Tunichrome sp-1: new pentapeptide tunichrome from the hemocytes of Styela plicata

A modified pentapeptide has been isolated from the hemocytes of the ascidian Styela plicata. The structure of the peptide was determined by Edman sequence analysis, mass spectrometry, and NMR spectroscopy with the stereochemistry assigned by acid hydrolysis followed by both (a) GC-MS of the volatile amino acid derivatives on a chiral column and (b) ultrasensitive detection of fluorescent diasteromeric derivatives of the component amino acids after reversed-phase HPLC. The peptide L-DOPA-L-DOPA-Gly-L-Pro-dcdeltaDOPA (where DOPA = 3,4-dihydroxyphenylalanine and dcdeltaDOPA = decarboxy-(E)-alpha,beta-dehydro-3,4-dihydroxyphenylalanine) we designate as tunichrome Sp-1.     

槐耳发酵液乙酸乙酯部位化学成分的研究

目的探究槐耳Trames robiniophila Murrll.发酵液乙酸乙酯部位的化学成分。方法槐耳发酵液乙酸乙酯部位采用硅胶、ODS、HPLC进行分离纯化,根据理化性质及波谱数据鉴定所得化合物的结构。结果从中分离得到16个化合物,分别鉴定为尿嘧啶(1)、3,4-二羟基苯甲酸甲酯(2)、3,4-二羟基苯甲酸(3)、1-苯基-1,2-丙二醇(4)、环(亮氨酸-脯氨酸)(5)、环(苯丙氨酸-丙氨酸)(6)、环(4-S-羟基-R-脯氨酸-R-异亮氨酸)(7)、环(苯丙氨酸-甘氨酸)(8)、环(D-羟脯氨酸-L苯丙氨酸)(9)、环(L苯丙氨酸-L羟脯氨酸)(10)、对羟基苯甲酸甲酯(11)、对羟基苯甲酸(12)、对羟基苯甲醛(13)、3,4-二羟基苯甲酸乙酯(14)、环(丙氨酸-异亮氨酸)(15)、环(D-亮氨酸-反-4-羟基-L-脯氨酸)(16)。结论所有化合物均为首次从该真菌发酵液中分离得到。     

Caffeic acid improves the bioavailability of l‐dopa in rabbit plasma

The impacts of caffeic acid (3,4‐dihydroxycinnamic acid, CA) on the pharmacokinetics of levodopa (L‐dopa) were studied in rabbits. A single dose of 5/1.25 mg·kg^?1 l ‐dopa/carbidopa was administered alone or was co‐administered with three different doses of caffeic acid (2.5, 5, and 10 mg·kg^?1), or a single dose of 5 mg·kg^?1 caffeic acid was administered alone via an intramuscular route to six rabbits each in a crossover treatment protocol. Plasma levels of l ‐dopa, 3‐O‐methyldopa (3‐OMD), caffeic acid, and ferulic acid were determined and subsequently used to calculate their pharmacokinetic parameters. The results indicated that caffeic acid administered at a dose of 10 mg·kg^?1 decreased about 22% of the peripheral formation of 3‐OMD and about 31% of the C_max of 3‐OMD. In addition, the metabolic ratios (MR, AUC of 3‐OMD/AUC of L‐dopa) decreased by about 22%. Results also indicated that caffeic acid significantly decreased the proportion of 3‐OMD (p < 0.05). In contrast, the parameters of neither caffeic acid nor ferulic acid were significantly affected by l ‐dopa/carbidopa. In conclusion, caffeic acid at a dose of 10 mg·kg^?1 can significantly affect the COMT metabolic pathway of L‐dopa. Copyright © 2009 John Wiley & Sons, Ltd.     

New pyranonaphthoquinone and pyranonaphthohydroquinone from the roots of Pentas longiflora

Several quinone type compounds were isolated from the hexane, dichloromethane, and ethyl acetate extracts of the roots of Pentas longiflora. The hexane extract afforded two new compounds, [(3alpha,3'alpha,4beta,4'beta)-3,3']-dimethoxy-cis-[4,4'-bis(3,4,5,10-tetrahydro-1H-naphtho[2,3-c]pyran)]-5,5',10,10'-tetraone (1) and cis-3,4-dihydroxy-3,4-dihydromollugin (2), together with six known compounds, namely, pentalongin, mollugin, trans-3,4-dihydroxy-3,4-dihydromollugin, methyl-2,3-epoxy-3-prenyl-1,4-naphthoquinone-2-carboxylate, tectoquinone, and 3-hydroxymollugin. From the dichloromethane extract were isolated the three known compounds 3-methoxymollugin, methyl-3-prenyl-1,4-naphthoquinone-2-carboxylate, and scopoletin, while the ethyl acetate extract afforded the known 2-methoxy-3-methylanthraquinone.     

