降解1,3-二甲基-2-咪唑烷酮细菌的分离及功能评价

[背景] 1,3-二甲基-2-咪唑烷酮（1,3-Dimethyl-2-Imidazolidinone,DMI）作为一种强极性非质子溶剂,在生产和应用过程的环境中有稳定残留问题,存在安全隐患。[目的] 分离筛选具有降解DMI能力的微生物菌株,为清除环境中残留的DMI提供优良的微生物菌种资源。[方法] 从DMI生产区域土壤采集样品分离DMI抗性微生物,采用形态学及分子生物学鉴定确定其分类地位,并对DMI降解能力进行测定。[结果] 分离到最高能够耐受5%（体积分数） DMI的微生物菌株,形态学及分子生物学鉴定初步表明获得的菌株DT-1和DT-2为贝莱斯芽孢杆菌（Bacillus velezensis）;全细胞及细胞提取液均具有降解DMI的能力;其中菌株DT-1及其细胞提取液对1%（体积分数） DMI的降解率分别达到48%和68%。[结论] 从DMI生产区域土壤中分离到具有DMI降解能力的芽孢杆菌,不但可为DMI污染的微生物治理提供优良微生物资源,而且扩展了人们对芽孢杆菌生物学功能的认识。     

Cholinesterase inhibitory triterpenoids from the bark of Garcinia hombroniana

Abstract

Context: Garcinia hombroniana Pierre, known as manggis hutan in Malaysia is a rich source of xanthones and benzophenones.

Objectives: This study was aimed to isolate and characterize potential cholinesterase inhibitors from the extracts of G. hombroniana bark and investigate their interactions with the enzymes.

Materials and methods: The dichloromethane extract afforded five triterpenoids which were characterized by NMR and mass spectral techniques. Cholinesterase inhibitory assay and molecular docking were performed to get insight of the inhibitory activity and molecular interactions of the compounds. The compounds were also tested for their antioxidant capacity.

Results: The isolated triterpenoids were identified as: 2β-hydroxy-3α-O-caffeoyltaraxar-14-en-28-oic acid (1), taraxerol (2), taraxerone (3), betulin (4) and betulinic acid (5). Compound 1 was the most active dual inhibitor of both AChE and BChE. Compound 1 also showed good antioxidant activities.

Conclusion: Compound 1 had dual and moderate inhibitory activity on AChE and BChE worthy for further investigations.     

产褪黑素绿色木霉工程菌的构建及生理特性分析

【背景】褪黑素(melatonin)是动植物内广泛存在的一种小分子生物胺类物质,在促进生物生长和提高环境耐受性等方面发挥重要作用。木霉(Trichoderma)既是重要的生防菌株也是高效的工业产品生产菌株,能够合成丰富的代谢产物。【目的】针对目前木霉菌株中还未发现褪黑素合成的问题,构建具有褪黑素合成能力的绿色木霉(Trichoderma viride)工程菌,并对其生理特性进行研究。【方法】在绿色木霉Tv-1511中异源表达了来源于人基因组的芳烷基胺N-乙酰转移酶(aralkylamineN-acetyltransferase,AANAT)编码基因hAANAT和乙酰复合胺-O-甲基转移酶(acetylserotonin-O-methyltransferase,ASMT)编码基因hASMT,高效液相色谱法(highperformance liquid chromatography, HPLC)检测了木霉工程菌合成褪黑素的产量,并利用生化方法检测了工程菌的生长、抗逆及对植物的促生抗病能力。【结果】获得了具有褪黑素合成能力的绿色木霉工程菌,此株工程菌具有更好的生长和产孢特性、更强的逆境胁迫耐...     

Enzyme mediated resolution of alcohols

Summary The racemic cis and trans isomers 1a and 1b of 2-(4-methoxybenzyl)-1-cyclohexanol were subjects of an enzyme mediated resolution via esterification in organic solvents, in which the chiral esters 2a and 2b of the corresponding alcohols 4a and 4b, and the chiral alcohols 3a and 3b were obtained. The chemical yield and enantioselectivity of this enzymatic reaction have been found to depend mainly on (a) the structure of the substrate (cis or trans), (b) temperature, (c) the nature of the enzyme selected, and (d) the nature of the solvent.     

