, CAKI-1, HCT-9 and S-KMEL-2, were tested using the sulforhodamine B assay. Five compounds (12, 16, 20, 22, and 31) showed significant cytotoxicity against all ten cancer cell lines, with notable potency at the ng/mL level against some cell lines, which merits further development as clinical trial candidates.     

Two new sesquiterpene coumarins from the seeds of Ferula sinkiangensis

Two new sesquiterpene coumarins, namely, sinkiangenorin F (1) and 8-O-acetyl sinkiangenorin F (2) were isolated from the seeds of Ferula sinkiangensis. The structures of the new compounds, including the relative stereochemistry and the absolute configuration were elucidated through extensive spectroscopic methods. The two compounds were tested against the K562, HeLa, and AGS human cancer cell lines and showed cytotoxic activities with 50% inhibitory concentration values between 27.1 and 62.7 μM.     

New monoterpenes and benzylbutanoic acid from snowbell (Styrax japonica) honey and their quantitative analysis by LC-ESI-Q-TOF-MS/MS

Honey varies depending on plant origin and environmental conditions. Chemical constituents can be used to determine the origins, characteristics, and storage period of a specific honey. Styrax japonica (snowbell) honey has excellent flavor, but very few studies have been carried out on its chemical constituents. Therefore, the present study was aimed to identify chemical constituents containing in snowbell honey and to screen candidate marker compounds for predicting the storage period of snowbell honey using the identified compounds. Twelve compounds including three new compounds were purified and isolated from the snowbell honey. Three new compounds were elucidated as 1α,3β,5β-bornetriol, 7-hydroxy-2,2,6-trimethyl-1-oxaspiro[2.5]oct-5-en-4-one, and 2-benzyl-2,3-dihydroxybutanoic acid, based on ESI-MS and NMR experiments. 6,7-Dihydroxylinalool and 6,7-dihydroxygeraniol isolated as known compounds in this study were identified for the first time in snowbell honey as well as in other honeys. The isolated compounds were qualified and quantified by LC-ESI-Q-TOF-MS/MS analysis. All compounds were detected in snowbell honeys of different production years. The levels of tyrosol, 7-hydroxy-2,2,6-trimethyl-1-oxaspiro[2.5]oct-5-en-4-one, and (–)-dihydroxyphaseic acid were lower in snowbell honey with long storage period than in short storage period, which is suggested to be used as candidate marker compounds for predicting the storage period of snowbell honey.