Effect of L-cysteine on distribution volume of 1-(tetrahydro-2-furanyl)-5-fluorouracil

Higher plasma concentrations of 1-(tetrahydro-2-furanyl)-5-fluorouracil (FT) were obtained after administration of FT (100 mg/kg, i.v.) combined with L-cysteine (CySH, 500 mg/kg, p.o.). The volume of distribution (Vd) and body fluid volumes significantly decreased. These results suggest that the increase of the plasma concentrations of FT can be attributed to the decrease of the Vd of FT, which is considered to be based on the decrease of body fluid volumes by the combined administration of CySH.     

Studies to increase the antitumor activity of 1-(tetrahydro-2-furanyl)-5-fluorouracil and its metabolic aspects by combined administration with L-cysteine

The plasma and liver concentrations of both 1-(tetrahydro-2-furanyl)-5-fluorouracil (FT) and 5-fluorouracil (5-FU), an active metabolite of FT, increased very markedly after administration of FT (500 mg/kg, p.o.) combined with L-cysteine (L-CYS, 500 mg/kg, i.p. or p.o.) when compared to FT alone in rats. On the other hand, the oral acute toxicity of FT was also enhanced with the combined administration of FT and L-CYS. There was no difference in the in situ absorption rate of FT from the small intestine between rats treated with L-CYS (500 mg/kg, i.v.) and vehicle-treated controls. The inhibition of the disappearance of FT and the increase of the formation of 5-FU was observed in vitro after incubation of FT with liver microsomes from rats treated with L-CYS (500 mg/kg, p.o.) when compared to vehicle-treated controls. The presence of L-CYS significantly inhibited the in vitro degradation of 5-FU by non-treated rat liver homogenate. In the drug metabolizing enzyme activity of rat liver microsomes, aniline p-hydroxylase activity was inhibited, but aminopyrine N-demethylase activity was conversely activated by the combined administration of FT and L-CYS, but not by FT alone; furthermore, no change of cytochrome P-450 content was observed. In sarcoma 180 bearing mice, the oral antitumor activity of FT in combination with L-CYS (500 mg/kg, i.p. or p.o.) was about 1.1-2.0 times higher than that of FT alone. It was concluded from these findings that the drug metabolizing enzymes in liver involved in the conversion of FT into an active metabolite, 5-FU, are influenced by the combined administration of FT and L-CYS to give an increased organ level of 5-FU; and this resulted in the enhancement of the antitumor activity of FT.     

Studies of antitumor agents. 1. Resolution of racemic 1-(tetrahydro-2-furanyl)-k-fluorouracil into the R and S isomers and examination of the biological activities of the isomers.

1-(Tetrahydro-2-furanyl)-5-fluorouracil (Thf-FU), which is named Ftorafur or FT-207 and is used clinically as an antitumor agent, was conveniently synthesized by condensation of the trimethylsilyl derivative of 5-fluorouracil with 2-acetoxytetrahydrofuran using NaI as a catalyst. This optically inactive Thf-FU was resolved into optically active (R)-(+)- and (S)-(-)-Thf-FU in high optical purity and excellent yield by formation of diastereoisomers with brucine. 13C NMR data were obtained on Thf-FU and related compounds and the antibacterial activities and in vivo antitumor activities of these isomers were tested. The degradations of these isomers to 5-fluorouracil by liver microsomes were also examined. No significant differences were found in any of these properties of these isomers.     

Syntheses and antifungal activities of some 3-(2-phenylethyl)-5-substituted- tetrahydro-2H-1,3,5-thiadiazine-2-thiones.

Ten new 3-(2-phenethyl)-5-substituted-tetrahydro-2H-1,3,5-thiadiazine-2- thiones were synthesized by the reaction of phenylethylamine with carbon disulfide and potassium hydroxide, followed by formaldehyde and appropriate amino acids. The structures of these compounds have been confirmed by UV, IR, 1H-NMR and elementary analysis. The antifungal activities of the compounds were tested by tube dilution method against yeast-like fungi (Candida albicans, C. parapsilosis, C. stellatoidea and C. pseudotropicalis) and minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values were determined. All compounds proved to be highly effective against yeast-like fungi (MFC range: 1.56-12.5 micrograms/ml).     

Studies on antitumor agents. 8. Antitumor activities of O-alkyl derivatives of 2'-deoxy-5-(trifluoromethyl)uridine and 2'-deoxy-5-fluorouridine

O-Benzyl and O-ethyl derivatives of 2'-deoxy-5-(trifluoromethyl)uridine (F3Thd) and 2'-deoxy-5-fluorouridine (FUdR) were synthesized. The oral antitumor activity of the compounds against sarcoma 180 in mice was examined. The 5'-O-ethyl (3b), 3'-O-ethyl (3c), 5'-O-benzyl (3e), and 3'-O-benzyl (3f) derivatives of F3Thd were 4-fold more active than F3Thd itself. Among the substituted-benzyl derivatives of F3Thd, 3'-O-(p-chlorobenzyl)-F3Thd (3h) showed the highest activity, with an ED50 less than one-tenth of that of F3Thd. The activities of 5'-O-benzyl (7c) and 3'-O-benzyl (7d) derivatives of FUdR were equal to those of the effective O-alkyl derivatives of F3Thd.     

Metabolism of 1-(2-tetrahydrofuryl)-5-fluorouracil to 5-fluorouracil in partially hepatectomized rats.

