998 resultados para 5-methoxy-bufotenine


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八月瓜属植物五枫藤(Holboellia latifolia Wall.)和驳骨草属植物小驳骨(Gendarussa vulgaris Nees)均为药用植物, 前者化学成分研究不深入, 后者的化学成分未见报道。川西茶藨(Ribes takare D. Don)为茶藨子属植物, 没有化学成分的报道。本论文对三个植物的化学成分和活性成分进行了研究, 主要通过色谱方法分离得到了48 个化合物, 采用波谱分析或与已知标准品对照等手段鉴定了它们的结构, 其中有1 个新的原小檗碱类化合物和3 个新的联苯类化合物,发现了具有细胞毒活性和α-葡萄糖苷酶抑制活性的化合物。1、从五枫藤地上部分的95%乙醇提取物中分离得到了12 个化合物: 五加苷K (1)、hederagenin 3-O- α-L-rhamnopyranosyl-(1→2)- α-L-arabinopyranoside (2)、β-萘乙酸(3) 、3-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→3)]-α-L-arabinopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (4) 、3-O- α-L-rhamnopyranosyl-(1→2)-O- β- D-glucopyranosyl-(1→2)- α-L-arabinopyranosyl oleanolic acid (5) 、3-O-( β-D-glucopyranosiduronic acid)-oleanolic acid 28-O- β-D-glucopyranoside (6)、lup-20(29)-en-3-one (7)、lupeol (8)、β-谷甾醇(9)、齐墩果酸(10)、乌苏酸(11)、β-胡萝卜苷(12)。化合物1 对Lu-06、N-04 和Bre-04 癌细胞株的GI50 分别是0.77µg/mL、1.26 µg/mL 和1.55 µg/mL, 化合物2 对N-04 癌细胞株的GI50 为2.44 µg/mL。2、从小驳骨地上部分的95%乙醇提取物中分离得到了1 个原小檗碱类新化合物13-hydroxyl gusanlung A (25), β-谷甾醇(9)、齐敦果酸(10)、β-胡萝卜苷(12)、棕榈酸(1-)甘油酯(13)、棕榈酸(14)、阿苯哒唑(15)、阿苯哒唑砜(16)、阿苯哒唑亚砜(17)、aurantiamide acetate (18)、华良姜素(19)、芫花素(20)、(-)-丁香树酯醇(21)、gusanlung B (22) 、eupteleasaponinsⅤ acetate (23)、gusanlungA (24)、刺五加苷E (26)、岩白菜素(27)、咖啡酸(28)。化合物25 对肝癌细胞株(HepG2) 的GI50 为2.08 µg/mL。3、从川西茶藨地上部分的95%乙醇提取物中分离鉴定了22 个化合物: β-谷甾醇(9) 、β- 胡萝卜苷(12) 、O-acetyloleanolic aldehyde (29),4,7,8-trimethoxy-2,3-methylenedioxydibenzofuran (30) 、3', 5-dimethoxy-3, 4-methylenedioxybiphenyl (31) 、桦木醇(32) 、6,7-dimethoxy-1-methyl-3,4-dihydroquinolin-2-one (33)、3'-hydroxy-5-methoxy-3,4-methylenedioxybiphenyl (34) 、7-hydroxy-4,8-dimethoxy-2,3-methylenedioxydibenzofuran (35)、桦木醛(36)、没食子酸(37) 、6β- 羟基-4- 烯-3- 酮- 豆甾醇(38) 、5α, 8α-epidioxy-(22E,24R)-ergosta-6, 22-dien-3β-ol (39)、verrucofortine (40)、6-methoxycalpogoniumisoflavone A (41)、2-羟基二苯甲酮(42)、桦木酸(43), 3, 5-二甲氧基苯甲酸-4-O-β-D-吡喃葡萄糖苷(44)、洋芹素(45)、刺槐素(46)、水杨酸(47)、洋芹素-5-O- β-D-葡萄糖苷(48), 化合物30、31 和35 为新的联苯化合物。化合物30的α-葡萄糖苷酶抑制率为10.2% (1.00 mg/mL); 化合物35 的抑制率为17.2% (1.00mg/mL)。4、综述了1960 年以来原小檗碱类化合物药理活性研究进展。 Plants Holboellia latifolia Wall and Gendarussa vulgaris Nees, are used as folkmedicine. Ribes takare D. Don belongs to the genus Ribes. The three plants have notbeen chemically studied in detail. Chemical and bioactive study of three plants led tothe isolation of 48 compounds by chromatography. Their structures were elucidatedon the basis of spectroscopic evidence or comparison with authentic samples. Amongthe 48 componds isolated one protoberberine alkaloid and three biphenyls are newones. Cytotoxic and