牛奶菜中黄酮类成分的研究

从牛奶菜(Marsdenia sinensis Hemsl)根中分离得到6个黄酮类化合物,经光谱分析确定其结构为:芹菜素(1),(2S)-柚皮素(2),木犀草素(3),异牡荆素(4),8-C-β-D-Glucopyranosyl apigeninidin(5),5,7-二羟基色原酮(6)。所有化合物均为首次从该植物中分离得到,同时对分离得到的单体化合物进行细胞毒活性测试,化合物1～5均表现出较强的细胞毒活性。     

艾纳香化学成分的研究

从艾纳香(Blumea balsamifera DC.)中分离得到12个化合物,通过理化性质和波谱数据分析分别鉴定为;商路素(1),花椒油素(2),2,4-二羟基-6-甲氧基苯乙酮(3),5,7-二羟基色原酮(4),金丝桃苷(5),异槲皮苷(6),3′,4′,5,7-四羟基-3-甲氧基黄酮(7),槲皮素(8),槲皮素-3′-甲氧基-3-O-β-D-半乳吡喃糖苷(9),4′,5,7-三羟基-3,3′-二甲氧基黄酮(10),3,5,7-三羟基-3′,4′-二甲氧基黄酮(11),木犀草素(12).其中,化合物3-7和9- 11为首次从该属植物中分离得到.     

Three new phenolic acid derivatives from Oenothera biennis

Three new phenolic acid derivatives, 1-methyl glyceric acid-2-vanillic acid ether (1), methyl 2-hydroxy-6-(3-methoxy-3-oxoprop-1-en-2-yloxy) benzoate (2), methyl 2-hydroxy-6-(1-Carboxyvinyloxy) benzoate (3) and five known compounds namely 4-hydroxymellein (4), mellein methyl ether (5), 2-methyl-5,7-dihydroxychromone (6), latifolicinin C (7) and oresbiusin A (8) were isolated from Oenothera biennis L. The structures of these secondary metabolites were elucidated using different spectroscopic techniques, including ¹H, ¹³C NMR, HR-ESI-MS, ECD and comparison with published data.     

5,7-Dihydroxychromones and 8-hydroxytetrahydrochromones from Horsfieldia irya

Wood of Horsfieldia irya contained 2-n-nonyl- and 2-(6-phenylhexyl)-5,7-dihydroxychromone, 2-n-nonyl-8-hydroxy- and 2-(6-phenylhexyl)-8-hydroxy-5,6,7,8-tetrahydrochromone as well as dihydrocubebin.     

Anti-diabetic properties of Daphniphyllum macropodum fruit and its active compound

We evaluated in vitro anti-diabetic activities of 497 native plants of Jeju Island (South Korea) by measuring the induction of adipocyte differentiation. Among the plants, Daphniphyllum macropodum fruit extract (DME) had the highest peroxisome proliferator-activated receptor γ (PPARγ) agonist activity and was therefore selected as a potential source of anti-diabetic agents. To elucidate the active components of DME, constituent compounds were purified and their effects on the adipocyte differentiation were studied. Using activity-guided fractionation, four compounds were isolated from DME and their adipogenic effects were evaluated. Among the compounds isolated, 5,7-dihydroxychromone potently induced the differentiation of mouse 3T3-L1 preadipocytes. DME and 5,7-dihydroxychromone increased PPARγ and liver X receptor α (LXRα) mRNA expression levels. To determine whether the adipogenic effects we observed might affect serum glucose levels, we undertook in vivo experiment using streptozotocin-/high-fat diet-induced type 2 diabetes mouse model. DME supplementation reduced serum glucose, total cholesterol, and triacylglycerol levels in diabetes mice. These results suggest that DME may be useful for the prevention and treatment of type 2 diabetes mellitus. Moreover, it was proposed that 5,7-dihydroxychromone isolated from DME is one of the active compounds that may contribute to regulate blood glucose levels.     

Pyrones from the bark of Garcinia conrauana: Conrauanalactone,a novel C20 derived α-pyrone

Conrauanalactone has been isolated from the bark of Garcinia conrauana Engl. (Guttiferae) and identified, on the basis of spectral and chemical evidence, as 4-hydroxy-6-pentadecyl- 2-pyrone. Minor constituents of the bark have been identified as 5,7-dihydroxychromone and eriodictyol.     

