Regio- and stereospecific oxidation of 9,10-dihydroanthracene and 9,10-dihydrophenanthrene by naphthalene dioxygenase: structure and absolute stereochemistry of metabolites.

The oxidation of 9,10-dihydroanthracene and 9,10-dihydrophenanthrene was examined with mutant and recombinant strains expressing naphthalene dioxygenase from Pseudomonas putida (NCIB 9816.4. Salicylate-induced cells of P. putida strain 9816/11 and isopropylthiogalactopyranoside-induced cells of Escherichia coli JM109(DE3)(pDTG141) oxidized 9,10-dihydroanthracene to (+)-cis-1R,2S)-1,2-dihydroxy-1,2,9,10-tetrahydroanthracene (> 95% relative yield; > 95% enantiomeric excess) as the major product. 9-Hydroxy-9,10-dihydroanthracene (< 5% relative yield) was a minor product formed by both organisms. The same cells oxidized 9,10-dihydrophenanthrene to (+)-cis-(3S,4R)-3,4-dihydroxy-3,4,9,10-tetrahydrophenanthrene (70% relative yield; > 95% enantiomeric excess) and (+)-(S)-9-hydroxy-9,10-dihydrophenanthrene (30% relative yield). The major reaction catalyzed by naphthalene dioxygenase with 9,10-dihydroanthracene and 9,10-dihydrophenanthrene was stereospecific dihydroxylation in which both of the previously undescribed cis-diene diols were of R configuration at the benzylic center adjacent to the bridgehead carbon atom. The results suggest that for benzocylic substrates, the location of benzylic carbons influences the type of reaction(s) catalyzed by naphthalene dioxygenase.     

华石斛化学成分研究

为了解华石斛(Dendrobium sinense)的化学成分,采用多种柱色谱技术从其全草乙醇提取液中分离纯化了10个化合物,经波谱分析分别鉴定为:鼓槌石斛素(1)、2′,4′-二羟基查尔酮(2)、2,5,7-三羟基-4-甲氧基-9,10-二氢菲(3)、4,7-二羟基-2,3-二甲氧基-9,10-二氢菲(4)、2,5-二羟基-3,4-二甲氧基-9,10-二氢菲(5)、2,7-二羟基-3,4,6-三甲氧基-9,10-二氢菲(6)、(E)松柏醛(7)、反式对羟基肉桂酸酯(8)、对羟基苯丙酸甲酯(9)和十二元内环酯(10)。所有化合物均为首次从华石斛中分离得到,其中化合物2、6、7和10对乙酰胆碱酯酶具有一定的抑制活性。     

Phenanthrenes and a dihydrophenanthrene from Tamus communis and their cytotoxic activity

From the petroleum ether extract of the rhizomes of Tamus communis, the 7-hydroxy-2,3,4,8-tetramethoxyphenanthrene (1) was isolated, together with the known 2,3,4-trimethoxy-7,8-methylenedioxyphenanthrene (2), 3-hydroxy-2,4,-dimethoxy-7,8-methylenedioxyphenanthrene (3), 2-hydroxy-3,5,7-trimethoxyphenanthrene (4) and 2-hydroxy-3,5,7-trimethoxy-9,10-dihydrophenanthrene (5), through cytotoxic assay guidance. The structures were determined by means of HREIMS, (1)H NMR, JMOD and NOESY experiments. The cytotoxic effects of the isolated compounds were tested on cervix adenocarcinoma (HeLa) cells, with the MTT assay. The results demonstrated that, with the exception of 2, all these compounds displayed pronounced cytotoxic activity; especially 1 and 3 exhibited significant cell growth inhibitory effects, with IC(50)=8.52+/-0.70 and 3.64+/-0.12 microM, respectively.     

Phenanthrenes from Dendrobium plicatile

From Dendrobium plicatile stems, three phenanthrenes were isolated. The structures are 2,5-dihydroxy-4,9,10-trimethoxyphenanthrene, 2,5-dihydroxy-4-methoxyphenanthrene and 2,5,9-trihydroxy-4-methoxy-9,10-dihydrophenanthrene.     

