建立具有药物代谢酶CYP2C9活性的微生物模型

 目的研究短刺小克银汉霉AS 3.910体外模拟人体细胞色素P450(CYP)2C9的能力,建立具有CYP2C9活性的微生物模型。方法选用3种人体CYP2C9代谢的药物格列本脲、双氯芬酸和吲哚美辛为底物,利用液相色谱-质谱联用技术检测药物代谢产物的种类和转化率。结果通过调节转化培养基的种类和初始pH,使转化系统在较高底物浓度下具有良好的转化效果,格列本脲、双氯芬酸和吲哚美辛总转化率分别为90%,100%和83%,而且形成的主要转化产物与人体CYP2C9产生的主要代谢产物相同。结论短刺小克银汉霉AS 3.910具有CYP2C9代谢酶活性,是研究人体CYP2C9药物代谢适宜的体外模型。     

华根霉和雅致小克银汉霉对青蒿素的生物转化研究

目的：探讨微生物对青蒿素（I）的转化作用。方法：通过华根霉和雅致小克银汉霉在土豆培养基中发酵产酶，对青蒿素进行转化。结果：两株菌对底物均有转化作用，分离出去氧青蒿素deoxyartemisinin（Ⅱ），3α羟基去氧青蒿素3α-hydroxydeoxyartemisinin(Ⅲ）和9β－羟基青蒿素9β-hydroxyartemisinin(Ⅳ）共3个产物，其中Ⅳ为一新化合物，同时振荡条件下底物在无菌培养基中也能发生微量转化得到产物Ⅱ。结论：青蒿素易被实验两株真菌转化，同时过氧桥也易断裂而失去一个氧原子成为去氧青蒿素，丧失抗疟活性，起作用的可能是土豆培养基中的铁元素。     

小克银汉霉属微生物模型在体外药物代谢研究中的应用

药物代谢在药效和安全性评价中是非常重要的,而利用微生物转化为药物体外代谢模型则具有很多优势。小克银汉霉属的许多菌株具有与人体类似的Ⅰ相和Ⅱ相药物代谢酶,其微生物模型能对多种底物进行高效转化。本文对其在药物代谢方面的应用进行综述,并对其未来的发展进行了展望。     

A fatal case of disseminated zygomycosis associated with the use of blood glucose self-monitoring equipment

We report a fatal case of disseminated zygomycosis due to Cunninghamella bertholletiae in a 68-year-old man with myelodysplasia and type II diabetes mellitus, receiving desferrioxamine therapy for iron overload secondary to multiple transfusions. It is thought that he acquired the infection through the use of blood glucose self-monitoring equipment.     

Native aortic valve vegetative endocarditis with Cunninghamella.

Cunninghamella bertholletiae is a rare Mucor species that is seldom the cause for endocarditis of prosthetic heart valves. It is even a more uncommon cause of endocarditis of native heart valves. We present a case of Cunninghamella endocarditis of a native aortic valve in an immuno-compromised patient, diagnosed from tissue culture obtained at the time of surgery. There have only been two other reported cases of native valve endocarditis with a Mucor species, and in those cases, the diagnoses were made post-mortem.     

Microbial biotransformation of cryptotanshinone by Cunninghamella elegans and its application for metabolite identification in rat bile

Cryptotanshinone (1) is one of the major bioactive constituents in Salvia miltiorrhiza Bunge. Preparative-scale biotransformation of cryptotanshinone by Cunninghamella elegans (AS 3.2082) produced three new products, which were identified as (3R,15R)-3-hydroxycryptotanshinone (2), (3S,15R)-3-hydroxycryptotanshinone (3), and (4S,15R)-18-hydroxycryptotanshinone (4), respectively. The structural elucidation was based primarily on 1D and 2D NMR and HR-ESI-MS analyses. The absolute configuration of these three products was confirmed by comparison of their circular dichroism spectra with those of the known compounds. These biotransformed metabolites were used as for the comparison of in vivo metabolites in rat bile sample after intravenous administration and they are identical to three of the minor hydroxylated metabolites in vivo, which suggested that microbial biotransformation model was a useful and feasible approach for the preparation of mammalian metabolites in trace.     

Biotransformation of podophyllotoxin to picropodophyllin by microbes

Biotransformation of podophyllotoxin (PT) by several microbial species has been investigated. Among the fungi tested, it was found that Penicillium strains can isomerize PT to picropodophyllin (PPT) in 8% yield and other strains also transform the substrate into the same product but with lower yield.     

A microbial model of mammalian metabolism: biotransformation of 4,5-dimethoxyl-canthin-6-one using Cunninghamella blakesleeana CGMCC 3.970

1.?A filamentous fungus, Cunninghamella blakesleeana CGMCC 3.970, was applied as a microbial system to mimic mammalian metabolism of 4,5-dimethoxyl-canthin-6-one (1). Compound 1 belongs to canthin-6-one type alkaloids, which is a major bioactive constituent of a traditional Chinese medicine (the stems of Picrasma quassioides).

2.?After 72?h of incubation in potato dextrose broth, 1 was metabolized to seven metabolites as follows: 4-methoxyl-5-hydroxyl-canthin-6-one (M1), 4-hydroxyl-5-methoxyl-canthin-6-one (M2), canthin-6-one (M3), canthin-6-one N-oxide (M4), 10-hydroxyl-4,5-dimethoxyl-canthin-6-one (M5), 1-methoxycarbonl-β-carboline (M6), and 4-methoxyl-5-O-β-D-glucopyranosyl-canthin-6-one (M7).

3.?The structures of metabolites were determined using spectroscopic analyses, chemical methods, and comparison of NMR data with those of known compounds. Among them, M7 was a new compound.

4.?The metabolic pathways of 1 were proposed, and the metabolic processes involved phase I (O-demethylation, dehydroxylation, demethoxylation, N-oxidation, hydroxylation, and oxidative ring cleavage) and phase II (glycosylation) reactions.

5.?This was the first research on microbial transformation of canthin-6-one alkaloid, which could be a useful microbial model for producing the mammalian phase I and phase II metabolites of canthin-6-one alkaloids.

6.?1, M1?M5, and M7 are canthin-6-one alkaloids, whereas M6 belongs to β-carboline type alkaloids. The strain of Cunninghamella blakesleeana can supply an approach to transform canthin-6-one type alkaloids into β-carboline type alkaloids.     

短刺小克银汉霉对马钱子生物碱盐转化工艺的研究

目的 为提高短刺小克银汉霉对马钱子中马钱子碱与士的宁的转化率,构建高效的短刺小克银汉霉微生物转化体系。方法 根据菌种的生长代谢规律,采用单因素实验法,以马钱子碱硫酸盐和士的宁硝酸盐作为底物,以对底物的转化率作为指标,对可能的影响因素进行了考察。结果 获得了优化的转化工艺,即接种量为4%、发酵时间为2.5 d、底物质量浓度为20 mg/L、转化时间为3 d、培养温度为28 ℃、培养基初始pH值为6.5、摇床转速为150 r/min。在此工艺条件下,2种底物的平均转化率分别达到了77.75%与77.10%。结论 短刺小克银汉霉对2种底物的平均转化率分别提高了约17%与22%,此微生物转化体系能够满足马钱子减毒存效研究的需要。