Synthesis and antiviral activity of certain 4-substituted and 2,4-disubstituted 7-[(2-hydroxyethoxy)methyl]pyrrolo[2,3-d]pyrimidines

Treatment of the sodium salt of 4-chloro-2-(methylthio)pyrrolo[2,3-d]pyrimidine (2) with (2-acetoxyethoxy)methyl bromide (3) has provided 4-chloro-2-(methylthio)-7[(2-acetoxyethoxy)methyl]pyrrolo[2,3- d]pyrimidine (4). Ammonolysis of 4 at room temperature gave 4-chloro-2-(methylthio)-7-[(2-hydroxyethoxy)methyl]pyrrolo[2,3- d]pyrimidine (5). However, ammonolysis of 5 at 130 degrees C furnished 4-amino-2-(methylthio)-7-[(2-hydroxyethoxy)methyl]-pyrrolo[2,3- d]pyrimidine (6), which on desulfurization with Raney Ni yielded 4-amino-7-[(2-hydroxyethoxy)-methyl]pyrrolo[2,3-d]pyrimidine (7) (acyclic analogue of tubercidin). The oxidation of 6 with m-chloroperbenzoic acid provided the sulfone derivative 8. A nucleophilic displacement of the 2-methylsulfonyl group from 8 with methoxide anion provided 4-amino-2-methoxy-7-[(2-hydroxyethoxy)methyl]pyrrolo[2,3-d]pyrimidine (9). Demethylation of 9 with iodotrimethylsilane gave 4-amino-2-hydroxy-7-[(2-hydroxyethoxy)methyl]pyrrolo[2,3-d]pyrimidine (10). Treatment of 2,4-dichloropyrrolo[2,3-d]pyrimidine (11) with 3 gave the protected acyclic compound 12, which on deacetylation and ammonolysis under controlled reaction conditions gave 2,4-dichloro-7-[(2-hydroxyethoxy)-methyl]pyrrolo[2,3-d]pyrimidine (13) and 4-amino-2-chloro-7-[(2-hydroxyethoxy)methyl]pyrrolo[2,3- d]pyrimidine (14), respectively. The condensation of 2-acetamido-4-chloropyrrolo[2,3-d]pyrimidine (15) with 3 gave the protected acyclic compound 16, which on concomitant deacetylation and ammonolysis with methanolic ammonia at an elevated temperature yielded 2,4-diamino-7-[(2-hydroxyethoxy)methyl]pyrrolo[2,3-d]pyrimidine (17) in moderate yield. In tests involving human cytomegalovirus (HCMV) and herpes simplex virus type 1 (HSV-1), only slight activity and cytotoxicity were observed. The most active compounds (12 and 13) were slightly more active against HCMV than acyclovir, but both compounds were inactive against HSV-1. The activity against HCMV, however, was not well separated from cytotoxicity leading to the conclusion that these compounds did not merit further study.     

Macromolecular prodrugs. IX. Synthesis of polymer-fenoprofen conjugates

Synthesis of several polymer-fenoprofen conjugates is described. Fenoprofen was first chemically modified into benzotriazolide 2 and amino acid amide derivatives: glycine fenoprofenamide (3a) and beta-alanine fenoprofenamide (3b) and their benzotriazolides 6a and 6b. Compounds 2 and 6 readily reacted with polyhydroxy aspartamide-type polymers, i.e. poly[alpha,beta-(N-2-hydroxyethyl-DL-aspartamide)] (PHEA) and poly[alpha,beta-(N-3-hydroxypropyl-DL-aspartamide)] (PHPA) forming conjugates 5, 8a,b and 9a,b, respectively. Conjugate 11 was obtained by partial aminolysis of poly-DL-(2,5-dioxo-1,3-pyrrolidinediyl) (PSI) with 2-aminoethyl fenoprofenamide (3c), followed by total aminolysis with 2-hydroxyethylamine. The synthesised polymer-drug conjugates differed in type of covalent bounding, type and/or length of spacer and drug-loading.     