Changes in the metabolism of 1-(2-tetrahydrofuryl)-5-fluorouracil (tegafur) to 5-fluorouracil (5-FU) were examined in the plasma, lung, liver, stomach, small intestine, spleen and kidney in two-thirds partially hepatectomized rats. Concentrations of tegafur and 5-FU in plasma and tissues were determined 30 min after injecting 100 mg/kg of tegafur via the tail vein. The 5-FU concentration in the plasma remained unchanged for the first 7 days after hepatectomy. The tissue level of 5-FU was higher in the liver and kidney than in other organs examined, but there were no changes in levels of 5-FU in each organ examined. Our observations support the proposal that the conversion of tegafur to 5-FU is maintained in partially hepatectomized rats.     

Synthesis of antimicrobial agents. 1. Syntheses and antibacterial activities of 7-(azole substituted)quinolones

A series of 6-fluoro- and 6,8-difluoro-7-(azole substituted)-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids were prepared. Structure-activity relationship studies indicated that the antibacterial potency was better when the 6,8-substituents were fluorine atoms and the 7-substituent was either 1-imidazolyl, 20, or 4-methyl-1-imidazolyl, 25. From the results of studies on pharmacokinetic profile and toxicity, 20 and 25 were found to possess excellent antibacterial activities and to show high blood levels after oral administration to mice with low toxicity.     

8-氨基-3-四氢呋喃甲基苯并吗吩烷的合成及药理活性

目的设计并合成与环佐辛有类似的阿片受体亲和活性、在体内具有较长作用时间的3-四氢呋喃甲基苯并吗吩烷类似物。方法8-三氟甲磺酸酯-3-四氢呋喃甲基苯并吗吩烷经催化氨化制得目标物，对目标物进行受体亲和力测定。结果8-氨基及8-苯氨基化合物在体外与μ,δ和κ受体的亲和力均较相应的8-羟基化合物低。结论目标化合物的体外受体亲和力相对较低，但此结果尚不能完全说明其在体内的作用情况及其可否用于毒品成瘾的治疗。进一步研究正在进行。     

Hypocholesterolemic activity of 1,3-bis(substituted phenoxy)-2-propanones.

A series of 1,3-bis(substituted phenoxy)-2-propanones was found to be active hypocholesterolemic agents at 10 mg/kg/day. The p-chloro- and p-methyl-substituted phenoxy compounds possess the highest activity. These compounds did not possess the estrogenic and antifertility activities of the related previously reported derivatives of the bis(beta-phenylethyl) ketone series. The 1,3-bis(p-methylphenoxy)-2-propanone (7) also lowered serum triglycerides and glycerol which appeared to be due to increased levels of serum lipase and reduced activity of liver lipase. There was reduced incorporation of free fatty acids into complex lipids by the liver. Cholesterol was excreted faster in the treated animals.     

Reactions of 1,3-bis(2-chloroethyl)-1-nitrosourea and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea in aqueous solution

Products formed from the reaction of two chloroethylnitrosoureas in neutral aqueous solution have been identified and quantified. Mixture components recovered after a 1-h incubation period accounted for 75--85% of the starting nitrosourea. Approximately 65--85% of the reaction products were formed by an initial cleavage of the nitrosourea to the proposed intermediates 2-chloroethyl azohydroxide and an isocyanate and by subsequent hydrolytic reactions. A minor pathway, 5--10% of products, involves denitrosation of the nitrosourea with oxazoline formation. Stable isotope labeling and mass spectrometry have been used to determine the reaction sequence and product origins. Reaction product identification has been made using high-performance LC isolation and comparison with synthetic material.     

Studies on beta-lactam antibiotics. III. Syntheses and antibacterial activities of new 3-(1,3-dithiolan-2-yl)cephalosporins, YM-22508, YM-16457 and their prodrug-type esters

The syntheses and biological activities of new 7-beta-[(Z)-2-(2-amino-4-thiazolyl)-2-hydroxy-iminoacetamido]-3-(1 ,3- dithiolan-2-yl)-3-cephem-4-carboxylic acid (YM-22508, 1a), 7-beta-[(Z)-2-(2-amino-4-thiazolyl)-2- methoxyiminoacetamido]-3-(1,3-dithiolan-2-yl)-3-cephem-4-carboxyli c acid (YM-16457, 1d) and their prodrug-type esters are described. Among them, YM-22561 (1c), the 1-acetoxyethyl ester of 1a, showed good in vivo efficacy in mice against infections of Staphylococcus aureus Smith, Streptococcus pyogenes S 23 and Escherichia coli NY-17 and a long plasma T1/2 in mice.     

N1-(芳)烷酰氧亚甲基-5-氟尿嘧啶的合成及其初步抗肿瘤活性的研究

目的　合成抗肿瘤活性高 ,毒性小的N1- (芳 )烷酰氧亚甲基取代的 5 -氟尿嘧啶衍生物。方法　以 5 -氟尿嘧啶为原料 ,经与甲醛加成反应后 ,和二酸单苄酯反应即得目标物 3a、3b、3c ,并采用MTT法及SRB法评价目标物 3的抗肿瘤活性。结果　合成了 3个目标物 3a、3b、3c ,其结构经1HNMR、IR和MS确证。结论　体外抗肿瘤活性筛选结果显示 3b和 3c有较强的抗肿瘤活性。