Degradation of phenanthrene and anthracene by cell suspensions of Mycobacterium sp. strain PYR-1

Cultures of Mycobacterium sp. strain PYR-1 were dosed with anthracene or phenanthrene and after 14 days of incubation had degraded 92 and 90% of the added anthracene and phenanthrene, respectively. The metabolites were extracted and identified by UV-visible light absorption, high-pressure liquid chromatography retention times, mass spectrometry, (1)H and (13)C nuclear magnetic resonance spectrometry, and comparison to authentic compounds and literature data. Neutral-pH ethyl acetate extracts from anthracene-incubated cells showed four metabolites, identified as cis-1,2-dihydroxy-1,2-dihydroanthracene, 6,7-benzocoumarin, 1-methoxy-2-hydroxyanthracene, and 9,10-anthraquinone. A novel anthracene ring fission product was isolated from acidified culture media and was identified as 3-(2-carboxyvinyl)naphthalene-2-carboxylic acid. 6,7-Benzocoumarin was also found in that extract. When Mycobacterium sp. strain PYR-1 was grown in the presence of phenanthrene, three neutral metabolites were identified as cis- and trans-9,10-dihydroxy-9,10-dihydrophenanthrene and cis-3,4-dihydroxy-3,4-dihydrophenanthrene. Phenanthrene ring fission products, isolated from acid extracts, were identified as 2,2'-diphenic acid, 1-hydroxynaphthoic acid, and phthalic acid. The data point to the existence, next to already known routes for both gram-negative and gram-positive bacteria, of alternative pathways that might be due to the presence of different dioxygenases or to a relaxed specificity of the same dioxygenase for initial attack on polycyclic aromatic hydrocarbons.     

Phenanthrenoids from the wetland Juncus acutus

Nine 9,10-dihydrophenanthrenes, three phenanthrenes and a related pyrene have been isolated from the wetland plant Juncus acutus. The structures have been attributed by means of their spectral data and chemical correlation. 5-(1-Ethoxy-ethyl)-2-hydroxy-7-methoxy-1,8-dimethyl-9,10-dihydrophenanthrene and 5-(1-phytoxy-ethyl)-2-hydroxy-7-methoxy-1,8-dimethyl-9,10-dihydrophenanthrene, 2,7-dihydroxy-1-methyl-5-vinylphenanthrene, 2,7-dimethoxy-1,6-dimethyl-5-vinylphenanthrene and 2,7-dihydroxy-1,6-dimethylpyrene are described for the first time. Many of the compounds showed in vitro phytotoxicity against Selenastrum capricornutum, a microalga used in aquatic tests.     

Methylphenanthrenes from Sagotia racemosa

The trunk wood of Sagotia racemosa Baill. (Euphorbiaceae) contains two previously unknown micrandrols E (6-hydroxy-7-methoxy-1,2-dimethylphenanthrene) and F (6-hydroxy-7-methoxy-1,2-dimethyl-9,10-dihydrophenanthrene).     

Stereoselective metabolism of anthracene and phenanthrene by the fungus Cunninghamella elegans.

The fungus Cunninghamella elegans oxidized anthracene and phenanthrene to form predominately trans-dihydrodiols. The metabolites were isolated by reversed-phase high-pressure liquid chromatography for structural and conformational analyses. Comparison of the circular dichroism spectrum of the fungal trans-1,2-dihydroxy-1,2-dihydroanthracene to that formed by rat liver microsomes indicated that the major enantiomer of the trans-1,2-dihydroxy-1,2-dihydroanthracene formed by C. elegans had an S,S absolute stereochemistry, which is opposite to the predominately 1R,2R dihydrodiol formed by rat liver microsomes. C. elegans oxidized phenanthrene primarily in the 1,2-positions to form trans-1,2-dihydroxy-1,2-dihydrophenanthrene. In addition, a minor amount of trans-3,4-dihydroxy-3,4-dihydrophenanthrene was detected. Metabolism at the K-region (9,10-positions) of phenanthrene was not detected. Comparison of the circular dichroism spectra of the phenanthrene trans-1,2- and trans-3,4-dihydrodiols formed by C. elegans to those formed by mammalian enzymes indicated that each of the dihydrodiols formed by C. elegans had an S,S absolute configuration. The results indicate that there are differences in both the regio- and stereoselective metabolism of anthracene and phenanthrene between the fungus C. elegans and rat liver microsomes.     