群海绵Agelas sp.的化学成分研究

目的 研究海绵Agelas sp.的化学成分。方法 运用乙醇提取、硅胶、Sephadex-LH₂₀色谱柱、HPLC等多种方法进行分离和纯化,根据理化性质和波谱数据进行结构鉴定。结果 分离得到9个化合物,经结构鉴定分别为4,5-二溴吡咯-2-甲酰胺（1）、4,5-二溴吡咯-2-甲酸（2）、4,5-二溴吡咯-2-甲酸甲酯（3）、N-（4,5-二溴-2-吡咯甲酰基）甘氨酸甲酯（4）、1-（4,5-二溴-2-吡咯甲酰胺基）丙酸甲酯（5）、1-（4,5-二溴-2-吡咯甲酰胺基）丙酸乙酯（6）、异吲哚-1,3-二酮（7）、2（3H）-苯并噻唑酮（8）和manzacidin C（9）。结论 化合物4~9为首次从该属海绵中分离得到,其中化合物4~6为新天然产物。     

Synthesis and biological activity of 6-azacadeguomycin and certain 3,4,6-trisubstituted pyrazolo[3,4-d]pyrimidine ribonucleosides

Several 3,4,6-trisubstituted pyrazolo[3,4-d]pyrimidine ribonucleosides were prepared and tested for their biological activity. High-temperature glycosylation of 3,6-dibromoallopurinol with 1-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose in the presence of BF3 X OEt2, followed by ammonolysis, provided 6-amino-3-bromo-1-beta-D-ribofuranosylpyrazolo-[3,4-d]pyrimidin-4(5H)-on e. Similar glycosylation of either 3-bromo-4(5H)-oxopyrazolo [3,4-d]pyrimidin-6-yl methyl sulfoxide or 6-amino-3-bromopyrazolo [3,4-d]pyrimidin-4(5H)-one, and subsequent ammonolysis, also gave 7a. The structural assignment of 7a was on the basis of spectral studies, as well as its conversion to the reported guanosine analogue 1d. Application of this glycosylation procedure to 6-(methylthio)-4(5H)-oxopyrazolo[3,4-d]pyrimidine-3-carboxamide gave the corresponding N-1 glycosyl derivative. Dethiation and debenzoylation of 16a provided an alternate route to the recently reported 3-carbamoylallopurinol ribonucleoside thus confirming the structural assignment of 16a and the nucleosides derived therefrom. Oxidation of 16a and subsequent ammonolysis afforded 6-amino-1-beta-D-ribofuranosyl-4(5H)-oxopyrazolo[3, 4-d]pyrimidine-3-carboxamide. Alkaline treatment of 15a gave 6-azacadeguomycin. Acetylation of 15a, followed by dehydration with phosgene, provided the versatile intermediate 6-amino-1-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)-4(5H)-oxopyrazolo [3, 4-d]pyrimidine-3-carbonitrile. Deacetylation of 19 gave 6-amino-1-beta-D-ribofuranosyl-4(5H)-oxopyrazolo[3, 4-d]pyrimidine-3-carbonitrile. Reaction of 19 with H2S gave 6-amino-1-beta-D-ribofuranosyl-4(5H)-oxopyrazolo[3, 4-d]pyrimidine-3-thiocarboxamide. All of these compounds were tested in vitro against certain viruses and tumor cells. Among these compounds, the guanosine analogues 7a and 20a showed significant activity against measles in vitro and were found to exhibit moderate antitumor activity in vitro against L1210 and P388 leukemia. 6-Azacadeguomycin and all other compounds were inactive against the viruses and tumor cells tested in vitro.     

滇藏荨麻根中化学成分的分离与鉴定

目的研究荨麻属植物滇藏荨麻的化学成分。方法运用硅胶柱色谱、薄层色谱、制备薄层色谱S、ephadex LH-20柱色谱等方法进行分离纯化,通过理化性质和1H-NMR1、3C-NMR、EI-MS等数据以及与对照品对照等方法进行结构鉴定。结果从滇藏荨麻根分离得到10个化合物,分别鉴定为:豆甾-4-烯-3-酮(1)、4-羟基反式桂皮酸(2)、4-羟基苯甲醛(3)、4-甲氧基苯甲酸(4)、4-羟基苯甲酸(5)、己二酸(6)、二十四烷酸甲酯(7)、2-羟基二十四烷酸甲酯(8)、胡萝卜苷(9)、β-谷甾醇(10)。结论化合物1~10均为首次从滇藏荨麻中分离得到,其中化合物4、6~8为首次从荨麻属植物中分离得到。     

Synthesis and analgesic activity of 2-methyl-2-[1-(3-benzoyl-4-substituted-1,4-dihydropyridyl)]acetic acid methyl esters, acetic acids, and acetamides.