Synthesis of 3-fluoro-6-S-(2-S-pyridyl) nucleosides as potential lead cytostatic agents

The 3-deoxy-3-fluoro-6-S-(2-S-pyridyl)-6-thio-β-d-glucopyranosyl nucleoside analogs 7 were prepared via two facile synthetic routes. Their precursors, 3-fluoro-6-thio-glucopyranosyl nucleosides 5a-e, were obtained by the sequence of deacetylation of 3-deoxy-3-fluoro-β-d-glucopyranosyl nucleosides 2a-e, selective tosylation of the primary OH of 3 and finally treatment with potassium thioacetate. The desired thiolpyridine protected analogs 7a-c,f,g were obtained by the sequence of deacetylation of 5a-c followed by thiopyridinylation and/or condensation of the corresponding heterocyclic bases with the newly synthesized peracetylated 6-S-(2-S-pyridyl) sugar precursor 13, which was obtained via a novel synthetic route from glycosyl donor 12. None of the compounds 6 and 7 showed antiviral activity, but the 5-fluorouracil derivative 7c and particularly the uracil derivative 7b were endowed with an interesting and selective cytostatic action against a variety of murine and human tumor cell cultures.     

Micropropagation of selected somaclones ofBegonia andSaintpaulia

Begonia x elatior plantlets which regenerated from leaf disk callus showed variations in plant morphology, number of flowers per plant, and flower size. Variations in flowering period, number of flowers per plant, and flower morphology were observed in Saintpaulia ionantha L. plants directly regenerated from leaf disk explants. The cytokinins, benzylaminopurine and zeatin, tested in the culture medium did not affect the basic plant characteristics including flower colour which remained stable in both species. Micropropagation of selected somaclones having the desirable trait of high number of flowers per plant was stable in the MV2 and MV3 generations.     

兰州唐古特白刺根际微生物分离鉴定

【目的】从兰州唐古特白刺根际分离得到对植物有潜在促生效果的功能微生物，为研发相关菌种制剂的研究奠定基础。【方法】通过平板划线法从其根际分离纯化出6株细菌，并对菌株进行形态特征观察、革兰氏染色等一系列生理生化试验。用藜麦检测各菌株的促生功能，并对具有优良促生作用的1个菌株16S rRNA基因进行分子鉴定及基因草图绘制。【结果】根据生化鉴定结果，6株细菌分别属于不动杆菌属(Acinetobacter)、土壤杆菌属(Agrobacterium)、类芽孢杆菌属(Paenibacillus)、芽孢杆菌属(Bacillus)、鞘氨醇单胞菌属(Sphingomonas)和假单胞菌属(Pseudomonas)。其中，16S rRNA基因鉴定BC4属于肠杆菌属(Enterobacter)，具有较好的促生效果。【结论】BC4具有较好的促生效果，为兰州唐古特白刺菌种资源的开发和利用提供了一定的理论依据。     

Synthesis of novel sulfonamides under mild conditions with effective inhibitory activity against the carbonic anhydrase isoforms I and II

Novel sulfonamide derivatives 6a–i, as new carbonic anhydrase inhibitors which candidate for glaucoma treatment, were synthesized from the reactions of 4-amino-N-(4-sulfamoylphenyl) benzamide 4 and sulfonyl chloride derivatives 5a–i with high yield (71–90%). The structures of these compounds were confirmed by using spectral analysis (FT-IR, ¹H NMR, ¹³C NMR, LC/MS and HRMS). The inhibition effects of 6a–i on the hydratase and esterase activities of human carbonic anhydrase isoenzymes, hCA I and II, which were purified from human erythrocytes with Sepharose®4B-l-tyrosine-p-aminobenzene sulfonamide affinity chromatography, were studied as in vitro, and IC₅₀ and K_i values were determined. The results show that newly synthesized compounds have quite powerful inhibitory properties.     

Evidence for declines in populations of grassland-associated birds in marginal upland areas of Britain

Capsule We report large declines among summer populations between 1968–80 and 2000.

Aim To assess changes in the status of breeding populations of birds in pastoral uplands.

Methods Volunteer observers revisited 13 areas of marginal upland in Britain where Common Birds Census data were collected during 1968–80. This allowed the status of 35 bird species to be examined over about 20 years and to make a comparison between grassland-based and woodland-based species.

Results For 12 species the decline in abundance was significant, particularly among passerines, such as Skylark Alauda arvensis, Wheatear Oenanthe oenanthe, Whinchat Saxicola rubetra, Yellow Wagtail Motacilla flava and Yellowhammer Emberiza citrinella, each of which declined by over 80%. Redshank Tringa totanus, Yellow Wagtail, Dipper Cinclus cinclus, Whinchat, Wheatear, Ring Ouzel Turdus torquatus and Yellowhammer were found on less than half the number of plots on which they were originally recorded. Most declining species were associated with grassland for nesting and foraging, compared to those species that increased (Wood Pigeon Columba palumbus, Pied Wagtail Motacilla alba, Carrion Crow Corvus corone, Jackdaw C. monedula and Goldfinch Carduelis carduelis) that were less specialized in their habitat requirements. Woodland or woodland edge species showed no significant change in status, suggesting that population declines among grassland species were not due to lower observer effort between recording periods.