盘龙参中的两个新二氢菲类

采用硅胶和凝胶柱色谱,以及制备性薄层色谱等多种分离手段,从盘龙参全草中分离得到了2个新的9,10-二氢菲类化合物,运用NMR和MS等波谱技术分别鉴定为4-羟基-2-甲氧基-8-呋喃[4′,5′:7,8]-9,10-二氢菲(1),4-羟基-2-甲氧基-8-{2',2'-二甲基吡喃[5',6':7,8]}-9,10-二氢菲(2).     

Degradation of Phenanthrene and Anthracene by Cell Suspensions of Mycobacterium sp. Strain PYR-1

Cultures of Mycobacterium sp. strain PYR-1 were dosed with anthracene or phenanthrene and after 14 days of incubation had degraded 92 and 90% of the added anthracene and phenanthrene, respectively. The metabolites were extracted and identified by UV-visible light absorption, high-pressure liquid chromatography retention times, mass spectrometry, ¹H and ¹³C nuclear magnetic resonance spectrometry, and comparison to authentic compounds and literature data. Neutral-pH ethyl acetate extracts from anthracene-incubated cells showed four metabolites, identified as cis-1,2-dihydroxy-1,2-dihydroanthracene, 6,7-benzocoumarin, 1-methoxy-2-hydroxyanthracene, and 9,10-anthraquinone. A novel anthracene ring fission product was isolated from acidified culture media and was identified as 3-(2-carboxyvinyl)naphthalene-2-carboxylic acid. 6,7-Benzocoumarin was also found in that extract. When Mycobacterium sp. strain PYR-1 was grown in the presence of phenanthrene, three neutral metabolites were identified as cis- and trans-9,10-dihydroxy-9,10-dihydrophenanthrene and cis-3,4-dihydroxy-3,4-dihydrophenanthrene. Phenanthrene ring fission products, isolated from acid extracts, were identified as 2,2′-diphenic acid, 1-hydroxynaphthoic acid, and phthalic acid. The data point to the existence, next to already known routes for both gram-negative and gram-positive bacteria, of alternative pathways that might be due to the presence of different dioxygenases or to a relaxed specificity of the same dioxygenase for initial attack on polycyclic aromatic hydrocarbons.     

Antimitotic activity and reversal of breast cancer resistance protein-mediated drug resistance by stilbenoids from Bletilla striata

Eight stilbenoids, 1-(p-hydroxybenzyl)-4,8-dimethoxyphenanthrene-2,7-diol (1), 2,7-dihydroxy-1,3-bis(p-hydroxybenzyl)-4-methoxy-9,10-dihydrophenanthrene (2), 4,7-dihydroxy-1-(p-hydroxybenzyl)-2-methoxy-9,10-dihydrophenanthrene (3), 3,3'-dihydroxy-2',6'-bis(p-hydroxybenzyl)-5-methoxybibenzyl (4), 3',5-dihydroxy-2-(p-hydroxybenzyl)-3-methoxybibenzyl (5), blestriarenes B (6) and C (7), and blestrianol A (8) have been isolated by the guidance of inhibitory effect of tubulin polymerization from the tubers of Bletilla striata (Orchidaceae). Among them, both of bisbenzyls 4 and 5 inhibited the polymerization of tubulin at IC(50) 10muM, respectively. Furthermore bisbenzyl 4 potentiated the cytotoxicity of SN-38 in BCRP-transduced K562 (K562/BCRP) cells.     

Structure and antifungal activity of hircinol,loroglossol and orchinol

The structure of hircinol, a phytoalexin isolated from Loroglossum hircinum has been established as 2, 5-dihydroxy-4-methoxy-9,10-dihydrophenanthrene. This phytoalexin, the second to be identified in the Orchidaceae, is less effective than orchinol, and its isomeric co-metabolite, loroglossol, 5-hydroxy-2,4-dimethyoxy-9,10-dihydrophenanthrene, is inactive.     