A group of 2-methyl-2-[1-(3-benzoyl-4-substituted-1,4-dihydropyridyl)]acetic acid methyl esters (7), weak acetic acids (8), and acetamides (9) were designed for evaluation as less acidic non-ulcerogenic non-steroidal antiinflammatory drugs (NSAIDs). In this respect, the model compound 2-methyl-2-[1-(3-benzoyl-4-phenyl-1,4-dihydropyridyl)]acetic acid (8a), unlike traditional arylacetic acid NSAIDs, was shown to be a weak acid with a pKa of 9.17. In contrast to arylacetic acid NSAIDs, the alpha-methylacetic acid sodium salt of 8a, or the methyl alpha-methylacetate ester (7a) did not inhibit cyclooxygenase-1 (COX-1) or -2 (COX-2). In vitro stability studies showed that the methyl alpha-methylacetate ester (7a) acts as a prodrug to the alpha-methylacetic acid derivative (8a), undergoing rapid (< 10 minutes) and quantitative conversion upon incubation with rat plasma, or incubation with rat liver homogenate (t1/2 = 25 min). In contrast, the alpha-methylacetamide (9a) underwent negligible (< 2%) conversion to the alpha-methylacetic acid derivative (8a) upon incubation with either rat plasma, or rat liver homogenate, for incubation times up to 24 h. The effect of a C-3 para-substituted-benzoyl substituent (R1 = H, Cl, Me), a C-4 substituent (R2 = aryl, benzyl, cyclohexyl, alkyl), and the nature of the N1-acetic acid moiety [methyl ester (R3 = OMe), acetic acid (R3 = OH), acetamide (R3 = NH2)] on analgesic activity was determined using the 4% NaCl-induced abdominal constriction (writhing) assay. Compounds 7-9 inhibited writhing 27-95% relative to the reference drug aspirin (58% inhibition). The analgesic potency with respect to the para-benzoyl substituent was H > Cl or Me. Although the effect of the C-4 R2-substituent on analgesic activity was variable within the ester, acid and amide sub-groups of compounds, compounds having a R2-cyclohexyl substituent generally provided superior analgesic activity relative to those having a lipophilic alkyl substituent. The nature of the R3-substituent (OMe, OH, NH2) was a determinant of analgesic activity where the potency order was acetic acid methyl ester > acetic acid or acetamide, except when the C-4 R2-substituent was cyclohexyl or benzyl where the potency order was acetamide > acetic acid methyl ester or acetic acid. Reduction of the 5,6-olefinic bond of the 1,4-dihydropyridyl compound (9a, 94% inhibition) to the corresponding 1,2,3,4-tetrahydropyidyl derivative (10, 69% inhibition) reduced analgesic activity.     

Quantitative structure-metabolism relationships for substituted benzoic acids in the rat. Computational chemistry, NMR spectroscopy and pattern recognition studies.

An extensive set of computed molecular properties, both steric and electronic, have been calculated using molecular orbital and empirical methods for benzoic acid (1) and a congeneric series of substituted benzoic acids, i.e. 2-, 3- and 4-fluorobenzoic acids (2-4), 2-, 3- and 4-trifluoromethyl benzoic acids (5-7), 2-, 3- and 4-methylbenzoic acids (8-10), 4-amino benzoic acid (11), 2-fluoro-4-trifluoromethyl benzoic acid (12), 4-fluoro-2-trifluoromethyl benzoic acid (13), 3-trifluoromethyl-4-fluorobenzoic acid (14). We have monitored the urinary excretion profiles and determined the metabolic fate of compounds 2-7, 12-14 in the rat using high resolution 1H and 19F NMR spectroscopy. Corresponding data for compounds 1,8-11 are taken from the literature. In all cases phase II glucuronidation or glycine conjugation reactions dominated the metabolism of these compounds. Compounds 5, 7, 12, 13 have ester glucuronides as their major metabolites; the rest primarily form glycine conjugates. Compounds (1-12) have been classified according to their calculated physicochemical properties using pattern recognition methods and principal components maps have been used as a novel type of structure-metabolism diagram. The maps of compounds in the physicochemical property space served to separate the compounds into the two major classes which related to their principal metabolic fate in vivo, namely glucuronidation versus glycine conjugation. Compounds 13 and 14 were used as further probes of the property space, and dominant metabolic fates of glucuronidation and glycine conjugation, respectively, were predicted from the previous "training set map". The metabolic fate of compounds 1-14 can thus be classified according to a simple set of physicochemical rules. Investigation of the physicochemical properties which are important in distinguishing the metabolic fate of the compounds may give insight into key features of the drug-metabolizing enzyme active sites and hence provide information on basic mechanisms of benzoate metabolism.     

