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1.
金色补血草化学成分的研究   总被引:2,自引:0,他引:2  
从金色补血草[Limonium aureum(L.)Hill ex Kuntze]中首次分得5种结晶,经鉴定分别为:(Ⅰ)高北美圣草素、(Ⅱ)柚皮素、(Ⅲ)北美圣草素、(Ⅳ)杨梅树皮素-з-O-β-D-葡萄糖甙、(Ⅴ)杨梅树皮素-з-O-β-D-半乳糖甙。  相似文献   

2.
杨梅树皮黄酮的提取及体外抗氧化研究   总被引:1,自引:0,他引:1  
采用乙醇热回流提取法对杨梅树皮中总黄酮进行提取,通过正交试验确定了杨梅树皮总黄酮乙醇热回流提取法的最佳工艺条件:以28目的杨梅树皮粉为原料,料液比为1∶60,用60%的乙醇溶液在60℃的水浴中提取2.5h,提取率达6.86%。利用清除DPPH自由基的能力和还原力作为指标测定了杨梅树皮总黄酮的抗氧化活性。结果表明,杨梅树皮黄酮有较强的抗氧化能力。  相似文献   

3.
中药土槿皮是松科(Pinaceae)植物金钱松(Pseudolarix Kaempferi Gor-don)的干燥树皮及根皮。过去对土槿皮原药抗真菌作用已有不少研究,其化学成份也有人进行了分析,并从原药中提取了土槿皮乙酸,报告了它的分子式,为C_(23)H_(28)O_8,展开式为C_(15)H_(12)O(C=C—COOH)(COOCH_3)(OCO-CH_3)(C=O),进一步测定和解析了土槿皮乙酸的高分辨质谱,提出土槿皮乙酸可  相似文献   

4.
竹叶花椒化学成分研究   总被引:5,自引:0,他引:5  
从竹叶花椒(Zanlhoxylum armatum DC.)树皮中分离到13种化合物,经波谱(UV,IR,NMR,MS)分析及理化常数的对照,鉴定出其中的9种,它们是:β-白檀酮(β-amyrone)(Ⅱ),β-香木脂醇(β-amyrin)(Ⅱ),L-细辛素(L-asarinin)(Ⅳ),L-芝麻素(L-sesamin)(V).L-竹叶椒脂素(L-planinin)(Ⅵ),β-胡萝卜甙(β-daucosterol)(X),香草酸(Vanillic acid)(Ⅺ),β-谷甾醇(β-sitosterol)(Ⅻ),和一长链混合脂肪酸(二十四酸为主)(A mixed long-chain fatty acid)(Main in C_(24)H_(48)O_2)(Ⅻ)。其中的晶Ⅱ和Ⅺ为首次从该属植物分离到,晶Ⅱ,Ⅴ,Ⅹ,Ⅺ和Ⅻ为首次从本植物分离到。 其余4种化合物正在鉴定中。  相似文献   

5.
从苦木的本质部乙醇提取物中分离到一种新的生物碱(Ⅰ),呈金黄色短小针晶,m、326~8℃分子式C_(15)H_(10)N_2O_3,经红外、核磁和质谱数据确定其结构为1-羟基-3-甲基铁司-2,6-二酮。  相似文献   

6.
豚草的药用     
豚草(Ambrosia artemisiifolia)和三裂叶豚草(Afrifida)是世界公害性杂草,应大力防治,但在灭草的同时,也应研究利用。据国外报导:(1)沿海豚草(A maxitima)中的豚草素(C_(15)H_(18)O_3)对淋巴细胞白血病P388有抑制作用,在35、22、14及9.6mg/kg剂量时,其T/C值分别为180、158、130和132%,表明给药组的白细胞显著高于对照组。另外豚草素对血吸虫宿生小螺的Lc90(90%致死浓度)分别为10.9和8.5ppm。(2)豚草属另一种(A.ambrosioides)内含二氢豚草酸(C_(15)H_(22)O_3)和二氢豚草素(C_(15)H_(20)O_3)其茎叶对人体鼻咽癌(KB)细胞有细胞毒活性,前者ED_(50)(半数有效量)大于100μg/ml;后者为0.32μg/ml。另外,豚草被认为  相似文献   