α-glucosidase inhibitory compounds had been found.1. Twelve compounds were isolated from the 95% ethanol extract of the aerial partof H. latifolia Wall. They were characterized as fellow: eleutheroside K (1),hederagenin-3-O- α-L-rhamnopyranosyl-(1→2)- α-L-arabinopyranoside (2),2-naphthyl acetic acid (3),3-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→3)]-α-L-arabinopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (4), 3-O- α-L-rhamnopyranosyl-(1→2)-O- β- D-glucopyranosyl-(1→2)- α-L-arabinopyranosyl oleanolic acid (5),3-O-( β-D-glucopyranosiduronic acid)-oleanolic acid-28-O- β-D-glucopyranoside (6),lup-20(29)-en-3-one (7), lupeol (8), β-sitosterol (9), oleanolic acid (10), ursolicacid (11), and β-daucosterol (12). Compound 1 showed moderate cytotoxicity againstLu-06 (GI50, 0.77 µg/mL), N-04 (GI50, 1.26 µg/mL) and Bre0-4 (GI50=1.55 µg/mL)and compound 2 showed moderate cytotoxicity against N-04 (GI50=2.44 µg/mL).2. A new protoberberine alkaloid, 13-hydroxyl gusanlung A (25), was isolated fromthe aerial part of Gendarussa vulgaris Nees, together with β-sitosterol (9), oleanolicacid (10), β-daucosterol (12), glycerol monopalmitate (13), palmific acid (14),albendazole (15), albendazole sulphone (16), albendazole sufloxide (17), aurantiamideacetate (18), kumatakenin (19), genkwanin (20), (-)-syringaresinol (21), gusanlung B(22), eupteleasaponinsⅤ acetate (23), gusanlung A (24), eleutheroside E (26),bergenin (27) and caffeic acid (28). Compound 25 showed cytotoxicity against HepG2 cells (GI50, 2.08 µg/mL).3. Phytochemical study of the Ribes takare D. Don led to the isolation of three newbiphenyls, 4,7,8-trimethoxy-2,3-methylenedioxydibenzofuran (30), 3', 5-dimethoxy-3,4-methylenedioxybiphenyl (31) and 7-hydroxy-4,8-dimethoxy-2,3-methylenedioxydibenzofuran (35), along with nineteenknown compounds, β-sitosterol (9), β-daucosterol (12), O-acetyloleanolic aldehyde(29), betulin (32), 6,7-dimethoxy-1-methyl-3,4-dihydroquinolin-2-one (33),3'-hydroxy-5-methoxy-3, 4-methylenedioxybiphenyl (34), betulinic aldehyde (36),gallic acid (37), stigmast-4-en-6β-ol-3-one (38), 5α, 8α-epidioxy-(22E, 24R)-ergosta-6,22-dien-3β-ol (39), verrucofortine (40), 6-methoxycalpogonium isoflavone A (41),2-hydroxybenzophenone (42), betulinic acid (43), 3,5-dimethoxygallic acid-4-O- β-D-glucopryranoside (44), apigenin (45), acacetin (46), salicylic acid (47) andapigenin-5-O- β-D-glucopryranoside (48). α-Glucosidase inhibitory rates ofcompound 30 and 35 were respectively 10.2% and 17.2% at a concentration of 1.00 mg/mL).4. Pharmacological activities of protoberberines were summarized.

