利福霉素B生物合成调控可能性研究

生物合成全过程的强化实际上是通过改变培养基配比、选种、优化发酵过程工艺条件实现的。现在这些强化微生物过程的传统方法,常作为发酵过程中直接反映发酵特性的补充手段。发酵过程中改变温度、通气量、搅拌转速、调节pH、补料、补水、加入前体等,本身就是一个生物合成控制过程。     

地中海诺卡氏菌利福霉素发色团的生物合成

地中海诺卡氏菌产生安莎类抗生素利福霉素B,利福霉素的结构由安莎链和发色团组成,这种发色团的七碳氨部分是安莎类抗生素安莎链形成的基础,并已鉴定为3-氨基-5羟基苯甲酸。Kibby等合成了[羧基-(14)C]-3-氨基-5-羟基苯甲酸,并指出这种标记化     

丙酸盐对大环内酯类抗生素M—90生物合成的调控

研究了如何通过加入前体来提高抗生素Ｍ－９０的产量，确定了最佳前体——丙酸盐及其加入的最适时间与浓度，考察了铵盐对前体的影响，并进一步探索了丙酸盐前体对Ｍ－９０产生菌生长代谢的作用。     

B—因子及其类似物对诺卡氏菌生物合成利福霉素的影响

自身提供的调节因子改善次级代谢的诱导,首先由灰色链霉菌产生链霉素的A—因子所证实。相关的γ—内酯化合物,L—因子和诱导因子分别是灰色链霉菌产生leucaemo-mycin和维及尼链霉菌产生维及尼霉素的自我调节因子。     

利福霉素的药理与临床

利福霉素的药效动力学目前已知Rif抗菌机制是,抑制细菌RNA聚合酶;而其抗肿瘤作用是,抑制病毒逆向转录酶和DNA聚合酶,这三种酶统称Rif的靶酶。 Rif和细菌RNA聚合酶,容易形成稳定的复合物,使RNA合成停止。利用RNA之放射性前体物之一~3H尿苷掺入菌体速度,可以间接测定菌体RNA聚合酶活性;研究中发现利福定(RFD)和利福平(RFP)与     

利福霉素类药物国内外研究情况综述

结核病对人类的危害已有数千年历史。80年代初,由于开展对结核病的短程化疗,使结核病受到很大程度的控制。但近年来,随着人免疫缺陷病毒（HIV）感染以及多药耐药菌的产生,使结核病再度蔓延。WHO宣布肺结核已处于一个全球的紧急状态,并号召制药行业多投资于寻找对付该疾病的新药的研究,WHO的P．Nunn博士说,有效的新药中,利福霉素急需进一步开发。我国60年代着手对利福霉素类药物进行研究,在临床应用研究方面领先于国外。先后研究成功并已上市的有利福平、利福定、利福喷丁,对利福哌啶、利福苯噻唑等品种的研究取得了较大的进…     

HPLC法测定利福霉素含量

目的：采用HPLC法测定利福霉素的含量。方法：以辛基硅烷键合硅胶为填充剂，甲醇一乙腈一0．075mol/L磷酸二氢钾溶液一1．0mol/L构橼酸溶液(45：12：28：5)紫外检测波长为255nm，流速0．8m1／min。结果：其线性范围20—140μg／ml，平均加样回收率为99．5％(RSDl．2％)。结论：本方法简单、快速。结果准确可靠。     

利福霉素类抗生素分析方法研究进展

本文对近15年来利福霉素类抗生素分析方法的研究进展进行了评述,其中包括薄层色谱法、高效液相色谱法、近红外漫反射光谱法、化学发光法、差示脉冲极谱法、毛细管电泳法及液相色谱-质谱联用技术等.     

地中海拟无枝酸菌原生质体电融合及其在提高利福霉素SV发酵效价中的应用

对产利福霉素SV的地中海拟无枝酸菌 (Amycolatopsismediterranei)原生质体进行热灭活和紫外灭活标记 ,其热灭活条件为 5 2℃ ,1.5h ,紫外灭活条件为紫外线照射 ( 15W ,2 5cm ,2 70nm) 6 0min。将双灭活标记的原生质体用CRY 3型细胞融合仪进行电融合 ,得出 :成串电流频率 1.5MHz ,电压 5 8V ,成串时间 2 0s ,融合脉冲幅宽 80 μS ,融合电压 5 0 0V ,融合槽间距 0 .5mm时 ,融合率最高为 9.3× 10 -4 。对筛选的融合子产量试验表明 ,5 0 %以上的融合子产量高于出发菌株 ,有明显的正变作用 ,将融合子在利福霉素代谢类似物平板上分离纯化 ,获得了化学效价提高 30 %以上的产量稳定菌株。     