Preparation of protected peptide amides using the Fmoc chemical protocol

Different resins were examined for their potential use in the solid phase synthesis of protected peptide amides using the 9-fluorenylmethoxycarbonyl (Fmoc) chemical protocol. The model protected peptide amide BocTyr-Gly-Gly-Phe-Leu-Arg(Pmc)NH₂ (1) was synthesized on both the acid-labile 4-(2′,4’-dimethoxyphenyl-Fmoc-aminomethyl)phenoxy resin (Rink amide resin) (2) and on resins containing the base-labile linker 4-hydroxymethylbenzoic acid. Of the resins examined only the methylbenzhydrylamine resin containing the 4-hydroxymethylbenzoic acid linkage, which was cleaved by ammonolysis in isopropanoll, gave the model peptide 1 in good overall yield (53% including functionalization). Thus the synthesis of protected peptide amides by solid phase synthesis using Fmoc-protected amino acids with t-butyl-type side chain protecting groups is feasible. The choice of peptide-resin linkage and its cleavage conditions, however, are critical to the success of such syntheses. The potential application of this synthetic strategy to the preparation of novel peptide amides is discussed.     

Synthesis, in vitro anti-breast cancer activity, and intracellular decomposition of amino acid methyl ester and alkyl amide phosphoramidate monoesters of 3'-azido-3'-deoxythymidine (AZT)

We report the synthesis and anticancer activity of a series of AZT phosphoramidate monoesters containing amino acid methyl ester (3a-11a) and N-alkyl amide (3b-11b, 9c-9f) moieties. The aromatic amino acid methyl esters were found to be more cytotoxic than the aliphatic analogues toward MCF-7 cells (human pleural effusion breast adenocarcinoma cell line). A marked stereochemical preference for the L-amino acid stereochemistry was also observed in MCF-7 cells. There was no consistent enhancement of cytotoxicity of the methyl amides over the corresponding methyl esters. AZT and the two AZT aromatic amino acid methyl ester phosphoramidates 8a and 9a were found to be more cytotoxic toward MCF-7 cells than to CEM cells (human T-cell lymphoblastic leukemia). The selective cytotoxicity toward MCF-7 cells may be associated with greater intracellular levels of phosphoramidate monoester and/or phosphorylated AZT.     

Synthesis of the antileukemic compound N,N(11)-[5-[bis(2-chloroethyl)amino]-1, 3-phenylene]bisurea.

Conversion of 5-nitro-1, 3-benzenedicarboxylic acid (1) to the diamide 2 followed by hypochlorite rearrangement to the idamine 3 and subsequent reaction with acetic anhydride gave the bisacetamide 4. Reduction to the amine 5 followed by treatment with ethylene oxide formed the diol 6. The latter was converted to the bistosylate 7, which undrewent facile displacement with lithium chloride in acetone to give the mustard 8. Removal of the acetyl groups with hydrochloric acid gave 9, which reacted with potassium cyanate to provide the bisurea 10. In an alternative, but less satisfactory synthesis of 10, the compound (5-nitro-1, 3-phenylene) biscarbamic acid diphenyl ester (11), or the corresponding diethyl ester 12, was converted by ammonolysis to 13. The nitrodiurea 13 was next reduced to the amine 14, the hydrochloride of which reacted with ethylene oxide to give the diol 15. Treatment of the latter in dimethylformamide with N-chlorosuccinimide in the presence of triphenylphosphine gave 10 in low yield. The nitrogen mustards 8, 9 and 10 showed significant antitumor activities against P388 lymphocytic leukemia in mice.     