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本学位论文报道了西藏产三种藏族传统植物药材的化学成分研究。论文由四章组成,前三章是实验部分,分别报道了尼泊尔黄堇(Corydalis hendersonii Hemsl.)、藏波罗花(Incarvillea younghusbandii Sprague)和全缘叶绿绒蒿(Meconopsis interifolia Franch.)的化学成分研究结果。从这三种青藏高原药用植物中共分离鉴定出33 个化合物,其中1 个是新化合物。第四章概述了罂粟科紫堇属植物的化学和药理研究进展。 第一章为尼泊尔黄堇的化学成分研究。通过正、反相硅胶柱色谱等分离方法从药用植物尼泊尔黄堇的地上部分共分离纯化得到12 个化合物。运用MS、1H-NMR、13C-NMR、DEPT、HMBC、NOESY 等现代波谱学方法将它们的结构鉴定为:刺罂粟碱(1) , 普托品(2) , 新那亭(3) , 斯可任(4) , tetrahydrothalifendine (5) ,9-methyl-decumbenine C (6),tetrahydroberberrubine (7),隐品碱(8),α-别隐品碱(9),6,7-methylenedioxy-1(2H)-oxoisoquinolinone (10),6-丙酮基-5,6 -二氢血根碱(11)和β-谷甾醇(12)。其中化合物6 为新化合物,为首次发现的分子骨架上C-9 位连有甲基的苯肽异喹啉类型生物碱。另外,除化合物1 和2 外,其它9 个生物碱(3~11)均为首次从该种植物中分离得到。同时,我们还对对尼泊尔黄堇中的总生物碱进行了串联质谱分析。 第二章为藏波罗花的化学成分研究。从该药用植物的地上部分共分离得到16个化合物,通过理化常数和波谱数据鉴定为:异佛手柑内酯(1),6-甲氧基当归素(2),欧前胡素(3),花椒毒内酯(4),珊瑚菜素(5),水合氧化前胡素(6),rivulobirin A (7),齐墩果酸甲酯(8),咖啡酸甲酯(9),银桦酸(10),(D)-boschniakinic acid (11),对羟基苯甲酸(12) , tert-O-β-D-glucopyranosyl-(R)-heraclenol (13) , 5-methoxy-8-O-β-D-glucopyranosyloxypsoralen (14),前胡苷V(15)和苯乙醇-O-β-D-吡喃葡萄糖-(1→2)-O-β-D-吡喃葡萄糖苷(16)。所有以上化合物均为首次从该种植物中分离得到。另外我们还首次对藏波罗花挥发油的化学成分进行了气相色谱-质谱(GC-MS)联用分析,共鉴定出39 个挥发性成分。 第三章为全缘叶绿绒蒿化学成分的分离鉴定。从传统藏药材全缘叶绿绒蒿地上部分共分离纯化出8 个化合物。通过理化常数和波谱数据将他们的结构分别鉴定为:去甲血根碱(1),β-谷甾醇(2),3-羟基-齐墩果烷-12(13)-烯-30-酸(3),6-丙酮基-5,6-二氢血根碱(4),木犀草素(5),胡萝卜苷(6),quercetin 3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (7)和普托品(8)。其中化合物1,4 和7 为首次从该种药用植物中分离得到。 第四章为综述,总结和归纳了近年来罂粟科紫堇属植物的化学和药理研究进展。 This dissertation consists of four parts. The first, second and third parts report the studies on the chemical constituents from the medicinal plants of Corydalis hendersonii, Incarvillea younghusbandii and Meconopsis interifolia. The forth part reviews the progress of the studies on Corydalis species. The first chapter is about the isolations and identifications of alkalids from the aerial parts of C. hendersonii which is a traditional Tibetan medicine to treat febrifuge, high blood pressure and hepatitis. A new isoquinoline alkaloid, 9-methyl-decumbenine C (6), together with ten known alkaloids, stylopine (1), protopine (2), canadine (3), scoulerine (4), tetrahydrothalifendine (5), tetrahydroberberrubine (7), cryptopine (8), α-allocryptopine (9), 6,7-methylenedioxy-1(2H)-isoquinolinone (10) and 6-acetonyl-5,6-dihydrosanguinarine (11), and β-sitosterol (12) were isolated. Their structures were elucidated by spectroscopic methods. Furthermore, the total alkaloids were analyzed by ESI-MSn. The second chapter is about the isolations and identifications of chemical constituents from the aerial parts of I. younghusbandii. Sixteen compounds were isolated and purified by normal and reversed phase silica gel column chromatography. By spectral analysis, there structures were identified as isobergapten (1), sphondin (2), imperatorin (3), xanthotoxin (4), phellopterin (5), heraclenol (6), rivulobirin A (7), methyl oleanolate (8), methyl caffeate (9), grevillic acid (10), (D)-boschniakinic acid (11), 4-hydroxybenzoic acid (12), tert-O-β-D-glucopyranosyl-(R)-heraclenol (13), 5-methoxy-8-O-β-D-glucopyranosyloxypsoralen (14), decuroside Ⅴ(15), and phenylethyl-O-β-Dglucopyranosyl-(1→2)-β-D-glucopyranoside (16). All of these compounds were isolated from this plant for the first time.By the way, the chemical components of the essential oil from I. younghusbandii were analyzed by GC-MS for the first time. The third chapter is about the the isolations and identifications of the chemical constituents of M. interifolia. Eight compounds were isolated and identified as norsanguinarine (1), β-sitosterol (2), 3-hydroxyolean-12(13)-en-30-oic acid (3), 6-acetonyl-5,6-dihydrosanguinarine (4), luteolin (5), daucosterol (6), quercetin 3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (7) and protopine (8). The compounds 1, 4 and 7 were isolated from this herb for the first time. The last chapter is a review of the research progress of the studies on Corydalis species, which includes the chemical constituents in this genus and their pharmacology.

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In eukaryotes, wobble uridines in the anticodons of tRNALysUUU, tRNAGluUUC and tRNAGlnUUG are modified to 5-methoxy-carbonyl-methyl-2-thio-uridine (mcm5s2U). While mutations in subunits of the Elongator complex (Elp1-Elp6), which disable mcm5 side chain formation, or removal of components of the thiolation pathway (Ncs2/Ncs6, Urm1, Uba4) are individually tolerated, the combination of both modification defects has been reported to have lethal effects on Saccharomyces cerevisiae. Contrary to such absolute requirement of mcm5s2U for viability, we demonstrate here that in the S. cerevisiae S288C-derived background, both pathways can be simultaneously inactivated, resulting in combined loss of tRNA anticodon modifications (mcm5U and s2U) without a lethal effect. However, an elp3 disruption strain displays synthetic sick interaction and synergistic temperature sensitivity when combined with either uba4 or urm1 mutations, suggesting major translational defects in the absence of mcm5s2U modifications. Consistent with this notion, we find cellular protein levels drastically decreased in an elp3uba4 double mutant and show that this effect as well as growth phenotypes can be partially rescued by excess of tRNALysUUU. These results may indicate a global translational or protein homeostasis defect in cells simultaneously lacking mcm5 and s2 wobble uridine modification that could account for growth impairment and mainly originates from tRNALysUUU hypomodification and malfunction.

