双菌多轮序列协同转化甾体制氢化可的松

建立了蓝色犁头霉AS 3．65和新月弯孢霉AS 3．4381协同多轮转化17α-羟基孕甾-4-烯-3,20-二酮-21-醋酸酯（RSA）割氢化可的松（hydrocortisone,HC）新工艺。在培养好的AS 3．65和AS 3．4381所组成的协同转化体系中,AS 3．65首先将RSA水解为脱氧皮质酮（RS）,这较AS 3．4381单轮批次转化省去了RSA到RS的化学水解工序。在甾体底物RSA平均投料质量浓度为1．3g/L和1g／L的条件下,所选定的协同转化体系可分别被重复利用3轮和6轮,相应的平均产率能维持在较高水平,分别高达81．6％和85％。另外,该工艺明显减少了底物RSA投料浓度对C11位羟化的影响,并有效抑制了AS 3．4381和AS 3．65单独转化过程中出现的14α—OH—RS和11α-OH—RS副产物．     

氢化可的松高产菌株新月弯孢霉的选育*

应用酮康唑抗性筛选法,将经过紫外线诱变处理的甾体11β-羟基化菌株——新月弯孢霉的原生质体倾注在含有酮康唑最小抑制浓度(10μmol/L)的再生培养基平板上,再生出136株酮康唑抗性突变株。其中氢化可的松转化率高于出发菌株的有14株,正向突变率达到10．3％,同时获得了氢化可的松转化率为出发菌株1．42倍的遗传稳定突变株KA-91。     

转化RSA为氢化可的松的新月弯胞霉筛选

从土样中筛选到 1株能转化甾体化合物 RSA(17α-羟基孕甾 - 4 -烯 - 3,2 0 -二酮 - 2 1-醋酸酯 )生成氢可的松 (11β,17α,2 1-三羟基孕甾 - 4 -烯 - 3,2 0 -二酮 )的 C4菌株 ,经菌落形态与个体形态观察 ,初步鉴定为新月弯胞霉 (curvularia lunata)。正交实验确定该菌株的最适培养基为 :葡萄糖 10 g,黄豆粉 10 g,自来水 10 0 0 m L,p H6 .5.经硅胶层析和高交液相色谱测定 ,氢化可的松     

甾体微生物转化C11β-羟基化的研究进展

C11β-羟基化是甾体微生物转化中难以实现的一步反应。对甾体C11β-羟基化的机理及部分生理生化问题进行了讨论,对蓝色犁头霉和新月弯孢霉催化转化甾体C11β-羟基化的应用研究特点及其催化转化反应产物氢化可的松的工业生产现状及相关问题进行了评述,并对此技术开发前景进行了预测。     

静息细胞连续两批次生物催化生产氢化可的松

以新月弯孢霉（Curvularia lunata）的Ⅱ级培养18h的活菌丝作为C11β位羟基化生物催化剂,在选定的含有微粒结晶甾体底物（0．2％,质量分数）17α,21-二羟基孕甾-4-烯-3,20-二酮的磷酸缓冲液（0．05mol／L,pH6．0）介质体系中,在经过连续两批次约55h的转化反应,底物转化率可维持在较高水平,产物氢化可的松净收率可达60％;从菌丝回收的底物RS可再利用。此工艺提高了生物催化剂的利用率,具有工业应用价值。     

用新月弯孢霉11β——羟基化16α——甲基化合物Rs—21醋酸酯

The conversion of 16 alpha-methyl-Reichstein's compound S 21-acetate (I) to 16 alpha-methyl-hydrocortisone (II) by the mycelium Curvularia lunata AS3.4381 was studied. Maximal 11 beta-hydroxylating activity of the mycelium was found during cultivation of the microorganism by 24h. Inhibition of the ethanol to the 11 beta-hydroxylating activity was obvious. The yield of 55.4% (II) (W/W) could be achieved during conversion of 0.15% substrate at 72 h.     

