大豆异黄酮的LC-MS分析

大豆异黄酮是从大豆中提取的1种天然异黄酮类混合物,具有抗氧化及抗癌作用,长期服用不仅能降低胆固醇,减少心脏病的发生,而且可以降低癌症的发病率[1,2].此外,大豆异黄酮还具有内分泌调节功能,用于缓解妇女更年期症状.随着人们保健意识的加强,大豆异黄酮将成为医药、保健、食物等方面多功能产品.由于其组份多,缺少标准对照物质,定性定量分析该类化合物比较困难.文献报导[3]的方法只分析了其中的几个组份,我们采用LC-MS方法,首次同时分析了大豆异黄酮中的12个成分,并用归一化法测定了各组份的相对含量,为控制该产品的质量提供了可靠的分析手段.     

静态瞬稳注射-化学发光法测定大豆异黄酮

大豆黄酮属于大豆异黄酮的一种,大豆异黄酮是大豆生长过程中形成的次生代谢产物,属于黄酮类化合物,主要以异黄酮糖苷和相应的苷元形式存在。大豆异黄酮具有弱雌激素、抗氧化、抗溶血和抗真菌等活性,能有效地预防和抑制白血病、骨质疏松、胃癌、乳腺癌和前列腺癌等多种疾病的发生。目前,测定大豆异黄酮的方法主要有紫外分光光度法、高效液相色谱法。因大豆异黄酮与杂蛋白的紫外吸收峰较近,用紫外分光光度法测定时背     

大豆素的结构修饰

大豆素是从大豆中分离出的异黄酮类成分,也是中药葛根中的活性成分之一.它具有雌激素样作用,用于治疗骨质疏松症、降低胆固醇等.异戊烯取代的某些黄酮类化合物具有很强的雌激素样作用,且有很强的抗真菌活性及细胞毒作用[1～3],因此,我们以大豆素为先导物与溴代异戊烯在碳酸钾存在下室温进行醚化反应,然后以N,N-二乙基苯胺为溶剂微波加热进行Claisen重排反应,得到几个异戊烯基取代的异黄酮类衍生物,以便进一步研究它们的生物活性.     

三(3,6-二氧杂庚基)胺相转移催化合成Rothindin

具有抗缺氧缺血、雌激素样和抑制癌细胞生长等生理活性[1-2]的异黄酮,主要以糖苷形式存在于自然界.以7-羟基-3′,4′-亚甲二氧基异黄酮(ψ-赝靛素,3)为苷元的异黄酮糖苷Rothindin (1),广泛分布于Rothia indica Linn[3]和Thermopsis alterniflora[4]等植物根茎中,贾世山等[5]也从民间习用药材中间锦鸡儿Caragana intermedia (Leguminosae)根中分离得到.     

大豆乳清废水中异黄酮吸附的影响因素分析

实验研究和理论分析表明：吸附原料液的溶液体系非常复杂，其中大豆异黄酮含量很低，而干扰溶质种类多且含量高，所以在应用大孔树脂时大豆异黄酮的吸附分离中会同时存在多种不利因素．其中的大豆乳清蛋白、大豆低聚糖和大豆皂甙各自由于不同的原因而可能对大豆异黄酮的吸附产生较大的影响．在分析了这些影响因素的基础上，经实验研究所开发的“两级吸附”工艺充分发挥了大豆异黄酮的吸附优势，得到了纯度高于42％的大豆异黄酮产品，树脂吸附的回收率在75％以上．     

双甲基化大豆苷元磺酸锂的合成及晶体结构

以大豆苷元为先导化合物,合成了水溶性异黄酮化合物4’,7-二甲氧基异黄酮磺酸锂．X射线单晶衍射分析表明：标题化合物属于三斜晶系,空间群Pi,晶胞参数为：a=0．7732（2）nm,b=1．874（5）nm,c=1．920（5）nm,α=111．224（4）°,β=90．21（5）°,γ=100．68（4）°Z=2．标题化合物的分子组成为[Li（H2O）4]2（C17H13O4SO3）2·4H2O,其中两种类型的锂离子均被4分子水所配位．[Li（H2O）4]^＋、C17H13O4SO3^-和H2O之间存在多种氢键作用;氢键作用以及阴阳离子之间的静电引力作用共同将标题化合物组装成具有三维网络结构的超分子．     

水溶性双甲基化大豆苷元磺酸钴的合成及其晶体结构

以大豆苷元为先导化合物,合成了水溶性异黄酮衍生物--4′,7-二甲氧基异黄酮磺酸钴{[Co(H_2O)_6](C_(17)H_(13)O_4SO_3)_2·8H_2O(1)},其结构经~1H NMR,IR,元素分析和X-射线单晶衍射表征.1属单斜晶系,空间群P21/c,晶胞参数a=18.697(4)(A),b=7.358(2)(A),c=18.368(4)(A),β=116.223(1)°,Z=2.1的Co(Ⅱ)位于对称中心并被6分子水所配位;[Co(H_2O)_6]~(2+),[C_(17)H_(13)O_4SO_3]~- 和H_2O之间存在多种氢键,形成晶体结构中的亲水区.异黄酮骨架间反平行排列,存在着π┈π堆积作用,构成晶体结构中的疏水区.磺酸根是连接亲水区和疏水区的桥梁.氢键、π┈π堆积以及阴阳离子之间的静电引力作用共同将1组装成具有三维网络结构的超分子.     

大豆异黄酮与人体健康

大豆异黄酮是一种近年来引起营养与医学界广泛关注的物质,它对于人体健康有着重要的作用,可以有效地防治癌症、心血管疾病,抵抗骨质疏松症、妇女更年期综合症等疾病,因而越来越受到人们的重视。本文介绍了大豆异黄酮的结构、对人体健康的影响以及它的利用前景。     

选择性吸附树脂ADS-22制备高含量大豆异黄酮

筛选6种不同性能的吸附树脂,对比了这些树脂对大豆异黄酮的吸附规律.结果表明,以大豆胚为原料,用乙醇提取,经选择性吸附树脂ADS-22的吸附,再用75%的乙醇洗脱,可得到含量达74.37%大豆异黄酮提取物,表明ADS-22树脂对大豆异黄酮有良好的吸附选择性.     

成都生物所发明判断大豆异黄酮糖苷水解的方法

不久前,中科院成都生物所发明的“一种判断大豆异黄酮糖苷是否水解或水解程度的方法”获得国家发明专利授权。大豆异黄酮是大豆等豆科植物生长过程中形成的一类次生代谢产物,具有多种生理功能,它不仅参与调节植物的生长活动,还能对人体发挥有益的生理调节作用。为了得到生物活性高的大豆异黄酮苷元,在工业上大多以大豆豆饼或豆粕为底物,采用酸水解或微生物转化的方法将糖苷转化为苷元。此前,判断大豆异黄酮糖苷是否水解及水解程度,通常是通过水解前后苷元含量的变化来判断,此方法操作过程相对繁琐。成都生物所发明的该种方法,通过商品豆粕经乙醇提取、提取液抽滤除杂质、减压蒸馏浓缩至无乙醇得水相、以水相为底物进行水解、用乙酸乙酯从水解液中萃取大豆异黄酮苷元、萃取液减压浓缩、浓缩相进行薄层层析、在紫外灯下观察层析结果,以此判断大豆异黄酮糖苷是否水解或水解的程度。该方法具有快速、准确等优点,具有良好的应用前景。(仪器信息网成都生物所发明判断大豆异黄酮糖苷水解的方法     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.