Structural criteria for depigmenting mechanism of arbutin

Arbutin, hydroquinone-O-beta-D-glucopyranoside (1) was found to inhibit the oxidation of l-tyrosine (monophenolase activity) catalyzed by mushroom tyrosinase. However, arbutin itself was oxidized as a monophenol substrate at an extremely slow rate, and this oxidation was accelerated as soon as catalytic amounts (0.01 mM) of l-3,4-dihydroxyphenylalanine (L-DOPA) became available as a cofactor. The result observed was supported by monitoring oxygen consumption. The depigmenting mechanism of arbutin previously reported is supportable if a cofactor is not available in the melanocytes. The combination with L-ascorbic acid is a useful application, particularly when oxygen is limited.     

杜仲叶黄酮类化合物的研究

目的 :从杜仲叶中分离化学成分。方法 :溶剂法和色谱法分离 ,波谱法鉴定化合物的结构。结果 :从杜仲叶中分离得到 7个化合物 ,鉴定为 5个黄酮 :山奈酚 (1)、槲皮素 (2 )、紫云英甙 (3)、陆地锦甙 (4)、芦丁 (5 ) ;1个简单的酚 :3,4 二羟基苯甲酸 (6 )和 1个葡萄糖乙甙 (7,ethylglucopyranoside)。 结论 :其中化合物 3～ 7为首次从杜仲叶中获得。     

New neolignans that inhibit DNA polymerase beta lyase

Bioassay-directed fractionation of a methyl ethyl ketone extract of the roots of Endlicheria aff. resulted in the isolation of four new neolignans (1-4) and eight known compounds, namely, canellin A (5), canellin C (6), 3'-methoxyguianin (7), (7S,8R,1'S,5'S,6'R)-Delta(2',8')-3',6'-dihydroxy-5'-methoxy-3,4-methylenedioxy-4'-oxo-8.1',7.5'-neolignan (8), armenin-B (9), dillapiole (10), 1-allyl-2,6-dimethoxy-3,4-methylenedioxybenzene (11), and omega-hydroxyisodillapiole (12). The structures of the new compounds (1-4) were established as (7S,8R,1'S,5'S,6'R)-Delta(2',8')-5',6'-dihydroxy-3'-methoxy-3,4-methylenedioxy-4'-oxo-8.1',7.5'-neolignan, (7S,8R,1'S,5'S,6'R)-Delta(2',8')-3',5',6'-trihydroxy-3,4-methylenedioxy-4'-oxo-8.1',7.5'-neolignan, 2,4-dimethoxy-5,6-methylenedioxy-1-(2-propenyl)benzene, and 2,6-dimethoxy-3,4-methylenedioxycinnamyl alcohol, respectively, on the basis of spectroscopic interpretation.     

油橄榄叶多酚类成分研究

目的研究油橄榄Olea europaea的多酚类成分。方法利用硅胶柱色谱手段,结合波谱方法分离鉴定油橄榄叶中的多酚类化合物。结果从油橄榄叶醋酸乙酯部位中分离得到15个多酚类化合物,分别鉴定为:酪醇(1)、羟基酪醇(2)、羟基酪醇乙酰酯(3)、1H-2-苯并吡喃-6,7-二醇(4)、3,4-二羟基苯甲酸(5)、3-羟基-4-甲氧基苯甲酸(6)、异鼠李素(7)、圣草酚(8)、花旗松素(9)、槲皮素(10)、木犀草素(11)、女贞苷(12)、橄榄苦苷(13)、芹菜素-7-O-葡萄糖苷(14)、木犀草素-7-O-葡萄糖苷(15)。结论化合物4～9为首次从该种植物中分离得到。     

波罗蜜叶中新的查耳酮

目的：研究波罗蜜叶的化学成分。方法：采用硅胶柱层析及Seohadex LH-20柱层析等色谱技术分离和纯化化合物，根据理化性质及近代波谱学方法鉴定结构。结果：从波罗蜜叶的乙酸乙酯部分分得8个化合物，其中5个为黄酮化合物：波罗密查耳酮ZA(artonin ZA，1)，波罗密查耳酮ZB(artonin ZB，2)，isobavachromene(3)，apigenin(4)，pinocembrin(5)，其余的为2，5-二羟基苯甲酸(6)，3，4-二羟基苯甲酸乙酯(7)，豆甾醇(8)。结论：化合物1和2为新化合物。     

猫爪草化学成分的研究(Ⅱ)

 目的研究猫爪草的化学成分。方法经柱色谱分离,理化常数和光谱分析鉴定化合物结构。结果从氯仿部分得到8个化合物,分别为邻苯二甲酸正丁酯(Ⅰ),β-单棕榈酸甘油酯(Ⅱ),β-单硬脂酸甘油酯(Ⅲ),2-氨基-3-(3,4-二羟基-苯基)-丙酸甲酯(Ⅳ),2-氨基-3-(3,4-二羟基-苯基)-丙酸乙酯(Ⅴ),5-羟甲基糠醛(Ⅵ),5-羟甲基糠酸(Ⅶ),维太菊苷(Ⅷ)。结论Ⅰ, Ⅱ,Ⅲ,Ⅵ,Ⅶ系首次从毛茛属中得到,Ⅳ,Ⅴ为提取分离过程中人工产物。