蓝色犁头霉原生质体的制备与再生

研究了氢化可的松生产菌蓝色犁头霉原生质体的形成与再生。通过对溶解酶系统的选择,影响原生质体形成的因素如渗透压稳定剂、酶浓度、菌龄、菌丝培养基和培养方式等因素进行考察,发现以0．4mol/L NH4Cl做为稳定剂、2．5mg/mL溶壁酶和5mg/mL纤维素酶组成的混合酶液溶解菌丝,4h后原生质体量可达10^6cell/mL。通过显微镜观察原生质体的形成过程以及在高渗培养基上的再生情况,再生率为15．6％。     

用新月弯孢霉11β-羟基化16a-甲基化合物RS-21醋酸酯

对新月弯孢霉AS3．4381的菌丝体转化16a-甲基Reicbstein's 化合物S21-醋酸酯(I)生成16a-甲基氢化可的松(II)进行了研究。培养24h的菌丝体的11β-羟基化活性最高;乙醇对此羟基化活性的抑制作用明显。当(1)浓度为0.15％,转化72h,产物(II)的重量收率为55.4％。     

甾体C11β—羟基生物转化菌株新月弯孢霉的筛选和鉴定

文章对甾体C11β－羟某化生物转化菌株－新月弯孢霉的生长和生物转化特征进行了研究。经过反复筛选,最终选出了一株氧化可的松转化率达30％的最优菌株。文中描述了新月弯孢霉菌体生长过程中,菌体干重与PH的变化情况,并通过正交实验确定了该菌株生长的最适培养基配方。经过研究,对新月弯孢霉菌株的生长和生物转化特性及其进行甾体C11β－羟基化生物转化过程有了初步的了解。     

高效液相检测醋酸氢化可的松杂质的方法建立

目的:建立高效液相法测定醋酸氢化可的松中杂质的检测方法。方法:采用色谱柱:Agela Venusil MP C18 4.6×250mm,流动相:磷酸盐缓冲液(取8mmol/L磷酸二氢钾溶液,用8mmol/L磷酸氢二钾溶液调节PH值至5.0,临用新制)-甲醇(62:38);检测波长:254nm;柱温:40℃测定。结果:采用此高效液相法能将杂质与主成分有效分离,专属性良好,准去度高,8小时内溶液较稳定,耐用性强,经检测限试验证明该方法能有效检出杂质。结论:该方法简便,准确度高,专属性好,建议采用高效液相法测定醋酸氢化可的松的杂质。     

Biotransformation of chinensiolide B and the cytotoxic activities of the transformed products

Biotransformation of chinensiolide B, 10α-hydroxy-1α,5α,15-H-3-oxoguaia-11(13)-en-6α,12-olide (1), yielded three selectively reduced products, 3β,10α-dihydroxy-1α,5α,15α-H-guaia-11(13)-en-6α,12-olide (2), 3α,10α-dihydroxy-1α,5α,15α-H-guaia-11(13)-en-6α,12-olide (3), and 3β,10α-dihydroxy-1α,5α,11β,15α-H-guaia-6α,12-olide (4) by the cell suspension cultures of Catharanthus roseus. 2 and 3 were also obtained from 1 incubated with cell cultures of a fungus Abisidia coerulea IFO 4011 and Platycodon grandiflorum, respectively. Among them, 2, 3 are two new compounds. The three products, 2–4, along with 1 were preliminarily evaluated for their in vitro cytotoxic activity against 3 cell lines (HepG2, WI-38 and VA-13) and all showed potent inhibitory effects on the cell proliferation. Of the four compounds, 3 was the most toxic to the three cell lines tested with IC₅₀ values of 22.7, 0.33 and 3.30 μM, respectively.     