7.
维西香茶菜的二萜成分   总被引:1,自引:0,他引:1  
维西香茶菜Rabdosia weisiensis C. Y. Wu产云南西北部海拔2600米沟谷中,其化学成分的研究未见报道。从该植物叶的乙醚提取物中,分得两个二萜成分,一为已知成分trichorabdal A(2),一为新成分,命名为维西香茶菜甲素weisiensin A(1)。 维西香茶菜甲素weisiensin A(1),C_(26)H_(36)O_9,mp 298—300℃,其~(13)C NMR谱显示存在三个CH_3,三个CH_2,八个CH,三个四取代碳,三个Ac,二个烯碳和一个羰基  相似文献   

8.
问题解答     
问:高中课本第9页中说:“糖类的分子式可以用通式C_n(H_2O)_m来表示(n和m可以相同,也可以不同)”请将n和m相同与不同的举例说明。答:糖类化合物是指具有多羟基醛或多羟基酮结构的一大类化合物。糖由碳、氢、氧三种元素组成。其中氢和氧的比例为2:1,就象氢和氧在水分子中的比例一样。所以糖的通式可写成C_n(H_2O)_m,并因此被称为碳水化合物。如赤藓糖的分子式为C_4H_8O_4,可写成C_4(H_2O)_4;核糖的分子式为C_5H_(10)O_5,可写成C_5(H_2O)_5;葡萄糖的分子式为C_6H_(12)O_6,可写成C_6(H_2O)_6等。  相似文献   

9.
有些植物生理学教科书和参考书中常将呼吸作用的反应方程式写成:C_6H_(12)O_6+6O_2→6CO_2+6H_2O+能量(686千卡),或写成:C_6H_(12)O_6+6O_2→6CO_2+6H_2O △G~0'=-686千卡。这两条写法都不够确切,因为式中前面指的都是1分子葡萄糖参加反应,而后面产生的自由能为686千卡,前后不相符。因为每摩尔葡萄糖(1摩尔葡萄糖分子含有6.023×10~(23)个葡萄糖分子)完全氧化时产生的自由能为686千卡,所以方程式应写成C_6H_(12)O_6+6O_2→6CO_2+6H_2O+能量(686千卡/摩尔);或C_6H_(12)O_6+6O_2→6CO_2+6H_2O △G~0'=-686千卡/摩尔。教师在教学中应提醒学生,切莫误解。  相似文献   

10.
从丽江紫堇(Corydalis delavayi Franch.)中得到一个微量生物碱,在甲醇中重结晶得到无色针状结晶,mp 210—212℃;MS m/e:423(M~+),405,366(基峰),350,202,189,58,43。无素分析C_(24)H_(25)O_6N计算值(%)C 68.08,H 5.91,N3.31;实测值(%)C 67.69,H 5.79,N 3.43。UVλ_(max)~(MeOH)nm(logε):237(3.99),289(2.92)。IRν_(max)~(KBr)cm~(-1):3450,2870,1712,1620,1500,1483,1460,1360,  相似文献   

11.
T Zhao  M P Doyle    R E Besser 《Applied microbiology》1993,59(8):2526-2530
A strain of enterohemorrhagic Escherichia coli serotype O157:H7 isolated from a patient in an apple cider-related outbreak was used to study the fate of E. coli O157:H7 in six different lots of unpasteurized apple cider. In addition, the efficacy of two preservatives, 0.1% sodium benzoate and 0.1% potassium sorbate, used separately and in combination was evaluated for antimicrobial effects on the bacterium. Studies were done at 8 or 25 degrees C with ciders having pH values of 3.6 to 4.0. The results revealed that E. coli O157:H7 populations increased slightly (ca. 1 log10 CFU/ml) and then remained stable for approximately 12 days in lots inoculated with an initial population of 10(5) E. coli O157:H7 organisms per ml and held at 8 degrees C. The bacterium survived from 10 to 31 days or 2 to 3 days at 8 or 25 degrees C, respectively, depending on the lot. Potassium sorbate had minimal effect on E. coli O157:H7 populations, with survivors detected for 15 to 20 days or 1 to 3 days at 8 or 25 degrees C, respectively. In contrast, survivors in cider containing sodium benzoate were detected for only 2 to 10 days or less than 1 to 2 days at 8 or 25 degrees C, respectively. The highest rates of inactivation occurred in the presence of a combination of 0.1% sodium benzoate and 0.1% potassium sorbate. The use of 0.1% sodium benzoate, an approved preservative used by some cider processors, will substantially increase the safety of apple cider in terms of E. coli O157:H7, in addition to suppressing the growth of yeasts and molds.  相似文献   