Thioesterases and the premature termination of polyketide chain elongation in rifamycin B biosynthesis by Amycolatopsis mediterranei S699

The role of two thioesterase genes in the premature release of polyketide synthase intermediates during rifamycin biosynthesis in the Amycolatopsis mediterranei S699 strain was investigated. Creation of an in-frame deletion in the rifR gene led to a 30 approximately 60% decrease in the production of both rifamycin B by the S699 strain or a series of tetra- to decaketide shunt products of polyketide chain assembly by the rifF strain. Since a similar percentage decrease was seen in both genetic backgrounds, we conclude that the RifR thioesterase 2 is not involved in premature release of the carbon chain assembly intermediates. Similarly, fusion of the Saccharopolyspora erythraea DEBS3 thioesterase I domain to the C-terminus of the RifE PKS subunit did not result in a noticeable increase in the amount of the undecaketide intermediate formed nor in the amounts of the tetra- to decaketide shunt products. Hence, premature release of the carbon chain assembly intermediates is an unusual property of the Rif PKS itself.     

利用均匀实验优化利福霉素SV发酵培养基氮源配比

应用均匀设计的方法对利福霉素SV发酵培养基中的氮源配比进行优化。研究了氮源中各成分对发酵效价的影响。确定各成分的最佳配比并用实验验证，使摇瓶发酵效价提高了10％以上。并对利福霉素SV产生菌在新、老培养基中的代谢特性进行了比较。     

A genetic approach to the biosynthesis of the rifamycin-chromophore in Nocardia mediterranei. I. Isolation and characterization of a pentose-excreting auxotrophic mutant of Nocardia mediterranei with drastically reduced rifamycin production

The mutant under study, designated A8, is derived from a Nocardia mediterranei strain, N813, which is a high rifamycin B producer. A8 is auxotrophic for aromatic amino acids and produces much less rifamycin B than the parent. A mixture of pentoses with D (--) ribulose as the main product is accumulated in the fermentation broth of this mutant. It was shown to be affected in its transketolase activity as no formation of D-sedoheptulose -7P from pentose-phosphates could be detected in vitro using crude extracts. The only pathway so far known which is derived from D-sedoheptulose-7P is the shikimate pathway leading to aromatic amino acids and vitamins. Biochemical and genetic investigations with mutant A8, which is defective in both the biosynthesis of rifamycins and the biosynthesis of shikimate pathway products, show that the seven-carbon amino unit of the rifamycin-chromophore must be derived from an intermediate of the shikimate pathway.     

RP-HPLC法同时测定复方酮康唑乳膏中二组分的含量及有关物质检查

目的采用反相高效液相色谱法测定酮康唑乳膏中酮康唑和丙酸氯倍他索的含量及有关物质。方法色谱柱为Diamonsil C18柱(250mm×4.6mm,5μm);流动相为甲醇-水(74∶26);检测波长为239nm;柱温为35℃。结果酮康唑、丙酸氯倍他索和有关物质能获得基线分离。酮康唑在0.16~1.44g·L-1,丙酸氯倍他索在4·0~36mg·L-1范围内峰面积与质量浓度呈良好的线性关系,相关系数分别为0.9999和0.9995(n=5),平均回收率分别为101.4%和101.5%,RSD分别为0.7%和1.4%(n=9)。结论本法快速,准确,专属性好,可用于酮康唑乳膏中酮康唑和丙酸氯倍他索的含量测定及有关物质检查。     

The interaction of rifamycin SV with hepatic transport of taurocholic acid in the isolated perfused rat liver

Summary The effect of rifamycin SV on hepatic transport of taurocholic acid was investigated using isolated perfused rat liver technique. In all experiments, the perfused liver was maintained at taurocholic acid steady state by infusing constant amount of taurocholic acid.Infusion of rifamycin SV at various rates decreased biliary secretion of bile acids in a dose-dependent manner. Replacement of rifamycin SV by perfusion medium reversed this effect.To determine the site of action of rifamycin SV, kinetic experiments with ¹⁴C-taurocholic acid were undertaken. Rifamycin SV elevated the half-life of the medium disappearance of ¹⁴C-taurocholic acid. Furthermore, the antibiotic delayed the biliary appearance of ¹⁴C-taurocholic acid.The analysis of the results gave indications that the antibiotic interferred with hepatic uptake as well as biliary secretion of taurocholic acid.Part of this publication was presented in the 18. Frühjahrstagung der Deutschen Pharmakologischen Gesellschaft (1977)     

