Bioconversion of n−3 and n−6 PUFA by <Emphasis Type="Italic">Clavibacter</Emphasis> sp. ALA2

Clavibacter sp. ALA2 oxidized n−3 and n−6 PUFA into a variety of oxylipins. Structures of products converted from EPA and DHA were determined as 15,18-dihydroxy-14,17-epoxy-5(Z),8(Z),11(Z)-eicosatrienoic acid and 17,20-dihydroxy-16,19-epoxy-4(Z),7(Z),10(Z),13(Z)-docosatetraenoic acid by GC-MS and NMR analyses. In contrast, γ-linolenic acid and arachidonic acid were converted to diepoxy bicyclic FA, tetrahydrofuranyl monohydroxy FA, and trihydroxy FA. Thus, the structures of bioconversion products were different between n−3 and n−6 PUFA. Furthermore, strain ALA2 placed hydroxy groups and cyclic structures at the same position from the ω-terminal despite the number of carbons in the chain and the double bonds in the PUFA.     

Biosynthetic pathway of diepoxy bicyclic FA from linoleic acid by Clavibacter sp. ALA2

The biosynthetic pathway of two bicyclic FA, 12∶17, 13∶17-diepoxy-9(Z)-octadecenoic acid (DEOA) and 7-hydroxy-12∶17, 13∶17-diepoxy-9(Z)-octadecenoic acid (hDEOA), by Clavibacter sp. ALA2 was investigated. When cultivated with linoleic acid as a substrate, the strain produced 12,13,17-trihydroxy-9(Z)-octadecenoic acid (THOA), DEOA, and hDEOA as well as other FA. To clarify the synthetic route to these bicyclic FA, the strain was cultivated with purified THOA as a starting substrate. THOA was consumed almost completely by the strain with sequential generation of DEOA and hDEOA. Moreover, the strain produced hDEOA when cultivated with purified DEOA. Therefore, it was confirmed that THOA was a precursor of these bicyclic FA and that hDEOA was generated from DEOA. Based on our previously reported result that linoleic acid is first converted to 12,13-dihydroxy-9(Z)-octadecenoic acid (DHOA) and the present results, the overall biosynthetic pathway for the diepoxy bicyclic FA from linoleic acid was postulated as: linoleic acid→DHOA→THOA→DEOA→hDEOA.     

2，3，7—三羟基—9[（取代基）偶氮]苯荧不酮试剂的合成及其在分析中的应用

对新型2,3,7－三峡基－9[（取代基）偶氮]苯基荧光酮类试剂的合成及影响该类试剂光度性质的因素进行了讨论,并对其在光度分析中的应用进行了评论。附参考文献38篇。     

采用苯基荧光酮测定野蒜和食蒜中锗的含量

以2，3，7-三羟基-9-（2-羟基-5-对甲苯偶氮）苯基荧光酮为显色剂，测定了野蒜和食蒜中锗的含量，加标回收率在91．04％～102．83％，且该方法灵敏度和选择较高。     

有机/无机纳米复合相变储能材料的制备

利用十六烷基三甲基溴化铵（CTAB）嵌入到具有层状结构的膨润土层间,使膨润土层间得到改必,通过交换反应,使三羟甲基丙烷和新戊二醇嵌入膨润土层间而制得有机／无机纳米复合相变储能材料,利用X射线衍射（XRD）和差示扫描量热法（DSC）对制得有机／无机纳米复合相变储能材料进行了表征。     

Liquid phase oxidation of 3,4-dihydroxybenzoic acid and the effect of the products on trihydroxy aluminium precipitation yields

Organic compounds are known to interfere with the precipitation of trihydroxy aluminium (gibbsite) in the Bayer process. Studies have been carried out of the effect of 3,4-dihydroxybenzoic acid on precipitation and of the beneficial effect that can be achieved by oxidising the acid. Measurements of precipitate yields both in the presence of the acid and of products obtained by oxidising the acid were made. Oxidation in the presence of various metal ions was also examined. The yield of precipitate was found to decrease in the order Cu²⁺ (1·9 mM) > Fe³⁺ (2·2 mM) > blank (no added organics) > Mn⁴⁺ (44·3 and 2·3 mM) > Mn²⁺ (2·3 mM) > Mn²⁺ (44·3 mM) ≈ uncatalyset oxidation > Fe³⁺ (43·5 mM) > Cu²⁺ (38·2 mM) > untreated sample. This relative ordering was generally unaffected by reaction temperature or oxygen partial pressure. Soluble manganese salts were formed by partial dissolution of MnO₂ in the alkaline solutions. These salts were required for oxidation of the 3,4-dihydroxybenzoic acid to products which, collectively, did not poison the trihydroxy aluminium precipitation process.     

新显色剂2,3,7-三羟基-9-(2,4-二羟基)苯基荧光酮的合成及与金属离子显色反应的研究

以对苯二酚，2，4－二羟基苯甲醛为基本原料，报道了新显色剂2，3，7－三羟基－9－（2，4－二羟基）苯基荧光酮（DHPF）的合成方法。通过对试剂进行红外光谱、紫外光谱、元素分析确证了试剂的结构。采用分光光度法测定了试剂在水溶液中的离解常数。在表面活性剂存在下研究了试剂与一些高价金属离子的显色反应特性。     

A novel compound, 12,13,17-trihydroxy-9(Z)-Octadecenoic acid,from linoleic acid by a new microbial isolateClavibacter sp. ALA2

A novel compound, 12,13,17-trihydroxy-9(Z)-octadecenoic acid (THOA), was produced from linoleic acid by microbial transformation at 25% yield. The newly isolated microbial strain that catalyzed this transformation was identified asClavibacter sp. ALA2. The product was purified by high-pressure liquid chromatography, and its structure was determined by¹H and¹³C nuclear magnetic resonance, Fourier transform infrared, and mass spectroscopy. Maximum production of THOA was reached after 85 h of reaction. THOA was not further metabolized by strain ALA2. This is the first report on 12,13,17-trihydroxy unsaturated fatty acid and its production by microbial transformation.     

小波变换4,5-二溴羟基苯基荧光酮光度法同时测定钨和钼

痕量钨、钼在混合表面活性剂（ＣＴＭＡＢ＋Ｔｗｅｅｎ－６０）存在下,与４,５－二溴羟基苯基荧光酮发生灵敏的显色反应,所形成的胶束配合物的吸收峰严重重叠。应用小波变换同时测定了混合样中的两组份。     

Separation and quantitation of hydroxy and epoxy fatty acid by high-performance liquid chromatography with an evaporative light-scattering detector

A new high-performance liquid chromatography technique with an evaporative light-scattering detector (ELSD) has been developed for the separation and quantitative analysis of hydroxy and epoxy fatty acids. This method employs a gradual binary gradient (hexane/isopropanol) and ELSD detection. The minimum limit of detection is about 1 μg and ratio of mass to signal is essentially linear in the range of 10 to 200 μg. This high-performance liquid chromatography (HPLC) technique is able to separate various positional isomers of mono-hydroxy and dihydroxy fatty acids and can also discriminate between monohydroxy, epoxy, epoxyhydroxy, dihydroxy and trihydroxy fatty acids.