平榛鞣质成分研究(Ⅲ)

目的研究黑龙江省榛(平榛)Corylusheterophylla的鞣质成分。方法利用大孔树脂柱色谱分离纯化技术反复分离纯化,通过1H-NMR、13C-NMR、FAB-MS、1H-1HCOSY等光谱手段及化学方法对得到的单体成分进行结构鉴定。结果从该植物叶中分离得到3个鞣质成分榛叶鞣质D(Ⅰ)、刺梨素A(Ⅱ)、玫瑰素F(Ⅲ)。结论榛叶鞣质D(Ⅰ)为一新的二聚体鞣质成分。     

Limonoids from the leaves and stems of Toona ciliata

Three new norlimonoids, toonaciliatins A (1), F (6), and G (7), four new limonoids, toonaciliatins B-E (2-5), and five known compounds, 5alpha,6beta,8alpha-trihydroxy-28-norisotoonafolin (8), toonaciliatins H (9) and I (10), febrifugin (11), and khayasin T (12), were isolated from the leaves and stems of Toona ciliata. Compounds 1-3 have an unusual 1-en-3-one system with a 1,11-oxygen bridge, limonoids 11 and 12 have a mexicanolide-type structural frame, and others are typical A,B-seco- (4, 5, 9, and 10) or B-seco-29-nor- (3, 6, 7, and 8) limonoids. Toonaciliatins H (9) and I (10) were obtained for the first time as natural products. The structures were established by extensive spectroscopic methods, particularly 1D and 2D NMR techniques.     

Cytotoxic diacetylenic spiroketal enol ethers from Plagius flosculosus

Three new diacetylenic spiroketal enol ethers named flosculins A (1), B (2), and C (3), along with five known compounds (4-8) of the same structural class, were isolated from the leaves of Plagius flosculosus. The structures were deduced by extensive 1D and 2D NMR spectroscopy and mass spectrometry. All isolated compounds exhibited significant cytotoxic activity against leukemia cells (Jurkat T and HL-60). Compounds 5-8 induced apoptosis in HL-60 cells with corresponding IC(50) values ranging from 4 to 6 microM.     

Tannins and catechin gallate mediate the vasorelaxant effect of Arbutus unedo on the rat isolated aorta

This study examined the vascular effect of Arbutus leaves (aqueous extract) and described the isolation of several fractions responsible for their vasorelaxant activity. The aqueous extract (AE) of leaves was tested on rat aortic rings precontracted with 0.1 microm noradrenaline. At 10(-2) g/L, AE produced an endothelium dependent relaxation of 66% +/- 5%, (n = 8). The leaves of Arbutus were then extracted successively with different solvents and the methanol extract was the most active. When tannins (primarily condensed tannins) were precipitated from the methanol extract, they showed a strong vasorelaxant activity (87% +/- 4%, n = 5), whereas the elimination of tannins in the methanol extract reduced significantly its vasorelaxant activity (42% +/- 8%, n = 8, p < 0.005). The methanol extract was further separated semi-preparatively by reversed-phase HPLC. Four fractions (Fr2, Fr3, Fr4 and Fr6) were the most active and produced 88% +/- 2% (n = 5), 75% +/- 6% (n = 5), 76% +/- 3% (n = 7) and 77% +/- 3% (n = 10) relaxation, respectively. These four fractions mainly correspond to polyphenol compounds. Analysis of Fr6 indicated that this fraction contained catechin gallate. In conclusion, the vasorelaxant activity of Arbutus is likely to be due to polyphenol compounds, primarily condensed tannins and catechin gallate.     

New taxane diterpenoids from the leaves and twigs of Taxus sumatrana

Two new taxoids, taxumairol Q (1) and 13-O-acetyl wallifoliol (2), have been isolated from the leaves and twigs of Taxus sumatrana. Taxuspine F and wallifoliol (10) have been isolated for the first time from the yew T. sumatrana. Seventeen known taxoid diterpenoids have also been isolated. The new derivatives, 9,13-diacetyltaxumairol W (3), 10,13-dibenzoyltaxacustin (4), 7,13-diacetylwallifoliol (5), 7,13-dibenzoylwallifoliol (6), and 7,9-dibenzoyltaxumairol P (7), have been prepared by acylation of a crude mixture of taxoids. All structures were established primarily on the basis of 1D and 2D NMR techniques, including DEPT, COSY, and HMBC experiments, as well as chemical correlation with known compounds. Wallifoliol (10) exhibited significant cytotoxicities against both Hepa 59 T/VGH (human liver carcinoma) and KB (human oral epidermoid carcinoma) tumor cells. Taxuspine F and compound 5 possessed moderate activity against Hepa cells only, while 3, 6, 7, and 10-deacetylbaccatin III showed only marginal activity against Hepa cells.     