荔枝草的化学成分

目的对荔枝草(Salvia plebeiaR Br.)全草体积分数为70%的乙醇溶液溶液提取物的化学成分进行研究。方法利用制备薄层色谱、反复硅胶、Sephadex LH-20和开放ODS柱色谱等方法进行分离纯化;根据理化性质及波谱分析对分离得到的化合物进行结构研究。结果分离得到9个化合物,分别鉴定为β-谷甾醇(β-sitosterol,1)、高车前素(hispidulin,2)、鼠尾草酚(carnosol,3)、rosmadi-al(4)、熊果酸(ursolic acid,5)、柳穿鱼黄素(pectolinarigenin,6)、表迷迭香酚(epirosmanol,7)、咖啡酸甲酯(caffeic acid methyl ester,8)、东莨菪素(scopoletin,9)。结论化合物8、9为首次从该属植物中分离得到,化合物3-7为首次从该植物中分离得到。     

海洋细菌Bacillus sp.次生代谢产物的分离与鉴定

目的研究1株海洋细菌Bacillus sp.(No.DY1979)的次生代谢产物。方法采用各种色谱手段进行分离和纯化,根据各种光谱技术对单体化合物进行结构鉴定。结果分得12个化合物,分别鉴定为2,2′-二硫代二苯并噻唑(2,2′-dibenzothiazolyl disulfide,1)、2(3H)-苯并噻唑酮(2(3H)-benzothiazolone,2)、环(甘-脯)二肽(cyclo(Gly-Pro),3)、环(亮-脯)二肽(cyclo(Leu-Pro),4)、环(甘-丙)二肽(cyclo(Gly-Ala),5)、色氨酸(tryptophan,6)、1,2,3,4-四氢-3-羧基-2-卡波林(1,2,3,4-tetrahydro-3-carboxy-2-carboline,7)、胸腺嘧啶(thymine,8)、尿嘧啶(uracil,9)、苯乙酸(phenylace-tic acid,10)、邻苯二甲酸二异丁酯(1,2-benzenedicarboxylic acid diisobutyl ester,11)、邻苯二甲酸二正丁酯(1,2-benzenedicarboxylic acid dibutyl ester,12)。结论化合物1、2为含硫含氮的杂环类化合物,化合物1为细菌中首次分离,化合物2曾从另一株海洋细菌中分离得到;化合物3~9为含氮成分,其中化合物3~5为常见的细菌代谢产物环二肽,化合物6、7属氨基酸及其衍生物。     

Synthesis of substituted dipeptide GB-115 as a potential selective anxiolytic

A new potential selective anxiolytic GB-115 [N-(6-phenylhexanoyl)glycyl-L-tryptophan amide] has been prepared. The optimum method for GB-115 synthesis consists of five steps: (1) phenylhexanoylchloride synthesis using thionyl chloride; (2) glycine acylation with the resulting chloride under alkaline conditions at 0°C; (3) L-tryptophan esterification using thionyl chloride at room temperature; (4) N-(6-phenylhexanoyl)glycyl-L-tryptophan ethyl ester synthesis by the mixed anhydride method in dimethylformamide using isobutylchloroformate; (5) ammonolysis of the resulting dipeptide ester with gaseous ammonia in methanol. The activated ester and carbodiimide methods were also studied in addition to the mixed anhydride method with various solvents and different ways of product extraction.     

Phytotoxic compounds from Xanthocephalum gymnospermoides var. eradiatum

Investigation of the aerial parts of Xanthocephalum gymnospermoides var eradiatum led to the isolation of two new labdane-type of diterpenes, namely, 8 alpha,13S-epoxylabdane-14S,15-diol (1) and methyl grindelate (2). In addition, grindelic acid (3), 7 alpha, 8 alpha-epoxygrindelic acid (4), 7 alpha-hydroxy-8(17)dehydrogrindelic acid (5), 17-hydroxygrindelic acid (6) and 4,5-epoxy-beta-caryophyllene (7) were obtained. The isolated compounds were characterized by spectral means. The absolute configuration of compound 1 was established by chemical correlation with 8 alpha,13S-epoxy-15-nor-labdan-14-oic acid methyl ester of known absolute stereochemistry and by using the advanced Mosher's ester methodology. The results of the present investigation indicated that the known compound barbatol (8) could be an enantiomer of compound 1. Compounds 1-3 and 7 caused significant inhibition of the radicle growth of seedlings of Amaranthus hypochondriacus.     

