广防己挥发油的GC-MS指纹图谱研究

防己药材主要分粉防己和木防己两类,木防己包括广防己和汉中防己。广防己为马兜铃科植物广防己AristolochiafangchiY.C.WuexL.D.Chou.etS.M.Hwang的干燥根,习称"木防己"、"水防己",主产于广东、广西,具有祛风止痛、清热利水之功效。广防己主要成分为为生物碱及挥发油,己有报道的生物碱主要有:木防己碱、异木防己碱、木兰花碱、木防己胺、大防己宾碱、甲门尼萨任碱。挥发油成分未见报道,本文采用气相色谱-质谱(GC-MS)测定广防已挥发油成分,建立能够反映出定性、定量信息的GC-MS指纹谱图。结果表明:挥发油中主要含有β-古芸烯     

A New Flavonoid Ketohexofuranoside from Leaves of Crataegus pinnatifida Bge.var. major N.E.Br.

Crataegus pinnatifida Bge.var.major N.E.Br. is widely distributed in the northeast part of China. It is used as a medicinal plant to improve digestion, remove retention of food, promote blood circulation and resolve blood stasis both in traditional and folk medicine 1. Preparations of Crataegus leaves improve the heart function, the coronary blood supply and arrhythmia2. Up to now, fifty flavonoids have been isolated from Crataegus3,4. In our previous paper, some new flavonoid glycosides we…     

Two New C—glucoside Flavonoids from Leaves of Crataegus pinnatifida Bge. var. major N.E.Br.

Two new C-glucoside flavonoids,namely 8-C-β-D-（2″-O-acetyl) glucofuranosyl apigenin and 3″-O-acetylvitexin, were isolated from beaves of Crataegus pinnatifida Bge. var. major N.E.Br.Their structures were elucidated by the spectroscopic means and chemical evidence.     

HPLC测定河套大黄中的土大黄苷含量

从河套大黄中分离纯化出活性成分土大黄苷,作为自制的标准品,利用KromasilTM C(18)(250 mm×4.6 mm I.d.,5μm)反相色谱柱,以V(甲醇):V(乙腈):V(水)=35:5:60为流动相,以320mm为检测波长,对河套大黄中土大黄苷进行测定.土大黄苷在0.427～4.190μg范围内与峰面积呈良好线性关系(r=0.9994),平均回收率为99.12%.该方法为河套大黄的质量控制奠定了基础.     

Structural characterisation of a water-soluble polysaccharide from tissue-cultured Dendrobium huoshanense C.Z. Tang et S.J. Cheng

A water-soluble polysaccharide TC-DHPA4 with a molecular weight of 8.0 × 10⁵ Da was isolated from tissue-cultured Dendrobium huoshanense by anion exchange and gel permeation chromatography. Monosaccharide analysis revealed that the homogeneous polysaccharide was made up of rhamnose, arabinose, mannose, glucose, galactose and glucuronic acid with a molar ratio of 1.28:1:1.67:4.71:10.43:1.42. The sugar residue sequence analysis based on the GC-MS files and NMR spectra indicated that the backbone of TC-DHPA4 consisted of the repeated units:→6)-β-Galp-(1→6)-β-Galp-(1→4)-β-GlcpA-(1→6)-β-Glcp-(1→6)-β-Glcp-(→. The sugar residue sequences β-Glcp-(1→)-α-Rhap-(1→3)-β-Galp-(1→, β-Glcp-(1→4)-α-Rhap-(1→3)-β-Galp-(1→, β-Galp-(1→6)-β-Manp-(1→3)-β-Galp-(1→, and α-l-Araf-(1→2)-β-Manp-(1→3)-β-Galp-(1→ were identified as the branches attached to the C-3 position of (1→6)-linked galactose in the backbone.     

Kalman滤波分辩交流示波极谱图中重叠切口

交流示波极谱过去仅用于简单体系的测定,当溶液中含有大量干挠离子时,dE/dt～E曲线上将产生许多切口,它们互相重叠干扰,无法进行定量测定,本文首次将Kalman滤波算法引入交流示波极谱,用于解析多组分共存时的示波图,将重叠切口进行分离,使干扰共存时定量测定成为可能。     

铵梯脲混合炸药中改性硝酸脲和硝酸铵含量的测定

论述了铵梯脲混合炸药中改性硝酸脲和硝酸铵组分含量的一种快速准确的化学分析测定方法。该法在研制和生产铵脲类炸药的过程中,对选择最佳配比,控制生产和质量把关等有着重要的指导作用。同时笔者对测定方法,反应原理,影响因素等作了深入的探讨与研究。     

瓯柑中微量元素的测定

采用电感耦合等离子体原子发射光谱仪(ICP-AES)，对瓯柑籽、果皮、果肉汁中10种微量元素进行了测定。结果表明，瓯柑籽、果皮、果肉汁中含有丰富的人体必需微量元素，且瓯柑籽、果皮中的微量元素含量普遍高于肉汁中的微量元素的含量，这为瓯柑药效功能的进一步研究和资源综合开发利用提供科学依据。     

选相示波伏安法

选相示波伏安法毕树平，都思丹，高鸿（南京大学化学系，２１０００８）关键词示波计时电位法，选相示波伏安法，切口示波计时电位法是利用ｄＥ／ｄｔ～Ｅ曲线上切口的高度或深度进行定量分析的方法［１］，但由于ｄＥ／ｄｔ曲线主要反映充电电流的变化，从而使该方法的检...     

Borchelate und Bormetallchelate, 4. Mitt.

The i.r., u. v.,¹H n.m.r.,¹³C n.m.r., and¹¹B n.m.r. spectra of several substituted diphenylboron chelates derived from salicylaldehyde azomethines were compared with respect to the influence of the amine substituentR. O–B–N-6-ring constitution of the chelates29–32 [R=OH, NH₂, NHC₆H₅, N(CH₃)₂] can be deduced from the spectra.