Antibacterial and antifungal flavanones from Eysenhardtia texana

An activity-guided fractionation of a methanol-dichloromethane extract obtained from the aerial parts of Eysenhardtia texana led to the isolation of two novel antibacterial and antifungal flavanones together with a known flavanone. Their structures were established as 4',5,7-trihydroxy-8-methyl-6-(3-methyl-[2-butenyl])-(2S)-flavanone, 4',5,7-trihydroxy-6-methyl-8-(3-methyl-[2-butenyl])-(2S)-flavanone and 4',5-dihydroxy-7-methoxy-6-(3-methyl-[2-butenyl])-(2S)-flavanone on the basis of their UV, 1D and 2D-NMR spectra.     

Three isoflavanones with cannabinoid-like moieties from Desmodium canum

Three further derivatives of 5,7,2',4'-tetrahydroxy-6-methyl isoflavanone have been isolated from the root extract of Desmodium canum and assigned the structures 2,3-dihydro-5,7-dihydroxy-6-methyl-3-(1a,2,3,3a,8b,8c-hexahydro-6-hydroxy-1,1,3a-trimethyl-1H-4-oxabenzo[f]cyclobut[c,d]inden-7-yl)-4H-1-benzopyran-4-one (1) 2,3-dihydro-5,7-dihydroxy-6-methyl-3-(6a,7,8,10a-tetrahydro-3-hydroxy-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-2-yl)-4H-1-benzopyran-4-one (2) 2,3-dihydro-5,7-dihydroxy-6-methyl-3-(3-hydroxy-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-2-yl) 4H-1-benzopyran-4-one (3). The three compounds and the previously isolated chromene 4 all derive from the geranylated precursor 5 by a series of cannabinoid-like oxidative rearrangements.     

Homoisoflavonoids from Ophiopogon japonicus Ker-Gawler

From the ethyl acetate extract of the tuberous roots of Ophiopogon japonicus (Liliaceae) eight known and five new homoisoflavonoidal compounds were isolated. The new compounds are 5,7-dihydroxy-8-methoxy-6-methyl-3-(2'-hydroxy-4'-methoxybenzyl)chroman-4-one (1), 7-hydroxy-5,8-dimethoxy-6-methyl-3-(2'-hydroxy-4'-methoxybenzyl)chroman-4-one (2), 5,7-dihydroxy-6,8-dimethyl-3-(4'-hydroxy-3'-methoxybenzyl)chroman-4-one (3), 2,5,7-trihydroxy-6,8-dimethyl-3-(3',4'-methylenedioxybenzyl)chroman-4-one (4) and 2,5,7-trihydroxy-6,8-dimethyl-3-(4'-methoxybenzyl)chroman-4-one (5). Their structures have been elucidated by mass and NMR spectroscopy. Compounds 4 and 5 are the first isolated homoisoflavonoids with a hemiacetal function at position 2.     

青龙衣中细胞毒活性成分的研究

利用各种化学及色谱技术从青龙衣中分离得到11个化合物,通过理化性质和波谱学手段分别鉴定为2-羟基-1,4-萘醌(2-hydroxy-1,4-naphthoquinone,1)、5-羟基-1,4-萘醌(5-hydroxy-1,4-naphthoquinone,2)、2,5-二羟基-1,4-萘醌(2,5-dihydroxy-1,4-naphthoquinone,3)、3,5-二羟基-1,4-萘醌(2,5-dihydroxy-1,4-naphthoquinone,4)、5,8-二羟基-1,4-萘醌(2,5-dihydroxy-1,4-naphthoquinone,5)、5-甲氧基-1,4-萘醌(5-methoxy-1,4-naphthoquinone,6)、5,7-二羟基色原酮(5,7-dihydroxychromone,7)、异香草酸(isovanillic acid,8)、没食子酸(gallic acid,9)、β-谷甾醇(β-sitosterol,10)和β-胡萝卜苷(β-daucosterol,11)。化合物3、4、6～8为首次从该属植物中分离得到,化合物1为首次从该植物中分离得到。细胞毒活性测试结果表明,化合物3和4对HepG2细胞表现出强的抑制作用,IC50值分别为5.0±0.6μmol/L和7.0±0.5μmol/L;2和5能显著抑制HL-60细胞的增殖,IC50值分别为9.3±1.2μmol/L和2.3±0.2μmol/L。     

In vitro inhibition of prostaglandin H synthase by compounds from the exocrine secretions of lace bugs

1. Selected lace bug-derived and related compounds were shown to be in vitro inhibitors of mammalian and insect derived prostaglandin H synthase. 2. Two compounds, 2,6-dihydroxyacetophenone and 2,4,6-trihydroxyacetophenone, were significantly better inhibitors of prostaglandin synthesis than aspirin, whereas 2-nonyl-5,7-dihydroxychromone and 1-(2,6-dihydroxyphenyl) dodecan-1-one were equivalent to aspirin. 3. 2,4-Dihydroxyacetophenone was less effective in inhibiting the prostaglandin H synthase and 2-nonyl-5-hydroxychromanone showed no inhibition. 4. Three compounds, 2,6-dihydroxyacetophenone, 2,4,6-trihydroxyacetophenone and 1-(2,6-dihydroxyphenyl) dodecan-1-one were equal to aspirin in PSI inhibition with fat body preparations of the American cockroach Periplaneta americana L.     

