用离子交换法测定没食子酸锑钠(Sb-273)中的钠含量

没食子酸锑钠,即抗血吸虫病药物“Sb-273”,由水中结晶,是一种无色斜方块状透明晶体。根据晶体在120℃真空干燥后测定的元素分析值(C31.61％,H1.41％,Sb22.65％)符合组成式C_(14)H_8O_(11)SbNa_3(Ⅰ)。     

抗血吸虫病药物——双-[二没食子酸-(3,4)-亚锑酸]六钠——没食子酸锑钠(代号 Sb-273)的结构研究

没食子酸锑钠1是一种有效的、毒性低于吐酒石的、抗日本血吸虫病口服锑剂。1970年初,累积了一万五千多例可供分析的临床资料,经鉴定后正式投产推广应用。目前已用于一百六十多万病人,远期     

没食子酸的激光光解研究

The transient species of gallic acid(GA)have been studied by 266 nm nanosecond laser flash photolysis inaqueous solution and acetonitrile.The intermediate with absorption at 320 nm was identified as excited triplet state(~3GA~*),the decay rates of which were obtained in aqueous solution and acetonitrile respectively.Energy transferfrom ~3GA~* to β-carotene was observed and the energy transfer rate constant k_(ent)was determined to be 2.2×10~9mol~(-1)·L·s~(-1).GA underwent photoionization during photolysis and the quantum yield of photoionization was de-termined to be 0.12 at room temperature with KI as a reference.     

鸦胆子甙的化学结构研究

鸦胆子甙的分子式已初步定为C_(20)H_(32)O_9,系葡萄糖甙,示性式为C_(10)H_(11)(F)(OH)(CH_3)_3(内酯—O—CO—)(OC_6H_(11)O_5)。     

贝母植物碱化学结构的研究

贝母属植物百合科,品种繁多,遍于全世界,我国有小余种。其地下球茎为最常用的中药。仅作药用的种类就很复杂。形状大小皆不同。以浙贝、川贝和西贝为最常见。植物碱如吗啡、奎宁等具有显著的生理作用,在医药上有很大的功效。贝母是否含有生物碱,自然成为重要的课题。研究贝母植物碱最早的有:1888年德国Fragner研究德国产     

研究课程结构 改革化学教学

党的三中全会以来,在基本恢复正常的教学秩序后,高校化学教育工作者越来越多地谈论改革化学教学、提高教学质量问题。其中课程结构改革是各校普遍关心的问题。为此,教育部于1981年12月上旬在上海复且大学召开了“部属综合性大学化学系课程结构研究会议”。部属综合大学和重点师范大学化学系     

硼酸盐的结构化学

硼化合物在工业上有着广泛的应用,例如玻璃、陶瓷、搪瓷、制革、造纸等工业上常用到硼砂和硼酸;在医药上常用硼酸作消毒剂;在农业上硼作为微量元素肥料,它可使农作物产量提高;但更突出的是近年来由于高能燃料发展的需要,硼化合物更日益显得重要,对天然硼矿的开采和研究日渐增多。     

广东干草化学成分的研究

从干草中分离出五个化合物，并分别并鉴定为β－谷甾醇，香豆酸，棕榈酸，木樨草素和柯伊利素。     

STUDIES ON THE SEGMENTAL STRUCTURE OF POLYESTER-POLYETHER

In this paper the change of segment ratio, segmental sequence distribution and randonmess B of PET-PTMG block copolymer have been investigated by IR and ~(13)C-NMR spectra during the polycondensation reaction.     