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From the carbolithiation of 6-N,N-dimethylamino fulvene (3a) and different ortho-lithiated indole derivatives (5-methoxy-N-methylindole, N-methylindole and N,N-dimethylaminomethylindole), the corresponding lithium cyclopentadienide intermediate (4a-c) was formed. These three lithiated intermediates underwent a transmetallation reaction with TiCl4 resulting in dimethylamino-functionalised titanocenes (5a-c). When these titanocenes were tested against LLC-PK cells, the IC50 values obtained were of 37 and 71 mu M for titanocenes 5a and 5b respectively. The most cytotoxic titanocene in this paper, 5c showed an IC50 value of 8.4 mu M is found to be almost as cytotoxic as cis-platin, which showed an IC50 value of 3.3 mu M, when tested on the LLC-PK cell line, and titanocene 5c is approximately 250 times better than titanocene dichloride itself.

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Several noncoding microRNAs (miR or miRNA) have been shown to regulate the expression of drug-metabolizing enzymes and transporters. Xenobiotic drug-induced changes in enzyme and transporter expression may be associated with the alteration of miRNA expression. Therefore, this study investigated the impact of 19 xenobiotic drugs (e. g. dexamethasone, vinblastine, bilobalide and cocaine) on the expression of ten miRNAs (miR-18a, -27a, -27b, -124a, -148a, -324-3p, -328, -451, -519c and -1291) in MCF-7, Caco-2, SH-SY5Y and BE(2)-M17 cell systems. The data revealed that miRNAs were differentially expressed in human cell lines and the change in miRNA expression was dependent on the drug, as well as the type of cells investigated. Notably, treatment with bilobalide led to a 10-fold increase of miR-27a and a 2-fold decrease of miR-148a in Caco-2 cells, but no change of miR-27a and a 2-fold increase of miR-148a in MCF-7 cells. Neuronal miR-124a was generally down-regulated by psychoactive drugs (e. g. cocaine, methadone and fluoxetine) in BE(2)-M17 and SH-SY5Y cells. Dexamethasone and vinblastine, inducers of drug-metabolizing enzymes and transporters, suppressed the expression of miR-27b, -148a and -451 that down-regulate the enzymes and transporters. These findings should provide increased understanding of the altered gene expression underlying drug disposition, multidrug resistance, drug-drug interactions and neuroplasticity. Copyright (C) 2011 John Wiley & Sons, Ltd.

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Hypochlorous acid (HOCl) released by activated leukocytes has been implicated in the tissue damage that characterizes chronic inflammatory diseases. In this investigation, 14 indole derivatives, including metabolites such as melatonin, tryptophan and indole-3-acetic acid, were screened for their ability to inhibit the generation of this endogenous oxidant by stimulated leukocytes. The release of HOCl was measured by the production of taurine-chloramine when the leukocytes (2 x 10(6) cells/mL) were incubated at 37ºC in 10 mM phosphate-buffered saline, pH 7.4, for 30 min with 5 mM taurine and stimulated with 100 nM phorbol-12-myristate acetate. Irrespective of the group substituted in the indole ring, all the compounds tested including indole, 2-methylindole, 3-methylindole, 2,3-dimethylindole, 2,5-dimethylindole, 2-phenylindole, 5-methoxyindole, 6-methoxyindole, 5-methoxy-2-methylindole, melatonin, tryptophan, indole-3-acetic acid, 5-methoxy-2-methyl-3-indole-acetic acid, and indomethacin (10 µM) inhibited the chlorinating activity of myeloperoxidase (MPO) in the 23-72% range. The compounds 3-methylindole and indole-3-acetic acid were chosen as representative of indole derivatives in a dose-response study using purified MPO. The IC50 obtained were 0.10 ± 0.03 and 5.0 ± 1.0 µM (N = 13), respectively. These compounds did not affect the peroxidation activity of MPO or the production of superoxide anion by stimulated leukocytes. By following the spectral change of MPO during the enzyme turnover, the inhibition of HOCl production can be explained on the basis of the accumulation of the redox form compound-II (MPO-II), which is an inactive chlorinating species. These results show that indole derivatives are effective and selective inhibitors of MPO-chlorinating activity.