Anti-oxidative compounds in barley tea

Five phenolic compounds, p-hydroxyacetophenone, 5,7-dihydroxychromone, naringenin, quercetin, and iso-americanol A, were found first time in the barley tea, together with the known compounds, p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, p-hydroxybenzoic acid, vanillic acid, and p-coumaric acid. The anti-oxidative properties were evaluated by measuring their peroxynitrite-scavenging activities. Among these compounds, 3,4-dihydroxybenzaldehyde, p-coumaric acid, quercetin, and isoamericanol A showed stronger activities than that of BHT (butylated hydroxytoluene) at 400 microM.     

Antibacterial and cytotoxic activity of prenylated bicyclic acylphloroglucinol derivatives from Hypericum amblycalyx

Two new bicyclic acylphloroglucinol derivatives, hypercalyxone A (1-[5,7-dihydroxy-2-methyl-3-(3-methyl-but-2-enyl)-2-(4-methyl-pent-3-enyl)-chroman-8-yl]-2-methyl-propan-1-one, 1) and B (1-[5,7-dihydroxy-2-methyl-3-(3-methyl-but-2-enyl)-2-(4-methyl-pent-3-enyl)-chroman-8-yl]-2-methyl-butan-1-one, 2), have been isolated from the petroleum ether extract of the aerial parts of Hypericum amblycalyx, together with two further compounds (1-[5,7-dihydroxy-2-methyl-2-(4-methyl-pent-3-enyl)-chroman-8-yl]-2-methyl-propan-1-one, 3 and 1-[5,7-dihydroxy-2-methyl-2-(4-methyl-pent-3-enyl)-chroman-8-yl]-2-methyl-butan-1-one, 4), which have been described only as semi-synthetic products. In addition, the known triterpene lup-20(29)-en-3-one was obtained. Structure elucidation was based on 1D and 2D NMR studies, as well as on data derived from mass spectrometry. The four acylphloroglucinol derivatives were evaluated for their cytotoxic and antibacterial activity. All compounds showed moderate cytotoxic activity against KB and Jurkat T cancer cells. Especially compounds 3 and 4 exhibited a strong antibacterial activity against different Gram-positive strains.     

Relationship between pKa of 8-quinolinol derivatives and a π-donor ability of the 8-quinolinolato oxygen in linear nitrosylruthenium(II) complexes

The relationship between the pK_a of 8-quinolinol derivatives {8-quinolinol (Hqn), 2-methyl- (H2-Meqn), 2,4-dimethyl- (H2,4-diMeqn), 5-chloro- (H5-Clqn) and 5,7-dichloro-8-quinolinols (H5,7-diClqn)} and a π-donor ability of the 8-quinolinolato oxygens has been investigated by the identification of the structures of the major products, [RuCl(QN)(QN′)NO] (HQN=8-quinolinol derivative; HQN′=different 8-quinolinol derivatives), obtained by the reaction of [RuCl₃(QN or QN′)NO]⁻ with HQN′ or HQN. The results obtained clearly showed that the oxygen of the 8-quinolinol derivative that has a higher pK_a predominantly coordinates in the trans position to the NO ligand and is a better π-electron donor. The order of the π-electron donor ability for the oxygen of the 8-quinolinol derivatives is as follows: H2-Meqn≥H2,4-diMeqn>Hqn≥H5-Clqn>H5,7-diClqn, almost agreeing with the magnitude of the pK_a values of the corresponding 8-quinolinols. The structures of cis-1 [RuCl(5,7-diClqn)₂NO] and cis-1 [RuCl(5,7-diClqn)(2-Meqn)NO] were determined by X-ray diffraction.     

