5-氟胞苷和5''-脱氧-5-氟胞苷的合成

5-氟胞嘧啶经苯甲酰化保护后分别与供糖体四乙酰核糖和5-脱氧三乙酰核糖缩合,再经氨解,以45.7%和42.6%的收率分别制得5-氟胞苷和5'-脱氧-5-氟胞苷.     

5-氟胞苷和5＇-脱氧-5-氟胞苷的合成

5-氟胞嘧啶经苯甲酰化保护后分别与供糖体四乙酰核糖和5-脱氧三乙酰核糖缩合,再经氨解,以45.7%和42.6%的收率分别制得5-氟胞苷和5＇-脱氧-5-氟胞苷。     

Synthesis and biological activities of 5-trifluoromethyl-5'-azido-2',5'-dideoxyuridine and 5-trifluoromethyl-5'-amino-2',5'-dideoxyuridine.

5-Trifluoromethyl-2'-deoxyuridine (1) was tosylated with p-toluenesulfonyl chloride in dry pyridine at 3 degrees to give 5-trifluoromethyl-5'-O-(p-tolylsulfonyl)-2'-deoxyuridine (2), which was converted to 5-trifluoromethyl-5'-azido-2',5'-dideoxyuridine (3) by reacting with lithium azide in N,N-dimethylformamide at 85-90 degrees for 2 h. Compound 3 was then hydrogenated in ethanol-water (1:1, v/v) at room temperature and 35 psi of hydrogen pressure, using 10% palladium on charcoal as cstalyst, to yield 5-trifluoromethyl-5'-amino-2',5'-dideoxyuridine (4). Compound 4 is about fourfold less potent than compound 1 as an antiviral agent but is about 40-fold less toxic to the host Vero cells. Thus the therapeutic index of compound 1 has been improved by a factor of 10 by replacement of the 5'-hydroxyl with an amino group. Compound 1, however, is more than 100-fold more inhibitory to Sarcoma 180 cells in culture relative to compound 4. Compound 3 is markedly less potent than compound 1 or 4 as either an antiviral or an antineoplastic compound.     

Serotonin 5-HT3, 5-HT4, and 5-HT-M receptors

Serotonin (5-hydroxytryptamine [5-HT]) receptors can be classified either pharmacologically, into 5-HT1, 5-HT2, 5-HT3 and 5-HT4 receptors, or functionally, into G-protein-coupled receptors (5-HT1, 5-HT2, and 5-HT4) and ligand-gated ion channels (5-HT3). This article concentrates on the pharmacology, distribution, receptor-effector coupling, possible subtypes, and species differences of 5-HT3 receptors, which are equivalent to Gaddum and Picarelli's 5-HT-M receptor. Also presented here are some of the prominent features of the recently characterized 5-HT4 receptor. Although pharmacologic similarities have been suggested between 5-HT-M and 5-HT4 receptors (some potent 5-HT3 antagonists are active, with lower potency, at 5-HT4 receptors), it is clear that 5-HT4 receptors are different from 5-HT-M receptors.     

Antitumor agents. 5. synthesis, structure-activity relationships, and biological evaluation of dimethyl-5H-pyridophenoxazin-5-ones, tetrahydro-5h-benzopyridophenoxazin-5-ones, and 5h-benzopyridophenoxazin-5-ones with potent antiproliferative activity

New antiproliferative compounds, dimethyl-5H-pyrido[3,2-a]phenoxazin-5-ones (1-6), tetrahydro-5H-benzopyrido[2,3-j]phenoxazin-5-ones (7-9), and 5H-benzopyrido[3,2-a]phenoxazin-5-ones (10-12) were synthesized and evaluated against representative human neoplastic cell lines. Dimethyl derivatives 1-6 were more active against carcinoma than leukemia cell lines. The tetrahydrobenzo derivatives 7-9 were scarcely active, whereas the corresponding benzo derivatives 10-12 showed notable cytotoxicity against a majority of the tested cell lines. Molecular modeling studies indicated that the high potency of 10 and 11, the most cytotoxic compounds of the whole series, could be due to the position of the condensed benzene ring, which favors pi-pi stacking interactions with purine and pyrimidine bases in the DNA active site. Biological studies suggested that 10-12 have no effect on human topoisomerases I and II and that they induce arrest at the G2/M phase.     