一株产漆酶真菌新月弯孢霉JQH-100在染料脱色中的应用

从感染叶斑病的玉米叶片中分离、纯化得到一株高产漆酶的新月弯孢霉Curvularia lunata JQH-100菌株。液体培养Curvularia lunata JQH-100可产漆酶且活性较高,产酶高峰出现在第3天;以ABTS为底物粗酶液的最适反应温度是30℃,最适反应pH是2.8;染料脱色的研究表明,共培养体系对茜素红的脱色率达到了92.6%,对中性红和刚果红的脱色率也都在80%以上;Curvularia lunata JQH-100所产漆酶经纯化后对染料茜素红和刚果红有较高的脱色率,分别为82.1%和81.2%。研究结果显示Curvularia lunata JQH-100在染料废水处理中有较大应用潜力。     

玉米弯孢叶斑病菌ATMT突变株构建及致病力分析

利用农杆菌介导的基因转化(Agrobacterium-mediated transformation,ATMT)技术,转化玉米弯孢叶斑病菌 (Curvularia lunata),共获得转化子1 454个。对其中菌落形态、生长速率等性状有显著变化的8个突变株进行分析。通过离体叶片接种进行筛选,发现4个突变株致病性降低,2个突变株致病性增强。通过测定生长速率、产孢量及细胞壁降解酶活性发现,其中致病性减弱的突变株,其产孢量均有所下降甚至不产孢,突变株的PG酶活性普遍增强,但Cx酶活性没有明显变化,而2株强致病性突变株的Cx酶活性明显增强。     

11β-Hydroxylation of norethisterone acetate by Curvularia lunata

Abstract: The biotransformation of norethisterone acetate by Curvularia lunata was studied. The 11β-hydroxy-norethisterone acetate produced was identified by mass spectrometry, and ¹H and ¹³C nuclear magnetic resonance after extractive sample preparation.     

蓝色梨头霉菌体形态与生物转化率关系研究

研究了蓝色梨头霉菌丝球形态与产率的关系 :摇床转速为 170r min、pH值为 6 5、底物添加量为 0 1%、单位体积孢子数为 1× 10 7个 mL、(NH4 ) 2 SO4 质量分数为 0 9%～ 1 8%、采用回转式的培养方法时 ,菌体直径一般在0 79～ 1 39mm ,且菌丝缠绕不过于紧密 ,菌丝球边缘菌丝较长 ,各球体之间较独立 ,此时转化率为 5 1%～ 5 6 4 %。     

Ultrastructure and genotypic characterization of the filamentous fungus Cochliobolus lunatus in comparison to the anamorphic strain Curvularia lunata

Abstract Although Curvularia lunata is classified as a conidial anamorph of Cochliobolus lunatus , the electron microscopic studies revealed the ultrastructure of both strains to be significantly different. C. lunatus m118 grows in the hyphal form characterized by a thick cell wall and numerous lipid bodies. C. lunata forms thinner hyphae of various sizes and large oval spores. Electrophoretic karyotypes of C. lunatus m118 (this paper) and C. lunata AT46 (Osiewacz, H. and Ridder, R. (1991) Curr. Genet. 20, 151–155) as well as RAPD-PCR analysis with the primer (GTG)₅ indicate close genetic relationship of both microorganisms.     

吉林省部分玉米种质资源抗玉米弯孢菌叶斑病鉴定研究

玉米弯孢菌叶斑病主要是由弯孢菌（Curvularia lunata）引起的侵染性病害。近年来,该病害在我国玉米主产区发生面积逐年扩大,已成为玉米重要病害之一。本文研究了吉林省主要玉米杂交种和自交系抗病性差异,结果表明：玉米杂交种间以及自交系间抗病性差异明显;吉63、黄早4、自330、丹9046、丹9041、铁7922、掖478、沈5003、丹340和E28等一批应用多年的种质资源均为感病类型（MS-HS）;而新选育的各类群一些种质和具有热带、亚热带血缘的78599等一些外来种质资源均为抗病类型（R～HR）。杂交种的抗病性与双亲的抗病性有密切关系;玉米杂交种苗期较抗病,抽丝期极为感病,这表明杂交种抗性随植株生长而递减。     

Biotransformations of rifamycins: process possibilities

Rifampicin, an important antibiotic, is manufactured by chemical conversion of rifamycin S which is obtained by the chemical modification of rifamycin B. Rifamycin B is a product of Nocardia mediterranei fermentations. The chemical conversion of rifamycin B to rifamycin S has many disadvantages: Strong acidic conditions are required, heavy foam formation accompanies transformation and the yields are low. This review highlights the developments in alternative, biochemical transformations using enzymes and cells; the main focus is on transformations carried out by rifamycin oxidase.