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An isolate of Curvularia sp. was obtained from the leaves of Ocotea corymbosa, a native plant of the Brazilian Cerrado. The ethyl acetate extract from culture of this fungus afforded two benzopyran derivatives: (2′S)-2-(propan-2′-ol)-5-hydroxy-benzopyran-4-one (2) and 2,3-dihydro-2-methyl-benzopyran-4,5-diol (4); and two known benzopyrans: 2-methyl-5-methoxy-benzopyran-4-one (1) and (2R)-2,3-dihydro-2-methyl-5-methoxy- benzopyran-4-one (3). The structures of 2 and 4 were established on the basis of comprehensive spectroscopic analysis, mainly using 1D and 2D NMR experiments. The benzopyrans 1 and 2 showed weak in vitro antifungal activity against Cladosporium sphaerospermum and C. cladosporioides. Analyses of the biological activities were also carried out on HeLa (human cervix tumor) and CHO (Chinese hamster ovary) cells, aiming to evaluate their potential effects on mammalian cell line proliferation. Results from both cell lines indicated that compound 2 was able to induce cell proliferation: 70% on HeLa cells and 25% on CHO cells. © 2005 Elsevier Ltd. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Background Helichrysum species are used extensively for stress-related ailments and as dressings for wounds normally encountered in circumcision rites, bruises, cuts and sores. It has been reported that Helichysum species are used to relief abdominal pain, heart burn, cough, cold, wounds, female sterility, menstrual pain. Results From the extracts of Helichrysum foetidum (L.) Moench, six known compounds were isolated and identified. They were 7, 4′-dihydroxy-5-methoxy-flavanone (1), 6′-methoxy-2′,4, 4′-trihydroxychalcone (2), 6′-methoxy-2′,4-dihydroxychalcone -4′-O-β-D-glucoside (3), apigenin (4), apigenin-7-O-β-D-glucoside (5), kaur-16-en-18-oic acid (6) while two known compounds 3,5,7-trihydroxy-8-methoxyflavone (12), 4,5-dicaffeoyl quinic acid (13) together with a mixture of phytosterol were isolated from the methanol extract of Helichrysum mechowianum Klatt. All the compounds were characterized by spectroscopic and mass spectrometric methods, and by comparison with literature data. Both extracts and all the isolates were screened for the protease inhibition, antibacterial and antifungal activities. In addition, the phytochemical profiles of both species were investigated by ESI-MS experiments. Conclusions These results showed that the protease inhibition assay of H. foetidum could be mainly attributed to the constituents of flavonoids glycosides (3, 5) while the compound (13) from H. mechowianum contributes to the stomach protecting effects. In addition, among the antibacterial and antifungal activities of all the isolates, compound (6) was found to possess a potent inhibitor effect against the tested microorganisms. The heterogeneity of the genus is also reflected in its phytochemical diversity. The differential bioactivities and determined constituents support the traditional use of the species. Molecular modelling was carried out by computing selected descriptors related to drug absorption, distribution, metabolism, excretion and toxicity (ADMET).

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The trunk wood of an Amazonian Aniba species contains three novel neolignans: (2R, 3R, 3aS, 5R)-3a-allyl-5-methoxy-2-(3,4,5-trimethoxyphenyl)-3-methyl-2,3,3a,4,5,6-hexahydro-6-oxobenzofuran (canellin-D), (2R,3R,3aS,5R)-3a-allyl-5,7-dimethoxy-2-(3-methoxy-4,5-methylenedioxyphenyl)-3-methyl-2,3,3a,4,5,6-hexahydro-6-oxobenzofuran (canellin-E) and (2S,3S,3aS,5R)-3a-allyl-5-methoxy-2-(3-methoxy-4,5-methylenedioxyphenyl)-3-methyl-2,3,3a,4,5,6-hexahydro-6-oxobenzofuran (armenin-C). The absolute stereochemistries of these and of all other known hexahydro-6-oxobenzofurans were determined by CD comparisons with model compounds. © 1984.