A New Phenylpropanol Glycoside from Twigs and Leaves of Rhododendron primulaeflorum

Objective To study the constituents in the twigs and leaves of Rhododendron primulaeflorum. Methods The constituents were separated and purified with chromatographic methods. Their structures were elucidated by spectroscopic methods (1D, 2D NMR, IR, and HR-ESI-MS) and chemical analyses. Results One new phenylpropanol glycoside, 4-hydroxyl-5-methoxyl-phenylpropanol-3-O-β-D-glucopyranoside (1), and its aglycone (2) were successfully isolated from the twigs and leaves of R. primulaeflorum. Conclusion Compound 1 is a new phenylpropanol glycoside. Compounds 1 and 2 are isolated from this plant for the first time.     

Isoterchebulin and 4,6-O-isoterchebuloyl-D-glucose, novel hydrolyzable tannins from Terminalia macroptera

Two new hydrolyzable tannins, isoterchebulin (1) and 4,6-O-isoterchebuloyl-D-glucose (2), together with six known tannins, 3-8, were isolated from the bark of Terminalia macroptera. Their structures were elucidated by extensive 1D and 2D NMR studies, MS, and chemical transformations. Biological activities of all compounds were evaluated against the snail Biomphalaria glabrata, the bacteria Bacillus subtilis and Pseudomonas fluorescens, the nematode Caenorhabditis elegans, and four cancer cell lines (Hep G2, MCF-7/S, MDA-MB-231, and 5637 cells). All compounds except 3 showed antimicrobial activities against B. subtilis (MIC 8-64 microg/mL), whereas only 1 was active against C. elegans (100 microg/mL) and B. glabrata(LC(100) = 60 microg/mL). 3 and 8 were toxic against 5637 cells with LC(50) = 84.66 and 41.40 microM, respectively.     

Phyllanemblinins A-F, new ellagitannins from Phyllanthus emblica.

Six new ellagitannins, phyllanemblinins A-F (1-6), were isolated from Phyllanthus emblica, along with 30 known tannins and related compounds. Their structures were determined by spectral and chemical methods. Phyllanemblinins A (1) and B (2) were confirmed to be ellagitannins having a tetrahydroxybenzofuran dicarboxyl group and a hexahydroxydiphenoyl group, respectively, by chemical synthesis from furosin (8). Phyllanemblinin C (3) has a new acyl group at the glucose 2,4-positions and is structurally related to chebulagic acid. Phyllanemblinins D (4), E (5), and F (6) were found to be positional isomers of neochebuloyl 1(beta)-O-galloylglucose.     

Iridoid glucosides and p-coumaroyl iridoids from Viburnum luzonicum and their cytotoxicity

Four new iridoids glucosides (1-4) and seven new iridoid aglycons (5-11) bearing (E)- or (Z)-p-coumaroyl groups were isolated from a methanol extract of the dried leaves of Viburnum luzonicum collected in Kaoshiung, Taiwan. The structures of the new compounds, named luzonoside A (1), luzonoside B (2), luzonoside C (3), luzonoside D (4), luzonoid A (5), luzonoid B (6), luzonoid C (7), luzonoid D (8), luzonoid E (9), luzonoid F (10), and luzonoid G (11), were elucidated by analysis of spectroscopic data and comparison with values for previously known analogues. Among the iridoids isolated in the present study, glucosides 1 and 2, and their aglycons 5-9, exhibited moderate inhibitory activity against HeLa S3 cancer cells, whereas 3 and 4 showed no cytotoxicity even at 100 microM.     