Homoisoflavanones from Disporopsis aspera

From cytotoxic extracts of the roots of Disporopsis aspera Engl. (Liliaceae) a homoisoflavanone, disporopsin (3-(2',4'-dihydroxy-benzyl)-5,7-dihydroxy-chroman-4-one) (1) and three rare methyl-homoisoflavanones, 3-(4'-hydroxy-benzyl)-5,7-dihydroxy-6-methyl-chroman-4-one (2), 3-(4'-hydroxy-benzyl)-5,7-dihydroxy-6,8-dimethyl-chroman-4-one (3) and 3-(4'-hydroxy-benzyl)-5,7-dihydroxy-6-methyl-8-methoxy-chroman-4- one (4) along with five other known compounds, N-trans-feruloyl tyramine (5), adenine (6), 5-(hydroxymethyl)-2-furfural (7), beta-sitosterol (8) and beta-sitosteryl glucopyranoside (9) were isolated. The structures of compounds 1-2 were elucidated by spectral data (1, 2-D NMR and EIMS). The four homoisoflavanones (1-4) were found to be cytotoxic against a series of human cancer cell lines (HCT15, T24S, MCF7, Bowes, A549 and K562) with IC(50) ranging from 15 to 200 microM. Possible biosynthesis routes for homoisoflavonoids (1-4) are discussed.     

Anthraquinones from the fruits of Vismia laurentii

Phytochemical study of the fruits of Vismia laurentii resulted in the isolation of five structurally related compounds. Three of them are constituents, namely, laurentiquinone A (1) (methyl 1,6,8-trihydroxy-3-methyl-7-(3-methylbut-2-enyl)-9,10-dioxo-9,10-dihydroanthracene-2-carboxylate), laurentiquinone B (2) (methyl 5,7-dihydroxy-2,2,9-trimethyl-6,11-dioxo-6,11-dihydro-2H-anthra[2,3-b]pyran-8-carboxylate) and laurentiquinone C (3) (methyl 9-(ethanoyloxymethyl)-5,7-dihydroxy-2,2-dimethyl-6,11-dioxo-6,11-dihydro-2H-anthra[2,3-b]pyran-8-carboxylate) and two are known compounds, emodin (4) and isoxanthorin (5). Their structures were elucidated by spectroscopic means. Crude extracts of hexane and EtOAc showed anti-plasmodial activity against the W2 strain of Plasmodium falciparum.     

高速逆流色谱法分离制备花生壳中的黄酮类化合物

应用高速逆流色谱法首次从花生壳中分离制备了3种黄酮类化合物。以正己烷-乙酸乙酯-甲醇-水-冰醋酸(5:3:3.5:5:0.25,v/v)为两相溶剂系统,在主机转速800 r/min、流速2 mL/min、检测波长275 nm条件下进行分离制备,纯度用HPLC法测定,各化合物结构经质谱和核磁共振氢谱、碳谱鉴定。结果表明,100 min内从70 mg花生壳粗提物中一步分离制备得到木犀草素11.0 mg,香叶木素2.2 mg,5,7-二羟基色原酮5.2 mg,其纯度均达96.0%以上。利用该方法可以对花生壳中的黄酮类化合物进行快速的分离和纯化。     

Anti-Oxidative Compounds in Barley Tea

Five phenolic compounds, p-hydroxyacetophenone, 5,7-dihydroxychromone, naringenin, quercetin, and iso-americanol A, were found first time in the barley tea, together with the known compounds, p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, p-hydroxybenzoic acid, vanillic acid, and p-coumaric acid. The anti-oxidative properties were evaluated by measuring their peroxynitrite-scavenging activities. Among these compounds, 3,4-dihydroxybenzaldehyde, p-coumaric acid, quercetin, and isoamericanol A showed stronger activities than that of BHT (butylated hydroxytoluene) at 400 μM.     

Toddanol and toddanone,two coumarins from Toddalia asiatica

Two new constituents isolated from the roots of Toddalia asiatica and designated as toddanol and toddanone have been characterized as 5,7-dimethoxy-6-(2-hydroxy-3-methylbut-3-enyl)coumarin (1) and 5,7-dimethoxy-6-(3-methyl-2-oxobutanyl)coumarin (3), respectively, by spectral analysis and interconversion experiments.     

Isolation, Purification, and Identification of 2-(p-Hydroxyphenoxy)-5, 7-Dihydroxychromone: A Fungal-Induced Phytoalexin from Cassia obtusifolia

A single phytoalexin was isolated and purified from 12- to 14-day-old leaves of Cassia obtusifolia L. inoculated with Alternaria cassiae Jurair & Khan. The structure was elucidated by ¹H- and ¹³C-nuclear magnetic resonance and mass spectrometry as 2-(p-hydroxyphenoxy)-5,7-dihydroxychromone. The compound was shown to be derived in part from phenylalanine. Radial growth of A. cassiae was inhibited 50% by the compound at 0.3 millimolar. This moderate toxicity is compensated for by the relatively high levels (3 millimolar) accumulated. Phenoxychromones have been previously reported only as constitutive secondary metabolites in Artemisia capillaris Thunb., in which their function is unknown.