Synthesis and calcium channel antagonist activity of dialkyl 1,4-dihydro-2,6-dimethyl-4-(pyridinyl)-3,5-pyridinedicarboxylates

The Hantzsch condensation of alkyl acetoacetates 3 with methyl 3-aminocrotonate (4) and pyridinecarboxaldehydes 5 afforded the unsymmetrical alkyl methyl 1,4-dihydro-2,6-dimethyl-4-(pyridinyl)-3,5-pyridinedicarboxylates 6, whereas condensation of 3 with 5 and ammonium hydroxide gave the symmetrical dialkyl 1,4-dihydro-2,6-dimethyl-4-(pyridinyl)-3,5-pyridinedicarboxylates 7. The calcium channel antagonist activities of disubstituted 1,4-dihydro-3,5-pyridinedicarboxylates 6,7, and 9 were determined with use of the muscarinic-receptor-mediated Ca2+-dependent contraction of guinea pig ileal longitudinal smooth muscle. The relative potency order for isomeric pyridinyl analogues 6 and 7 was 2-pyridinyl greater than 3-pyridinyl greater than 4-pyridinyl. Increasing the size of the alkyl ester substituents enhanced activity. Compounds having nonidentical ester substituents were more potent than those having identical ester substituents. Replacement of the C-3 and/or C-5 ester substituent(s) by a cyano substituent(s) decreased activity significantly. An approximate 1:1 correlation between the IC50 value for inhibition of [3H]nitrendipine binding and inhibition of the tonic component of the muscarinic-induced contractile response was observed. The test results suggest that a 4-(pyridinyl) substituent is bioisosteric with a 4-(nitrophenyl) substituent on a 1,4-dihydropyridine ring system where o-, m-, and p-nitrophenyl are bioisosteric with 2-pyridinyl, 3-pyridinyl, and 4-pyridinyl, respectively.     

薄荷乙酸乙酯提取部位的化学成分

从薄荷乙酸乙酯提取部位分离鉴定了8个化合物,分别为委陵菜酸（tormenticacid,1）,野椿酸（eusc叩hicacid,2）,乌,$-@（ursolicacid,3）,齐墩果酸（oleanolicacid,4）,尿嘧啶（uracil,5）,琥珀酸（succinicacid,6）,（9E）-8,11,12-trihydroxyoctadecenoicacidmethylester（7）,neoechinulinA（8）。化合物1,2,5,6为首次从该植物中分到;7和8为在唇形科中首次分到。     

Synthesis and structural characterization of derivatives of 2- and 3-benzo[b]furan carboxylic acids with potential cytotoxic activity

Derivatives of 2- and 3-benzo[b]furancarboxylic acids were prepared and evaluated for their cytotoxic potential in the National Cancer Institute, Bethesda, USA. Six compounds: 7-acetyl-6-hydroxy-3-methyl-2-benzofurancarboxylic acid (2), 6-hydroxy-7-(p-methoxycinnamoyl)-3-methyl-2-benzofurancarboxylic acid (4), 5-bromo-7-hydroxy-6-methoxy-2-benzofurancarboxylic acid methyl ester (6a), 6-acetyl-5-(O-ethyl-2'-diethylamino)-2-methyl-3-benzofurancarboxylic acid methyl ester (1f), 6-(O-ethyl-2'-diethylamino)-7-p-methoxycinnamoyl)-3-methyl-2-benzofurancarboxylic acid methyl ester hydrochloride (4b), 5-bromo-7-(O-ethyl-2'-diethylamino)-6-methoxy-2-benzofurancarboxylic acid methyl ester (6b) showed significant cytotoxic activities against human cancer cell lines. In addition the crystal structures of 7-methoxy-2-benzofurancarboxylic acid methyl ester (7a) has been solved by X-ray structure analysis of single crystals.     

Free radical oxidation of (E)-retinoic acid by the Fenton reagent: competing epoxidation and oxidative breakdown pathways and novel products of 5,6-epoxyretinoic acid transformation

The nature of the products formed by reaction of all-trans retinoic acid (1) and its major metabolite, 5,6-epoxyretinoic acid (2), with the Fenton reagent was investigated. Oxidation of 1 in a vigorously stirred biphasic medium (0.1 M phosphate buffer, pH 7.4/ethyl acetate 5:1 v/v) with Fe2+/EDTA complex (2 mol equiv) and a 10-fold excess of H2O2 proceeded smoothly to give a very complex mixture of products. Repeated TLC fractionation of the reaction mixture after methylation allowed isolation of the main products which were identified as 2 methyl ester, (7E)-7,8-epoxyretinoic acid methyl ester (6), all-(E)-2,6-dimethyl-8-(2,6,6-trimethyl-2-cyclohexen-1-ylidene)-2,4,6-octatrienal (11), the novel (9E)-5,6,9,10-diepoxyretinoic acid methyl ester (7), and (9Z)-5,6,9,10-diepoxyretinoic acid methyl ester (8) (1:1 mixture of syn/anti isomers each), 5,6-epoxy-beta-ionone (9), 5,6-epoxy-beta-ionylideneacetaldehyde (10), and trace amounts of beta-ionone (12), beta-ionylideneacetaldehyde (13), and 4-oxoretinoic acid (3) methyl ester. When the oxidation was carried out with the substrate and the Fenton reagent at concentrations as low as 10 microM, the main detectable products were 2 methyl ester, 11, and 7/8. Under similar conditions, the epoxide 2 gave mainly products 7-10. A less efficient conversion of 1 and 2 but similar product patterns were observed with other oxidizing systems such as peroxidase/H2O2 and 13-hydroperoxyoctadecadienoic acid in the presence of Fe(II). Besides providing the first detailed insight into the products formed by reaction of a retinoid with the Fenton reagent, the results of this study disclose a novel nonenzymatic route from 1 to the epoxide 2 and offer an improved chemical basis to inquire into the mechanism of the antiinflammatory, antimutagenic, and cancer chemopreventive action of these retinoids.     