Constituents from the leaves of Phellodendron amurense var. wilsonii and their bioactivity

Two new dihydroflavonols, phellodensin-A (1) and phellodensin-C (2); three new coumarins, phellodenol-A (3), phellodenol-B (4), and phellodenol-C (5); one new chlorophyll, phellophyll-a (6); and one new phenyllactate, (2R)-sodium 3-phenyllactate (7), in addition to 35 known compounds have been isolated from the leaves of Phellodendron amurense var. wilsonii. The structures of the new compounds were established based on 1D, 2D NMR and mass spectral analyses. The stereochemistry at the C-2, C-3, and C-2' ' positions of new dihydroflavonol 1 was determined by CD spectroscopy. The known compounds were identified by comparison with authentic samples. The antioxidant and antityrosinase activities were also described.     

Triterpenes from Garcia parviflora. Cytotoxic evaluation of natural and semisynthetic friedelanes

Three new friedelane-type triterpenes, 1,2-dehydro-2,3-secofriedelan-3-oic acid (1), 1β-hydroxyfriedelin (2), and 3β-hydroxyfriedelan-23-oic acid (3), and the known compounds friedelin-3,4-lactone (4), acetyl aleuritolic acid (5), 4-hydroxy-5-propionyl-1,3-di-O-methylpyrogallol, elemicin, and (-)-syringaresinol were isolated from the leaves of Garcia parviflora. The structures of 1-3 were elucidated by spectroscopic methods, including 1D and 2D NMR, HREIMS, X-ray, and CD analysis. Some derivatives of 2 (6-14) were prepared via oxidation, reduction, and esterification. The natural triterpenes and the semisynthetic friedelane derivatives were tested for cytotoxic activity against human cancer cell lines U251, PC-3, K562, HCT-15, MCF-7, and SKLU-1. Compound 5 was cytotoxic against U251 cells.     

2-Arylbenzofuran, flavonoid, and tyrosinase inhibitory constituents of Morus yunnanensis

Two novel 2-arylbenzofuran dimers, morusyunnansins A and B (1 and 2), two new biflavonoids, morusyunnansins C and D (3 and 4), two new flavans, morusyunnansins E and F (5 and 6), and four known flavans (7-10) were isolated from the leaves of Morus yunnanensis. Compounds 5-8 showed potent inhibitory effects on mushroom tyrosinase with IC(50) values ranging from 0.12 ± 0.02 to 1.43 ± 0.43 μM.     

Alkaloids from stems and leaves of Stemona japonica and their insecticidal activities

Five new alkaloids, 6beta-hydroxystemofoline (1), 16-hydroxystemofoline (2), neostemofoline (3), protostemodiol (4), and 13-demethoxy-11(S*),12(R*)-dihydroprotostemonine (5), along with 10 known alkaloids, were isolated from stems and leaves of Stemona japonica. Their structures were elucidated by 1D and 2D NMR and other spectroscopic studies. The insecticidal activity of the agonist 16-hydroxystemofoline (2) and antagonist 13-demethoxy-11(S*),12(R*)-dihydroprotostemonine (5) was demonstrated by electrophysiological in vitro tests on the insect nicotinic acetylcholine receptor and by in vivo screenings against relevant agricultural insect pests.     

蒙古栎叶化学成分研究

从斗壳科植物蒙古栎(Quercus mongolica Fisch.)的叶中分离得到七种单体化合物,经鉴定分别为木栓酮(Ⅰ),β-香树脂醇(Ⅱ),正十八醇(Ⅲ),β-谷甾醇(Ⅳ),胡萝卜甙(Ⅴ)和没食子酸(Ⅵ)。化合物Ⅶ的结构待鉴定。     

黄背栎中的黄酮类化学成分研究

 目的研究黄背栎(Quercus pannosa Hand.-Mazz.)中的黄酮类化学成分。方法利用Sephadex LH-20及硅胶等柱色谱技术进行化合物的分离和纯化,根据理化性质、光谱数据对其结构进行鉴定。结果得到5个黄酮类化合物,分别鉴定为(+)-catechin(1),(-)-epicatechin(2),(2R,3R)-(-)-二氢槲皮素3-O-β-D-葡萄糖苷(3),(2R,3R)-(-)-二氢槲皮素3-O-β-D-木糖苷(4),chamaechromone(5)。结论这5个化合物均为首次从黄背栎中分离得到。     

Antimicrobial and anti-inflammatory activity of four known and one new triterpenoid from Combretum imberbe (Combretaceae)