12.
Samples of staphylococcal nuclease H124L (cloned protein overproduced in Escherichia coli whose sequence is identical with that of the nuclease isolated from the V8 strain of Staphylococcus aureus) were labeled uniformly with carbon-13 (26% ul 13C), uniformly with nitrogen-15 (95% ul 15N), and specifically by incorporating nitrogen-15-labeled leucine ([98% 15N]Leu) or carbon-13-labeled lysine ([26% ul 13C]Lys), arginine ([26% ul 13C]Arg), or methionine ([26% ul 13C]Met). Solutions of the ternary complexes of these analogues (nuclease H124L-pdTp-Ca2+) at pH 5.1 (H2O) or pH* 5.5 (2H2O) at 45 degrees C were analyzed as appropriate to the labeling pattern by multinuclear two-dimensional (2D) NMR experiments at spectrometer fields of 14.09 and 11.74 T: 1H-13C single-bond correlation (1H[13C]SBC); 1H-13C single-bond correlation with NOE relay (1H[13C]SBC-NOE); 1H-13C single-bond correlation with Hartmann-Hahn relay (1H-[13C]SBC-HH); 1H-13C multiple-bond correlation (1H[13C]MBC); 1H-15N single-bond correlation (1H-[15N]SBC); 1H-15N single-bond correlation with NOE relay (1H[15N]SBC-NOE). The results have assisted in spin system assignments and in identification of secondary structural elements. Nuclear Overhauser enhancements (NOE's) characteristic of antiparallel beta-sheet (d alpha alpha NOE's) were observed in the 1H [13C]-SBC-NOE spectrum of the nuclease ternary complex labeled uniformly with 13C. NOE's characteristic of alpha-helix (dNN NOE's) were observed in the 1H[15N]SBC-NOE spectrum of the complex prepared from protein labeled uniformly with 15N. The assignments obtained from these multinuclear NMR studies have confirmed and extended assignments based on 1H[1H] 2D NMR experiments [Wang, J., LeMaster, D. M., & Markley, J. L. (1990) Biochemistry (preceding paper in this issue)].  相似文献   

13.
Haec species proxima H.changhuaensi Y. H.Zhang,a qua racemis longioribtus,laxioribus,siliculis longe obovoideis,stylis longlogioribus sub fructu c. 2 mm longis,seminibus superificie tuberculis minoribus dense munitis recedit.  相似文献   

14.
The bacterial transformation of abietic acid   总被引:3,自引:0,他引:3       下载免费PDF全文
An Alcaligenes species, which was isolated from soil, can utilize abietic acid as its sole carbon source. During growth, the bacterium transforms abietic acid into 5alpha-hydroxyabietic acid (I, R=OH), a product considered to be 7beta-hydroxy-13-isopropyl-8xi-podocarp-13-en-15-oic acid (II, R=H) and a compound, C(20)H(28)O(3), which is believed to be an epoxy-gamma-lactone.  相似文献   

15.
The synthesis, characterization and comparative biological study of a series of antibacterial copper complexes with heterocyclic sulfonamides were reported. Two kinds of complexes were obtained with the stoichiometries [Cu(L)2] . H2O and [Cu(L)2(H2O)4] . nH2O. They were characterized by infrared and electronic spectroscopies and the crystal structure of [Cu(sulfisoxazole)2(H2O)4] . 2H2O was determined by single crystal X-ray diffraction. It crystallized in the C2/c with Z = 8 monoclinic space group C2/c with Z = 8. The Cu(II) is in a slightly tetragonal distorted octahedron formed by four oxygen atoms from water molecules and two nitrogen atoms from two isoxazole rings. The antimicrobial activity was evaluated for all the synthesized complexes and ligands using the agar dilution test. The results showed that the complexes with five-membered heterocyclic rings were more active than the free sulfonamides while the pyrimidine, pyridine and pyridazine complexes had similar or less activity than the free ligands. In order to find an explanation for this behavior lipophilicity and superoxide dismutase-like activity were tested, showing that the [Cu(sulfamethoxazol)2(H2O)4] . 3H2O presented the highest antimicrobial potency and a superoxide dismutase-like activity comparable with pharmacological active compounds.  相似文献   