Conclusion Long-term changes to grassland ecosystems in marginal upland areas of Britain may have influenced the status of bird populations.     

Design,synthesis, spectral analysis and in vitro microbiological evaluation of 2-phenyl-3-(4,6-diarylpyrimidin-2-yl)thiazolidin-4-ones

A series of novel 2-phenyl-3-(4,6-diarylpyrimidin-2-yl)thiazolidin-4-ones 23-33 were synthesized, and studied for their in vitro antibacterial and antifungal activities against clinically isolated strains. Generally compounds possessing electron donating groups showed good antibacterial activity. Compound 31, which contain both electron withdrawing chloro and electron donating methyl groups showed potent activity against all the tested Gram positive and Gram negative bacterial strains whereas compounds 32 and 33 which contain electron donating methoxy functional group at the para position of the phenyl ring attached to pyrimidine ring showed promising activity against S.aureus, S.typhii and E.coli. Compounds 32 and 33, both containing electron withdrawing groups (-Cl, -F) showed excellent activities against all the tested A. flavus, Mucor, Rhizopus and M.gypsuem fungal strains. while against Mucor, compound 27 which contains an electron donating methyl group at the para position of the phenyl ring attached to pyrimidine ring showed promising activity. Also compound 31, which contains both electron withdrawing chloro and electron donating methyl groups showed potent activity against A. flavus and Rhizopus.     

Comparison of Soybean Tissue Extracted with Different Solvents

The enantioselective hydrolysis of (R,S)-3-acetoxymethyl-7,8-difluoro-2,3-dihydro-4H-[1,4]benzoxazine (I) with enzymes was investigated. Optically active I and its hydrolyzate, 7,8-difluoro-2,3-dihydro-3-hydroxymethyl-4H-[1,4]benzoxazine (II), are the intermediates for preparing optically active ofloxacins, whose racemate is known to be an excellent antibacterial agent. Lipoprotein lipase from Pseudomonas fluorescens (LPL Amano 3) was found to predominantly hydrolyze (S)-I, giving (R)-I in 54% e.e. and (R)-II in 44% e.e. On the other hand, lipase from Candida cylindracea was found to predominantly hydrolyze (R)-I, giving (S)-I in 24% e.e. and (S)-II in 20% e.e. Since, the optical purities of I and II thus obtained were not particularly high, these optically active I and II were converted into 3-acetoxymethyl-7,8-difluoro-2,3-dihydro-4-(3,5-dinitrobenzoyl)-4H-[1,4]benzoxazine (IV). After recrystallizing IV from ethyl acetate-hexane, (S)- and (R)-II were obtained with high enantiomeric excess by removing the crystallized racemic IV and subsequently hydrolyzing the resulting optically active IV with alkali. The reduction of II afforded 7,8-difluoro-2,3-dihydro-3-methyl-4H-[1,4]benzoxazine (III), for which the optical purity was estimated to be >96%e.e. by HPLC analysis. (R)- and (S)-ofloxacin were prepared from (R)- and (S)-III with retention of their configuration.     

Effects of Trialkyltin Chlorides on Escherichia coli Spheroplasts

Valsa ceratosperma, which is the pathogenic fungus of apple canker, was grown in a synthetic medium. The neutral extract from the culture filtrate was chromatographed on a silica gel column to give five isocoumarins. Their structures were determined by MS, UV, IR, ¹H and ¹³C NMR, and CD spectra. Three of them were known compounds; ( ? )-5-methylmellein (1), ( ? )-5-carboxylmellein (2) and ( ? )-5-hydroxylmethylmellein (3). Since the absolute configurations at C-3 in 2 and 3 were not known until now, both were determined to be R by chemical correlations. The two were new compounds; ( + )-(3R,4S)-trans-4-hydroxy-5-methylmellein (4) and ( ? )-(3R,4R)-cis-4-hydroxy-5-methylmellein (5). All the five compounds showed phytotoxicity in a bioassay using detached apple shoots and lettuce seedlings.     