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Phytochemical studies of Hortia brasiliana and Hortia oreadica (Rutaceae) have led to the identification of three novel dihydrocinnamic acids: 5-methoxy-2,2-dimethyl-2H-1-benzopyran-8-propanoic acid, 5,6-dimethoxy-2,2-dimethyl-2H-1-benzopyran-8-propanoic acid and erythro-2-hydroxy-4-methoxy-3-(1,2,3-trihydroxy-3-methylbutyl) benzenepropanoic acid from H. brasiliana and the second compound and six known dihydrocinnamic acids from H. oreadica. Engler included Hortia as the single Neotropical genus in the Toddalioideae subtribe Toddaliinae. However, the range of dihydrocinnamic acid derivatives found in H. brasiliana and H. oreadica show that they contain similar compounds to other species of Hortia and clearly point to their phytochemical affinities with other Rutoideae species. (C) 2012 Elsevier Ltd. All rights reserved.

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Exogenous melatonin is widely used for sleep disorders and has potential value in neuroprotection, cardioprotection and as an antioxidant. Here, a novel method is described for the determination of melatonin and six metabolites in mouse urine by use of LC-MS/MS and GC-MS. LC-MS/MS is used for the measurement of melatonin, N1-acetyl-5-methoxykynuramine (AMK), N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) and 6-hydroxymelatonin (6-HMEL), while GC/MS is used for the determination of N-[2-(5-methoxy-2-oxo-2,3-dihydro-1H-indol-3-yl)-ethyl]-acetamide (2-OMEL) and cyclic 3-hydroxymelatonin (3-HMEL) with detection limits on column of 0.02-0.5 pmol, depending on the metabolite. Following oral administration of melatonin to mice, a 0-24 hr urine collection revealed the presence of melatonin (0.2% dose), 6-HMEL (37.1%) and NAS (3.1%) comprising >90% of the total metabolites; AMK and AFMK were also detected at 0.01% each; 2-OMEL was found at 2.2% of the dose, which is >100 times more than the AMK/AFMK pathway, and comprises >5% of the melatonin-related material detected in mouse urine. 3-HMEL was largely found as a sulfate conjugate. These studies establish sensitive assays for determination of six melatonin metabolites in mouse urine and confirm the potential for antioxidant activity of melatonin through the identification in vivo of AMK and AFMK, ring-opened metabolites with a high capacity for scavenging reactive oxygen species.

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A molecular, porous crystalline material constructed from neutral helical coordination polymers incorporating manganese(II) ions and two types of bridging ligands, namely the deprotonated form of 2-hydroxy-5-methoxy-3-nitrobenzaldehyde (HL) and isobutyrate (iB−), has been obtained and structurally characterized. Structural analysis reveals that within the coordination polymer each benzaldehyde derivative ligates two manganese ions in 6-membered chelating rings, and the isobutyrate ligands cooperatively chelate either two or three manganese ions. The solid state assembly of the resulting polymeric chains of formula [Mn4(L)2(iB)6]n (1), described in the polar space group R3c, is associated with tubular channels occupied by MeCN solvent molecules (1·xMeCN; x ≤ 9). TGA profiles and PXRD measurements demonstrate that the crystallinity of the solid remains intact in its fully desolvated form, and its stability and crystallinity are ensured up to a temperature of 190 °C. Gas adsorption properties of desolvated crystals were probed, but no remarkable sorption capacity of N2 and only a limited one for CO2 could be observed. Magnetic susceptibility data reveal an antiferromagnetic type of coupling between adjacent manganese(II) ions along the helical chains with energy parameters J1 = −5.9(6) cm−1 and J2 = −1.8(9) cm−1.