Synthesis and antiretrovirus properties of 5'-isocyano-5'-deoxythymidine, 5'-isocyano-2',5'-dideoxyuridine, 3'-azido-5'-isocyano-3',5'-dideoxythymidine, and 3'-azido-5'-isocyano-2',3',5'-trideoxyuridine

The 5'-azidonucleosides 3 and 4 were obtained by treating thymidine and 2'-deoxyuridine with TPP/DEAD/HN3. The 3'-O-silylated 5'-azido-5'-deoxythymidine 5 and the corresponding 2'-deoxyuridine derivative 6 were transformed to the formamides (7 and 8, respectively) and dehydrated to the protected 5'-isocyano derivatives 9 and 10; deblocking gave 5'-isocyano-5'-deoxythymidine (11) and 5'-isocyano-2',5'-dideoxyuridine (12). 2,3'-Anhydro-5'-formamido derivatives of thymidine and 2'-deoxyuridine (19 and 20, respectively) were prepared by three different ways. In the most direct synthesis 3 and 4 were transformed to the 2,3'-anhydro-5'- azidonucleosides 17 and 18 by using TPP/DEAD; following the reaction with TPP/HCO2COCH3 gave 19 and 20. Nucleophilic opening reaction with LiN3 yielded the 3'-azido-5'-formylamino derivatives 21 and 22. Dehydration to 3'-azido-5'-isocyano-3',5'-dideoxythymidine (23) and 3'-azido-5'-isocyano-2',3',5'-trideoxyuridine (24) was achieved with tosyl chloride/pyridine. In contrast with 3'-azido-3'-deoxythymidine, compounds 11, 12, 23, and 24 were devoid of any marked inhibitory effect against DNA and RNA viruses including human immunodeficiency virus type I (HIV).     

去氧氟尿苷及其代谢物在肿瘤病人体内药代动力学研究

目的主要研究了去氧氟尿苷(5'-deoxy-5-fluridine)及其主要代谢物5-氟尿嘧啶在肿瘤病人体内的药代动力学特征.方法肿瘤病人口服800mg去氧氟尿苷胶囊,采用高效液相色谱法(HPLC)分别测定肿瘤病人体内中的去氧氟尿苷和其主要代谢物5-氟尿嘧啶的血药浓度.结果肿瘤病人体内去氧氟尿苷的血药浓度-时间曲线下面积AUC0-∞为6.45±1.71mg·h·L-1,末端相消除半衰期t1/2为0.65±0.23h,峰时间和峰浓度分别为1.00±0.37h和5.11±1.36mg·L-1.5-氟尿嘧啶的血药浓度-时间曲线下面积AUC0-∞为222.7±86.3μg·h·L-1,末段消除相的半衰期t1/2为0.65±0.50 h,峰时间tmax和峰浓度Cmax分别为的0.93±0.26h和199.11±89.14μg·L-1.比较不同肿瘤病人的药动学参数,胃癌病人对去氧氟尿苷的吸收与肝癌和结肠癌病人有差异,去氧氟尿苷在不同肿瘤病人体内代谢成5-氟尿嘧啶未见明显差异.结论去氧氟尿苷在三种肿瘤病人体内的吸收可能有差异,其主要药代动力学特征没见明显改变.     

New synthesis of 5-nitro- and 5-benzyloxytryptamine and their N-acylderivatives

By modifying the method of Abramovitch for preparation of tryptamine, a way to obtain N-acyl derivatives of tryptamine 3a-g without the necessity of isolating free tryptamine was found. The hydrolysis of the appropriate acyl derivatives gave 5-nitro- and 5-benzyloxytryptamines.     

Synthesis and antifolate evaluation of the 10-propargyl derivatives of 5-deazafolic acid, 5-deazaaminopterin, and 5-methyl-5-deazaaminopterin.