16.
Na(2)[PtCl(6)] was found to react with (9-MeAH)Cl(.)H(2)O (2) (9-MeA=9-methyladenine) in aqueous solution yielding (9-MeAH)(2)[PtCl(6)](.)2H(2)O (3). The same compound was obtained from hexachloroplatinic acid and 9-methyladenine. Performing this reaction at 60 degrees C, complex formation took place yielding the 9-methyladeninium complex [PtCl(5)(9-MeAH)](.)2H(2)O (4a). An analogous complex, [PtCl(5)(9-MeAH)](.)1/2(18C6)(.)H(2)O (4b, 18C6=crown ether 18-crown-6), was formed in the reaction of aquapentachloroplatinic acid (H(3)O)[PtCl(5)(H(2)O)](.)2(18C6)(.)6H(2)O (1) with 9-methyladenine in 1:1 ratio. All complexes were isolated in moderate to good yields as yellow powder (4b) and crystals (3, 4a), respectively. They were fully characterized by microanalysis, IR and NMR ((1)H, (13)C, (195)Pt) spectroscopies, and in part (2, 3, 4a) also by single-crystal X-ray diffraction analysis. Molecular structure of complex 4a exhibited that the 9-methyladeninium ligand is N1 protonated and coordinated through N7 to platinum(IV).  相似文献   

17.
Territrems, tremorgenic mycotoxins of Aspergillus terreus.   总被引:3,自引:0,他引:3  
The tremorgenic mycotoxins isolated from Aspergillus terreus were given the trivial names territrem A and B instead of their previous designations of C1 and C2 respectively. High-resolution mass spectral data suggested the molecular formula of territrem A to be C28H30O9 and that of territrem B,C29H34O9. They were partially characterized by ultraviolet, infrared, proton magnetic resonance, and mass spectroscopy. The spectroscopic evidence indicated that their chemical structures were very similar. The procedures of purification were also revised for the complete separation of these two chemically related compounds.  相似文献   

18.
Two mononuclear copper(II) complexes, [Cu(C(15)H(16)NO(2))(2)] (1) and [Cu(C(6)H(9)N(2)O(4))(2)·3H(2)O] (2·3H(2)O), were synthesised and structurally characterised by single-crystal X-ray analysis. The copper(II) atom adopts a square-planar environment in complex 1, while the geometry in 2·3H(2)O could be described as the distorted square pyramidal. Complexes 1 and 2·3H(2)O were evaluated for their inhibitory activities against Helicobacter pylori (H. pylori) urease in vitro. They both were found to have strong inhibitory activities against H. pylori urease comparable to that of acetohydroxamic acid (AHA). A docking simulation was performed to position 2 into the H. pylori urease active site to determine the probable binding conformation.  相似文献   

19.
Territrems, tremorgenic mycotoxins of Aspergillus terreus.   总被引:4,自引:3,他引:1       下载免费PDF全文
The tremorgenic mycotoxins isolated from Aspergillus terreus were given the trivial names territrem A and B instead of their previous designations of C1 and C2 respectively. High-resolution mass spectral data suggested the molecular formula of territrem A to be C28H30O9 and that of territrem B,C29H34O9. They were partially characterized by ultraviolet, infrared, proton magnetic resonance, and mass spectroscopy. The spectroscopic evidence indicated that their chemical structures were very similar. The procedures of purification were also revised for the complete separation of these two chemically related compounds.  相似文献   

20.
A "neutral" polymer of glucose, galactose, and 2-acetamido-2-deoxyglucose (molar ratios 1:1:2) has been isolated from the lipopolysaccharide of Serratia marcescens strain C.D.C. 1783-57 (O14:H9). Degradative and spectroscopic studies established that the polysaccharide has a branched tetrasaccharide repeating-unit of the structure shown. The polymer was absent from other strains of serogroup O14 studied, but a polymer differing only in the configuration of the glucose residue has previously been isolated from a strain of S. marcescens O8. The polymer from strain C.D.C. 1783-57 also shares structural features with the Escherichia coli O18 antigen, which is known to be serologically related to the S. marcescens O8 antigen. (Formula: see text).  相似文献   

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