醉马草化学成份的研究(Ⅰ)

醉马草(Achnatherum inebrians(Hance) Keng)是禾本科芨芨草属植物,分布在我国西北部,是牧场上一种毒草,目前有蔓延趋势。醉马草化学成份及毒理作用,国内外均未曾进行过研究。探明醉马草化学成份对发展畜牧业和医学事业都具有一定意义。     

THE EFFECT OF CHEMICAL STRUCTURE ON THE PHOTOSENSITIZING EFFICIENCIES OF PORPHYRINS

Abstract— A kinetic investigation was performed on the photooxidation of methionine sensitized by various porphyrins at different oxygen concentrations. The rate of photooxidation was found to be strongly dependent on the nature of the sensitizer. In the case of hematoporphyrin, chelation of Mg²⁺ and Zn²⁺ and especially of Cu²⁺ and Fe²⁺ caused a significant decrease of the photosensitizing efficiency. Fluorescence and/or flash photolysis studies showed that such a decrease is ascribed to an enhancement of the non-radiative decay of the first excited singlet state as well as to a reduction of the triplet lifetime. The sensitizing efficiency is also dependent on the nature of the porphyrin side chains. A reaction mechanism involving ¹O₂ as the oxidizing agent is proposed.     

EFFECT OF CHEMICAL STRUCTURE OF COMONOMERS ON THE PROPERTIES OF COPOLYESTERS

The effect of different kinds of comonomers with or without flexible chain on proper-ties of copolyesters, such as transition temperature, crystallization velocity, crystallinityand size of crystallites, is studied. The experimental results indicate the obvious differ-ence in properties between comonomers with iso- and ortho-structure of phenyl ring andcomonomers with flexible chain. The influence of chemical structure of comonomers onproperties of copolyesters is discussed.     

STUDIES ON THE CHEMICAL CONSTITUTIONS OF SONCHUS ARVENSIS L

Sonchus arvensis L. is one of perennial herbaceous plants of the composite family. It is abundant in China. It has the efficacy of for the treatment of fever, carbuncles and inflammation. Thirty-four compounds have been isolated and reported from the plant. In this paper, from the extraction of petroleum ether of sonchus arvensis L.,three chemical substances were isolated. By means of chemical and spectroscopic (IR, ¹H-NMR, ¹³C-NMR, ¹H-¹H COSY, MS) analysis, they were identified as n-hexacosanol (Ⅰ), α-amyrin (Ⅱ) and santoman (Ⅲ). Among them Ⅱ and Ⅲ are the first time isolated from this genus.     

半胱氨酸铜络合物的生成及其结构的研究

本文研究了在不同pH值下,半胱氨酸与CuCl_2络合生成的三种不同的络合物。在酸性溶液中,半胱氨酸与CuCl_2通过络合反应、自氧化还原反应,最后生成带氯桥的络合物[Cu_2(Ⅰ)Cl_2(cysH_2)]的白色粉末,(cysH_2为半胱氨酸)。在碱性溶液中,若反应在空气中进行,半胱氨酸与CuCl_2经氧化还原反应,结果生成天蓝色络合物(Cu_2(Ⅱ)(cyss)_2],(cyss~(2-)为胱氨酸根);若反应在绝氧条件下进行,它们则先络合,然后二聚成黑色络合物[Cu_2(Ⅱ)(cys)_2·6H_2O)。根据化学分析以及IR和ESR谱的研究,推测了这三种络合物的可能结构。     

煤中钠在燃料初期行为的研究

煤中钠是影响增压流化床（PFBC）和整体煤气化（IGCC）发展的一个重要因素。本文对煤中钠分别在800℃和900℃以及富氧和贫氧两种气氛下燃烧初期的释放规律进行了研究。结果表明,煤中钠在燃烧初期变化不大,钠的释放将主要发生在煤燃烧的后期。不同形态钠在燃烧初期的变化规律不同。随燃烧时间的增加水溶钠线性减小,盐酸溶钠线性增加。醋酸铵溶钠在燃烧初期总体表现为增加,不可溶钠则总体减少。研究显示,不同形态钠在燃烧初期存在转化,并主要表现咪水溶钠向盐酸溶钠的转化。温度和气氛对钠释放的影响主要取决于煤种。     

新疆一枝蒿挥发油化学成份的研究

新疆一枝蒿挥发油有明显的抗过敏作用。通过 GC/MS/DS 分析,表明有三十九种化学成份,并确证了其中十八种的结构及含量。