Synthesis of the Fluoromethyl Derivatives of Carbocyclic Oxetanocin A

Abstract

Treatment of the 2,3-di-O-benzoate 1 with sodium boronhydride mainly afforded the 3-O-benzoate 2 accompanied with isomers 3a,b and fully deprotected product 4. Compound 2 was converted to 5, from which 8 was obtained. The 1-cyclobutanols 8 and 5 were successfully condensed with 6-chloropurine by Mitsunobu reaction to give 9 and 11, respectively. After partial deprotection, the cyclobutyl nucleosides 10 and 15 were subjected to fluorination using DAST to afford the fluoromethyl analogs 12 and 16 from which target compounds 14 and 17 were obtained in good yields, respectively.

     

Biotransformation of (20S)-20-hydroxymethylpregna-1,4-dien-3-one by four filamentous fungi

Microbial transformation of (20S)-20-hydroxymethylpregna-1,4-dien-3-one (1) by four filamentous fungi, Cunninghamella elegans, Macrophomina phaseolina, Rhizopus stolonifer, and Gibberella fujikuroi, afforded nine new, and two known metabolites 2–12. The structures of these metabolites were characterized through detailed spectroscopic analysis. These metabolites were obtained as a result of biohydroxylation of 1 at C-6β, -7β, -11α, -14α, -15β, -16β, and -17α positions, except metabolite 2 which contain an O-acetyl group at C-22. These fungal strains demonstrated to be efficient biocatalysts for 11α-hydroxylation. Compound 1, and its metabolites were evaluated for the first time for their cytotoxicity against the HeLa cancer cell lines, and some interesting results were obtained.     

Inhibition of Real-Time PCR in DNA Extracts from Aquifer Sediment

Variation in inhibition of real-time PCR was investigated with DNA extracts from 50 aquifer sediment core samples of 5 cm length collected through a 2.5 meter vertical profile across a landfill leachate plume. The inhibition was quantified using an internal control of the green fluorescent protein ( gfp ) gene, which was spiked into the real-time PCR reactions. The inhibition was investigated at two gfp gene concentrations: at 1.7 · 10 ⁷ gfp gene copies/g sediment (5.1 · 10 ⁴ gfp gene copies/PCR reaction) and at 1.7 · 10 ⁵ gfp gene copies/g sediment (5.1 · 10 ² gfp gene copies/PCR reaction). Despite the low TOC content of the sediment (average 0.4 mg C/g dw) the average real-time PCR response was partially inhibited, compared to a reference (pure water), at both high and low gfp concentrations. The relative amplification (reference = 1) was 0.85 ± 0.20 (high) and 0.66 ± 0.23 (low), showing significantly (P < 0.05) stronger inhibition at the lower target gene concentration. The inhibition of the real-time PCR did not show a systematic variation in the vertical profile related to plume position but variations were significant on a small scale of 5–15 cm depth intervals. One of the 50 samples failed to produce a signal with either concentration of the gfp internal control and three other samples inhibited real-time PCR at both high and low gfp concentration. These 4 samples, which were the samples with the highest inhibition, were the only DNA extracts with a visible brown colouration, indicating contents of humic-like substances. Elevated absorbance at 400 nm of these samples also indicated that humic-like substances were responsible for inhibition. However, other factors not associated with either absorbance or TOC may have contributed to the inhibition in less inhibited samples since the variation in real-time PCR response could not be sufficiently explained by absorbance or TOC. The results of this study suggest that an internal control is needed in real-time PCR reactions with DNA from environmental samples due to variation in inhibition to correctly quantify the number of target genes, especially at low target gene concentrations, when dilution of DNA extracts is not practical.     

杭州地区扶桑绵粉蚧危害调查及系统进化分析

【背景】扶桑绵粉蚧是近年来入侵我国的重要检疫性害虫,在我国多个省份均有发生,造成了严重的经济损失。【方法】于2009—2015年对杭州地区扶桑绵粉蚧的发生危害情况进行了实地调查,同时结合mt DNA COI分子标记方法,对扶桑绵粉蚧进行分子鉴定和系统进化分析。【结果】杭州市余杭区、萧山区和临安市3个地区发现扶桑绵粉蚧分布,共调查到寄主植物38科61属68种,以辣椒、茄子、番茄、南瓜、棉花、芝麻、菊花、苦荬菜、大花马齿苋和五色梅受害最严重。系统进化分析表明,杭州地区的扶桑绵粉蚧未发生明显的遗传分化,与我国其他地区扶桑绵粉蚧mt DNA COI基因相似度为99.4%~100%。【结论与意义】本研究为进一步研究扶桑绵粉蚧的遗传进化、可能的侵入途径以及科学防控提供了理论基础。     