止喘灵口服液联合丙酸氟替卡松治疗儿童哮喘的临床研究

目的探讨止喘灵口服液联合丙酸氟替卡松治疗儿童哮喘的临床疗效。方法选择2018年2月—2019年2月在延安市人民医院治疗的哮喘患儿86例,根据用药的差别分为对照组(43例)和治疗组(43例)。对照组吸入丙酸氟替卡松吸入气雾剂,125μg/次,2次/d;治疗组在对照组基础上口服止喘灵口服液,10 mL/次,3次/d。两组均治疗1周。观察两组患者临床疗效,同时比较治疗前后两组患者症候积分,LCQ、PAQLQ、C-ACT和MARS-A评分,最大呼气流量(PEF)、用力肺活量(FVC)和一秒用力呼气容积(FEV1)值,及血清金属蛋白酶抑制因子1(TIMP1)、细胞间粘附分子-1(ICAM-1)、半胱氨酰白三烯(CysLTs)、降钙素原(PCT)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)水平。结果治疗后,对照组临床有效率为81.40%,显著低于治疗组的97.67%,两组比较差异有统计学意义(P0.05)。治疗后,两组患者喘息、咳嗽、咳痰及肺部啰音等症候积分均明显下降(P0.05),且治疗组症候积分明显低于对照组(P0.05)。治疗后,两组LCQ、PAQLQ、C-ACT和MARS-A评分均明显升高(P0.05),且治疗组这些评分明显高于对照组(P0.05)。治疗后,两组FEV1、FVC、PEF均明显升高(P0.05),且治疗组FEV1、FVC、PEF明显高于对照组(P0.05)。治疗后,两组血清TIMP-1、ICAM-1、CysLTs、PCT、IL-6、TNF-α水平均显著下降(P0.05),且治疗组血清TIMP-1、ICAM-1、CysLTs、PCT、IL-6、TNF-α水平明显低于对照组(P0.05)。结论止喘灵口服液联合丙酸氟替卡松吸入气雾剂治疗儿童哮喘可有效改善患儿临床症状,促进肺功能改善,提高生活质量,改善机体细胞因子水平,提高免疫。     

沙美特罗替卡松改善稳定期老年COPD患者肺功能及负性情绪的疗效分析

目的：探讨沙美特罗替卡松应用于老年慢性阻塞性肺疾病（COPD）患者稳定期的疗效。方法：选择本院2008年6月～2010年9月收治的80例稳定期老年COPD患者,随机分为研究组和对照组各40例,两组均给予COPD稳定期常规治疗,研究组在常规治疗的基础上给予沙美特罗替卡松吸入,治疗3个月后观察两组肺功能（FEV1/FVC,FEV1）改善及Zung抑郁评分（SDS）改变情况。结果：两组治疗前肺功能、抑郁评分比较,差异无统计学意义（P〉0.05）;与对照组治疗后相比,研究组肺功能指标明显升高,Zung抑郁评分明显降低,两组差异有统计学意义（P〈0.05）。结论：沙美特罗替卡松可减轻稳定期COPD患者的临床症状,改善肺功能,改善患者情绪状态,值得应用。     

Effect of reduced glutathione (GSH) on pharmacokinetics and distribution of rifamycin SV in rats

Changes of the pharmacokinetic parameters of rifamycin SV in the blood and changes of the antibiotic concentration in rat organs after its coadministration with glutathione in reduced form (GSH). in oxidized form (GSSG) and with the individual amino acids entering the tripedtide were studied. The use of reduced glutathione together with rifamycin was found to accelerate the distribution phase in the kinetics of the antibiotic in the blood by acceleration of transport of the drug from central compartment (blood) to tissue compartment (tissues), this being reflected by increased K₁₂ and K₁₂/K₂₁ values. Studies of the distribution of rifamycin in individual rat organs have shown GSH to significantly elevate the concentration of the antibiotic in the lungs with concomitant reduction of its level in the liver. The blocking of free sulfhydryl groups of glutathione by its use in oxidized form completely abolished this effect. The administration of rifamycin together with l-cysteine resulted in increased concentration of the antibiotic in both lungs and liver. The two other amino acids entering GSH —glycine and l-glutamic acid — did not cause any changes of rifamycin concentration in the organs. From these results it may be concluded that the mechanism of the observed effect of glutathione on rifamycin concentration differs in the lungs and liver though both effects are mediated by the free sulfhydryl groups of glutathione.