Metabolism of phenanthrene by the marine cyanobacterium Agmenellum quadruplicatum PR-6.

Under photoautotrophic growth conditions, the marine cyanobacterium Agmenellum quadruplicatum PR-6 metabolized phenanthrene to form trans-9,10-dihydroxy-9,10-dihydrophenanthrene (phenanthrene trans-9,10-dihydrodiol) and 1-methoxyphenanthrene as the major ethyl acetate-extractable metabolites. Small amounts of phenanthrols were also formed. The metabolites were purified by high-pressure liquid chromatography and identified from their UV, infrared, mass, and proton magnetic resonance spectral properties. A. quadruplicatum PR-6 formed phenanthrene trans-9,10-dihydrodiol with a 22% enantiomeric excess of the (-)-9S,10S-enantiomer. Incorporation experiments with 18O2 showed that one atom of oxygen from O2 was incorporated into the dihydrodiol. Toxicity studies, using an algal lawn bioassay, indicated that 9-phenanthrol and 9,10-phenanthrenequinone inhibit the growth of A. quadruplicatum PR-6.     

Metabolism of phenanthrene by the marine cyanobacterium Agmenellum quadruplicatum PR-6.

Under photoautotrophic growth conditions, the marine cyanobacterium Agmenellum quadruplicatum PR-6 metabolized phenanthrene to form trans-9,10-dihydroxy-9,10-dihydrophenanthrene (phenanthrene trans-9,10-dihydrodiol) and 1-methoxyphenanthrene as the major ethyl acetate-extractable metabolites. Small amounts of phenanthrols were also formed. The metabolites were purified by high-pressure liquid chromatography and identified from their UV, infrared, mass, and proton magnetic resonance spectral properties. A. quadruplicatum PR-6 formed phenanthrene trans-9,10-dihydrodiol with a 22% enantiomeric excess of the (-)-9S,10S-enantiomer. Incorporation experiments with 18O2 showed that one atom of oxygen from O2 was incorporated into the dihydrodiol. Toxicity studies, using an algal lawn bioassay, indicated that 9-phenanthrol and 9,10-phenanthrenequinone inhibit the growth of A. quadruplicatum PR-6.     

淫羊藿中的新黄酮甙

淫羊藿甙(icariin,1)和1个新的黄酮甙类成分-新淫羊藿甙(neoicariin,2)已从中药淫羊藿(Epimedium sagittatum)的地上部分分到,新淫羊藿甙(2)的化学结构经光谱分析并通过^1H-^1H COSY,^1H-^1H NOE,HMQC,HMBC等二维核磁共振谱和化学方法鉴定为3,5,7-三羟基-4’-甲氧基-8-(2”,3”-环氧)异戊基黄酮-3-O-α-L-鼠李吡喃糖甙。     

海南石斛化学成分研究

为了解海南石斛(Dendrobium hainanense Rolfe)的化学成分,采用色谱技术从海南石斛茎叶中分离得到14个化合物,经波谱分析分别鉴定为:2,6-二甲氧基对苯醌(1)、(+)-dehydrovomifoliol(2)、blumenol A(3)、2,7-二羟基-3,4-二甲氧基-9,10-二氢菲(4)、2,7-二羟基-3,4-二甲氧基菲(5)、3,7-二羟基-2,4-二甲氧基菲(6)、3-羟基-2,4,7-三甲氧基-9,10-二氢菲(7)、3-羟基-2,4,7-三甲氧基菲(8)、3,4,7-三羟基-2-甲氧基菲(9)、3,7-二羟基-2,4-二甲氧基-9,10-二氢菲(10)、(+)-lyoniresinol(11)、丁香脂素(12)、denchrysan A(13)和nobilone(14)。这些化合物均为首次从海南石斛中分离得到。活性测试结果表明化合物4~6、8~9、11和14对乙酰胆碱酯酶有抑制活性。     

Syntheses and evaluation of multicaulin and miltirone-like compounds as antituberculosis agents

Four multicaulin and miltirone-like phenanthrene derivatives were synthesised and evaluated as antituberculosis agents. The crucial step of the synthesis was Pschorr coupling of 4-(3-isopropyl-4-methoxyphenyl)-2-(2-aminophenyl)ethane (13) to give 2-isopropyl-3-methoxy-9,10-dihydrophenanthrene (9) and 4-isopropyl-3-methoxy-9,10-dihydrophenanthrene (9a). Compound 9 was converted to multicaulin and miltirone-like phenanthrene derivatives by further reactions. The best antituberculosis activity was exhibited by 2-isopropylphenanthrene-3-ol (11).     