武夷菌素高产基因工程菌株Streptomyces albulus OoWysR活性成分的分离鉴定

【背景】武夷菌素高产基因工程菌株Streptomyce albulus OoWysR具有明显的抑菌效果。【目的】明确S.albulus OoWysR的活性成分。【方法】采用柱层析法,利用大孔吸附树脂、离子交换树脂和高效液相色谱等对S.albulus OoWysR的活性成分进行分离纯化,经高分辨率电喷雾电离质谱(high-resolution electrospray ionization mass spectrometry,HR-ESI-MS)和核磁共振(nuclear magnetic resonance,NMR)等波谱技术对化合物化学结构进行鉴定,并通过生长速率法测定化合物的生物活性。【结果】从S.albulus OoWysR中分离鉴定出4个化合物,分别为对羟基苯甲酸(1)、吡咯-2-羧酸(2)、对羟基苯乙醇(3)和云南霉素(4)。化合物1对玉米弯孢病菌、番茄叶霉病菌、玉米小斑病菌和烟草赤星病菌具有一定的抑制作用;化合物2对番茄灰霉病菌、大豆菌核病菌、苹果腐烂病菌、玉米小斑病菌、小麦赤霉病菌、稻瘟病菌和烟草赤星病菌具有一定的抑制作用;化合物3对番茄灰霉病菌、苹果轮纹病菌、玉米小斑病...     

Preparation of Optically Active 2-Aminobutanoic Acid via Optical Resolution by Replacing Crystallization

An attempt was made to use a simple procedure to obtain (R)- and (S)-2-aminobutanoic acids [(R)- and (S)-1] which are non-proteinogenic α-amino acids and are useful as chiral reagents in asymmetric syntheses. Compound (RS)-1 p-toluenesulfonate [(RS)-2], which is known to exist as a conglomerate, was optically resolved by replacing crystallization with (R)- and (S)-methionine p-toluenesulfonate [(R)- and (S)-3] as optically active co-solutes. When (S)-3 was employed as the co-solute, (R)-2 was preferentially crystallized from a supersaturated solution of (RS)-2 in 1-propanol, as was (S)-2 in the presence of (R)-3. (R)- and (S)-2 recrystallized from 1-propanol were treated with triethylamine in methanol to give (R)- and (S)-1 in optically pure forms.     

一株耐盐甲基杆菌Methylobacterium sp.W-1的分离及促生潜能研究

[背景] 多种甲基杆菌属细菌对寄主植物有促生作用,其分布区域较广。筛选具有耐盐与促生特性的甲基杆菌属菌株可为微生物菌肥的开发提供依据。[目的] 从新疆乌尔禾地区盐渍土壤中筛选耐盐促生菌,对其培养基成分进行优化及促生能力进行研究,为微生物菌肥的开发提供依据。[方法] 采用阿须贝无氮培养基筛选耐盐菌株,对菌株进行基因序列分析及生理生化测定,采用平板试验法初步研究该菌对拟南芥的生长影响。[结果] 筛选出中度耐盐菌株W-1,经鉴定为甲基杆菌属（Methylobacteriumsp.）。菌株生长最佳无机盐为NaCl,最适浓度为1%–3%,最高耐受浓度达7%。最佳氮源为酸水解酪蛋白,产生长素最高达33.53 mg/L。溶磷能力达28.71 mg/L。菌株W-1接种拟南芥幼苗后叶绿素a和叶绿素b含量均高于对照组,同时对其根系发育有显著的促进作用。[结论] 菌株W-1促生性能显著,可为生物肥料制备提供菌种资源。     

A Convenient Synthesis of Acyclic Adenosines with an Unsaturated Side Chain by Modification of 9-(2,3-O-Isopropylidene-D-Ribityl)Adenine

Abstract

In expectation of discovering their antiviral activity, acyclic adenosine derivatives 7, 11, 12, and 16 were designed as analogs of neplanocin A (NPA) and L-eritadenine which are strong inhibitors of S-adenosyl-L-homocysteine hydrolase. The 1′,5′-seco-analog of 4′-deoxymethyl-NPA (DHCA) 7 was synthesized by dideoxygenation of 9-(2,3-O-isopropylidene-D-ribityl)adenine (2). Acyclic DHCA analogs 11 and 16 were obtained by Wittig reaction of the aldehyde 3 with Ph₃P=CHCO₂Et and Ph₃P=CHCN, respectively. Hydrolysis of the ester 11 afforded a vinylog of L-eritadenine 12. The synthesized acyclic nucleosides 7, 10, and 11 were evaluated for antiviral activity, however, none of them showed any significant antiviral activity.