Combretum imberbe is used widely in Africa inter alia for treating bacterial infections. In addition to four known triterpenoids, 1alpha,3beta-dihydroxy-12-oleanen-29-oic (1), 1-hydroxy-12-olean-30-oic acid (2), 3,30-dihydroxyl-12-oleanen-22-one (3), and 1,3,24-trihydroxyl-12-olean-29-oic acid (4), a new pentacyclic triterpenoid (1alpha,23-dihydroxy-12-oleanen-29-oic acid-3beta-O-2,4-di-acetyl-L-rhamnopyranoside) 5 has been isolated through a bioassay-guided procedure from the leaves of Combretum imberbe. The structures of the compounds were elucidated on the basis of 1D and 2D NMR experiments, as well as mass spectrometric data. All compounds isolated had moderate (62 microg/ml) to strong (16 microg/ml) antibacterial activity (MIC values) against Staphylococcus aureus and Escherichia coli, with 1 and 5 being most active. Compounds 1 and 5 also showed very strong inhibition of 3alpha-hydroxysteroid dehydrogenase with an IC(50) of 0.3 microg/ml. Compound 5 indicated a moderate anti-proliferative (GI(50)=16.5 and 13.2 microg/ml) and cytotoxic activity (CC(50)=17.6 micro/ml) against K-562, L-929 and HeLa cell lines, respectively. The results of this study give credence to the ethnomedicinal use of Combretum imberbe and expand our knowledge on the biological activity of its metabolites.     

Isolation and structure elucidation of kadlongilactones C-F from Kadsura longipedunculata by NMR spectroscopy and DFT computational methods

Four new triterpenoids, kadlongilactones C-F (2-5), containing a consecutive hexacyclic [7,7,5,6,6,6] ring system, were isolated from the leaves and stems of Kadsura longipedunculata. In comparison with the NMR data of kadlongilactones A (1) and D (3), a significant phenomena was discovered that ring D of 3 inverted from a half-chair in 1 to a half-boat conformation when the HO-16 group changed from alpha- to beta-orientation. The structures of 2-5 were established on the basis of detailed spectroscopic analysis, and DFT computational methods were applied in the structural validation of compounds 3 and 5. Compounds 1-4 showed significant cytotoxicity against A549, HT-29, and K562 cell lines with IC50 values of 0.49-3.61 microM in vitro.     

Sesquiterpene quinones and related metabolites from Phyllosticta spinarum, a fungal strain endophytic in Platycladus orientalis of the Sonoran Desert

Five new metabolites, (+)-(5 S,10 S)-4'-hydroxymethylcyclozonarone ( 1), 3-ketotauranin ( 3), 3alpha-hydroxytauranin ( 4), 12-hydroxytauranin ( 5), and phyllospinarone ( 6), together with tauranin ( 2), were isolated from Phyllosticta spinarum, a fungal strain endophytic in Platycladus orientalis. The structures of the new compounds were determined on the basis of their 1D and 2D NMR spectroscopic data and chemical interconversions. All compounds were evaluated for inhibition of cell proliferation in a panel of five cancer cell lines, and only tauranin ( 2) showed activity. When tested in a flow cytometry-based assay, tauranin induced apoptosis in PC-3M and NIH 3T3 cell lines.     

New cytotoxic butanolides from Litsea acutivena.

Six new compounds, including one nor-neolignan, dehydroxymethylailanthoidol (1), and five butanolides, litseakolide D (2), litseakolide E (3), litseakolide F (4), litseakolide G (5), and isolincomolide D (6), were isolated from the leaves of Litsea acutivena. Their structures were elucidated from spectral analyses. The butanolides (2-6) showed significant cytotoxic activity against P-388, A549, and HT-29 cell lines in vitro.     

Cytotoxic cucurbitacin constituents from Sloanea zuliaensis

A new cucurbitacin D analogue, 2-deoxycucurbitacin D (1), as well as cucurbitacin D (2) and 25-acetylcucurbitacin F (3) were isolated from Sloanea zuliaensis. Compound 1 was found only in the young leaves of the plant and not in the mature leaves, and its structure was established using spectroscopic means. Compounds 1-3 demonstrated potent cytotoxic activity against breast (MCF-7), lung (H-460), and central nervous system (SF-268) human cancer cell lines.