藏药翁布的黄酮类化学成分研究

从藏药翁布(Myricaria germanica)的60%丙酮提取物中分离得到了11个黄酮类化合物,利用光谱、波谱分析法鉴定其结构分别为:35,,4’-三羟基-73,’-二甲氧基黄酮(1),3,5,4’-三羟基-7-甲氧基黄酮(2),3,5,3’,4’-四羟基-7-甲氧基黄酮(3),35,7,-三羟基-4’-甲氧基黄酮(4),柽柳素(5),山柰酚(6),槲皮素-3-O-β-D-葡萄糖苷(7)5,,7,4’-三羟基-3-O-β-D-葡萄糖醛酸(8),5,7,3’4,’-四羟基-3-O-β-D-葡萄糖醛酸(9),槲皮苷(10)和阿福豆苷(11)。上述化合物均为首次从该植物中分离得到,其中化合物4、5、7～11为首次从水柏枝属植物中分离得到。     

Repair of DNA damaged by mutagenic metabolites of benzo(a)pyrene in human cells

The repair of human DNA after damage by known and potential metabolites of benzo(a)pyrene has been examined utilizing the bromodeoxyuridine photolysis assay. Repair was characterized as either ultraviolet (“long”) or ionizing radiation type (“short”) repair utilizing normal cells and cells deficient in ultraviolet-type repair endonuclease from a patient with xeroderma pigmentosum (XP). We have found that only (±)-7β,8-dihydroxy-9β,-10β-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BP diol epoxide 1) and its disastereomer, (±)-7β,8,-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BP diol epoxide 2) elicit damage to DNA which is recognizable by the ultraviolet excision repair system in normal human cells. Benzo(a)pyrene 4,5-, 9,10-, 11,12-oxides do not elicit damage which is repairable by this repair system. The 1,2-diol-3,4-epoxides from naphthalene have no measurable activity in our assay. These results indicate that both the benzo(a)pyrene ring structure and the diol epoxide groups are important in causing the damage to DNA which is repairable by the ultraviolet excision repair system. These results parallel the reported high mutagenic activity of these compounds and support the concept that benzo(a)pyrene 7,8-diol-9,10-epoxides may be the ultimate, metabolically activated forms of benzo(a)pyrene.     

Xanthones with quinone reductase-inducing activity from the fruits of Garcinia mangostana (Mangosteen)

Bioactivity-guided fractionation of a dichloromethane-soluble extract of Garcinia mangostana fruits has led to the isolation and identification of five compounds, including two xanthones, 1,2-dihydro-1,8,10-trihydroxy-2-(2-hydroxypropan-2-yl)-9-(3-methylbut-2-enyl)furo[3,2-a]xanthen-11-one (1) and 6-deoxy-7-demethylmangostanin (2), along with three known compounds, 1,3,7-trihydroxy-2,8-di-(3-methylbut-2-enyl)xanthone (3), mangostanin (4), and alpha-mangostin (5). The structures of compounds 1 and 2 were determined from analysis of their spectroscopic data. All isolated compounds in the present study together with eleven other compounds previously isolated from the pericarp of mangosteen, were tested in an in vitro quinone reductase-induction assay using murine hepatoma cells (Hepa 1c1c7) and an in vitro hydroxyl radical antioxidant assay. Of these, compounds 1-4 induced quinone reductase (concentration to double enzyme induction, 0.68-2.2microg/mL) in Hepa 1c1c7 cells and gamma-mangostin (6) exhibited hydroxyl radical-scavenging activity (IC50, 0.20microg/mL).