Synthesis of some indole derivatives with potential antiinflammatory activity

2-Methylindole-3-acethydrazide (1) was reacted with arylisothiocyanate to give the corresponding 4-arylthiosemicarbazides 2a-d. Cyclization of the latter gave the corresponding 3-mercapto-5-[3-(2-methylindolyl)methyl]-1,2,4-triazoles 3a-d. Compounds 3a-c reacted with chloroacetic acid to give the corresponding indolyl-1,2,4-triazolythioglycolic acids 4a-c. The methylmercapto derivative 5 was also obtained from 3a and methyliodide. The hydrazide 1 was also reacted with carbon disulfide to give the corresponding indolymethyl-1,3,4-oxadiazole-2-thione (6) which was condensed with piperidine and formaldehyde to give the corresponding Mannich base 7. Condensation of 1 with aromatic aldehydes gave the corresponding hydrazones 8a-c which were converted into the corresponding oxadiazolines 9a-c.     

4-Anilino-6,7-dialkoxyquinoline-3-carbonitrile inhibitors of epidermal growth factor receptor kinase and their bioisosteric relationship to the 4-anilino-6,7-dialkoxyquinazoline inhibitors

The synthesis and SAR of a series of 4-anilino-6, 7-dialkoxyquinoline-3-carbonitrile inhibitors of epidermal growth factor receptor (EGF-R) kinase are described. Condensation of 3, 4-dialkoxyanilines with ethyl (ethoxymethylene)cyanoacetate followed by thermal cyclization gave, regiospecifically, 6,7-dialkoxy-4-oxo-1, 4-dihydroquinoline-3-carbonitriles. Chlorination (POCl(3)) followed by the reaction with substituted anilines furnished the 4-anilino-6, 7-dialkoxyquinoline-3-carbonitrile inhibitors of EGF-R kinase. An alternate synthesis of these compounds starts with a methyl 3, 4-dialkoxybenzoate. Nitration followed by reduction (Fe, NH(4)Cl, MeOH-H(2)O) gave a methyl 2-amino-4,5-dialkoxybenzoate. Amidine formation using DMF-acetal followed by cyclization using LiCH(2)CN furnished a 6,7-dialkoxy-4-oxo-1,4-dihydroquinoline-3-carbonitrile, which was transformed as before. Compounds containing acid, ester, amide, carbinol, and aldehyde groups at the 3-position of the quinoline ring were also prepared for comparison, as were several 1-anilino-6,7-dimethoxyisoquinoline-4-carbonitriles. The compounds were evaluated for their ability to inhibit the autophosphorylation of the catalytic domain of EGF-R. The SAR of these inhibitors with respect to the nature of the 6,7-alkoxy groups, the aniline substituents, and the substituent at the 3-position was studied. The compounds were further evaluated for their ability to inhibit the growth of cell lines that overexpress EGF-R or HER-2. It was found that 4-anilinoquinoline-3-carbonitriles are effective inhibitors of EGF-R kinase with activity comparable to the 4-anilinoquinazoline-based inhibitors. A new homology model of EGF-R kinase was constructed based on the X-ray structures of Hck and FGF receptor-1 kinase. The model suggests that with the quinazoline-based inhibitors, the N3 atom is hydrogen-bonded to a water molecule which, in turn, interacts with Thr 830. It is proposed that the quinoline-3-carbonitriles bind in a similar manner where the water molecule is displaced by the cyano group which interacts with the same Thr residue.