5-Deaza-10-propargylfolic acid (4), an analogue of the thymidylate synthase (TS) inhibitor 10-propargyl-5,8-dideazafolic acid (PDDF, 1), was prepared via alkylation of diethyl N-[4-(propargylamino)benzoyl]-L-glutamate (7) by 2-amino-6-(bromomethyl)-4(3H)-pyrido[2,3-d]pyrimidinone (15). Bromomethyl intermediate 15 was prepared from the corresponding hydroxymethyl precursor 14 by treatment with 48% HBr. Hydroxymethyl compound 14 was obtained by deamination of reported 2,4-diaminopyrido[2,3-d]pyrimidine-6-methanol (12a) in refluxing 1 N NaOH. Both 12a and its 5-methyl-substituted analogue 12b were converted to versatile 6-bromomethyl intermediates 13a and 13b from which important antifolates may be readily derived. Alkylation of 7 by 13a,b led to 10-propargyl-5-deazaaminopterin (5) and 5-methyl-10-propargyl-5-deazaaminopterin (6). As an inhibitor of TS from H35F/F cells, 4 gave an IC50 value showing it to be approximately 6-fold less inhibitory than PDDF (90 nM for 4 vs 14 nM for PDDF). In in vitro studies, IC50 (microM) values obtained for 4 vs L1210 and S180 of 1.50 and 2.35, respectively, were similar to those obtained for PDDF (2.61 and 1.97). Against HL60 cells, 4 was about 7-fold more cytotoxic than PDDF (IC50 values 0.72 and 5.29 microM). Inclusion of thymidine did not establish TS as the site of cytotoxic action for either 4 or PDDF in the cell lines used. In in vivo tests against L1210 in mice, 4 failed to show therapeutic effect. The 2,4-diamino compounds 5 and 6 were as potent inhibitors of DHFR from L1210 cells as MTX and 7- and 35-fold, respectively, more inhibitory than MTX toward L1210 cell growth. In mediated influx into L1210 cells, 5 and 6 were transported 2.7- and 8.5-fold, respectively, more readily than MTX. Against the EO771 mammary adenocarcinoma in mice, 6 produced greater antitumor effect than MTX. A dose of 36 mg/kg per day for 5 days caused no toxic deaths while the average tumor volume among 10 mice was reduced to 8-9% of that of the control, and 20% of the test animals were rendered tumor free.     

5-HT5 receptors

The 5-HT(5) receptor family consists of two members designated as 5-HT(5A) and 5-HT(5B). To date the 5-HT(5A) receptor has been identified in the mouse, rat, and human. The 5-HT(5B) receptor also is expressed in the mouse and rat, but not in the human where the coding sequence is interrupted by stop codons. Both receptors are essentially limited in distribution to the central nervous system (CNS), although the 5-HT(5A) receptor has also been found on neurons and neuronal-like cells of the carotid body. Within the CNS the 5-HT(5A) receptor shows a relatively broad distribution, while the 5-HT(5B) receptor has a very restricted distribution. The 5-HT(5A) receptor has been demonstrated to couple to G proteins, and the primary coupling appears to be through Gi/o to inhibit adenylyl cyclase activity. The 5-HT(5) receptors have not been extensively characterized pharmacologically. Both receptors show their highest affinity for LSD, which appears to act as a partial agonist at the 5-HT(5A) receptor. Amongst agonist-like molecules, 5-CT (5-carboxamidotryptamine) also has high affinity and has greater potency and affinity at the 5-HT(5A) receptor than does 5-HT itself. Both [(125)I]LSD and [(5)H]5-CT have been used as radioligands to study the receptors in vitro. Nothing is known about the role of the 5-HT(5B) receptor in vivo. A mouse line has been developed where the 5-HT(5A) receptor has been knocked out and these animals have been shown to have a diminished response to LSD-induced increases in locomotion. The 5-HT(5) receptors remain as two of the least studied and understood of the 5-HT receptor subtypes.