Als 3. Mitt. gilt:F. Umland undE. Hohaus mit Beiträgen vonW. Riepe, K. Brodte, C. Schleyerbach undD. Szonn. Untersuchungen über borhaltige Ringsysteme vom Chelattyp. Forschungsbericht des Landes Nordrhein-Westfalen Nr. 2538. Opladen: Westdeutscher Verlag. 1976.     

Experimental study of a d.c. oxygen glow discharge by V.U.V. absorption spectroscopy

Vacuum ultraviolet absorption spectroscopy has been used to measure the concentration of oxygen molecules O₂(³), metastable singlet O₂(¹) molecules, atoms, and ozone in a d.c. glow discharge. The axial electric field, the electronic density, and the gas temperature are also determined. This set of measurements is presented for the positive column of a glow discharge created in a 1.6-cm-diameter Pyrex tube, for a pressure between 0.2 and 5 Torr and a d.c. current up to 80 mA.     

INDO Investigation of the halogen N.Q.R. frequencies and 14N nuclear quadrupole coupling constants of halothiophenes and halopyridines

The ³⁵Cl, ⁷⁹Br, and ¹²⁷I N.Q.R. frequencies of a number of halothiophenes and halopyridines and the ¹⁴N nuclear quadrupole coupling constants of halopyridines have been determined in terms of the Kaplansky-Whitehead theory with the INDO MO approximations using a consistent set of atomic parameters derived from SCF Hartree-Fock calculations. The theoretical spectral properties are in satisfactory overall agreement with experiment. This result supports the validity of using the above method to provide reliable predictions of N.Q.R. parameters for heteroaromatic systems.This work was carried out with the support of the Consiglio Nazionale delle Ricerche (C.N.R.) of Italy.     

P. M. R. Spectroscopic Analysis of Bacterial Polysaccharides Containing Pyruvic Acid

Abstract

The characteristic p.m.r. signal at τ 8.4–8.6 given by the CH₃-C group of a pyruvic acid ketal (1-carboxyethylidene derivative)may be used to demonstrate the presence of such a substituent in polysaccharides. Similar signals are given when the pyruvic acid ketal is methylated or reduced. The method is convenient for monitoring purification procedures and chemical transformations of polysaccharides such as are involved in structural studies. In certain cases the molar ratio of pyruvic acid may be estimated.     

Determination of Methylmercury by Phase-Sensitive A. C. Polarography

Abstract

The polarographic reduction of methylmercury in aqueous medium takes place in two steps, each of which involves the transfer of a single electron. The first reduction step proceeds reversibly both in direct current and in sinusoidal alternating current. Since the polarograms corresponding to this step are well defined, they can be successfully used to determine methylmercuric compounds by phase-sensitive sinusoidal a.c. polarography, in the concentration range 1 × 10^?7 ?1 × 10^?4 mole.dm.^?3     

珠子参化学成分分析

从珠子参根茎中分离得到7个化合物. 利用核磁共振、 质谱和红外等手段, 并结合其理化性质, 鉴定了其结构, 它们分别是24(R)-珠子参苷R1, 6-O-[β-D-吡喃葡萄糖基(1→2)-β-D-吡喃葡萄糖基]-20-O-[β-D-吡喃葡萄糖基(1→4)-β-D-吡喃葡萄糖基]-20(S)-原人参三醇、 6″-乙酰基-人参皂苷Rd、 人参皂苷Rf、 竹节参皂苷Ⅳa、 人参皂苷Rd和竹节参皂苷Ⅴ. 其中, 24(R)-珠子参苷R1和6-O-[β-D-吡喃葡萄糖基(1→2)-β-D-吡喃葡萄糖基]-20-O-[β-D-吡喃葡萄糖基(1→4)-β-D-吡喃葡萄糖基]-20(S)-原人参三醇为2个新化合物, 6″-乙酰基-人参皂苷Rd 和人参皂苷Rf为首次从珠子参根茎中得到.     

Fast sweep a.c. polarography

Summary The design of a fast sweep a.c. polarograph suitable for recording second harmonic and intermodulation polarograms is described. The instrument was found suitable for determining reducible species down to concentrations of approximately 2×10^–7 M. By integrating the faradaic response a considerable improvement in precision can be obtained.

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Fast-Sweep-Wechselstrompolarographie

Zusammenfassung Ein Polarograph wird beschrieben, der zur Aufnahme von Polarogrammen mit Hilfe der 2. Harmonischen und der Zwischenmodulation geeignet ist. Reduzierbare Substanzen können bis herab zu 2 · 10^–7 M erfaßt werden. Durch Integration des Faradaystroms kann eine beträchtliche Verbesserung der Genauigkeit erreicht werden.

Lecture presented at Euroanalysis I Conference, 28. 8.–1. 9.1972 in Heidelberg, Germany.     

Ginsenoside-Rg6, a Novel Triterpenoid Saponin from the Stem-Leaves of Panax ginseng C. A. Mey.

A novel dammarane-type triterpene oligoglycoside, named ginsenoside-Rg6 3, was isolated from the stem-leaves of Panax ginseng C.A.Mey., together with two known ones, 20(S)-ginsenoside-Rg2 1 and 20(R)-ginsenoside-Rg2 2.On the basis of chemical and physicochemical evidence , the structure of ginsenoside-Rg6 have been elucidated as 6-O-α-L-rhamnosyl-(1→2)-β-D-glucopyranosyl-dammarane-(E)-20(22), 24-diene-3β, 6α, 12β-triol.     

伟大的分析化学家——I．M．Kolthoff

本文简介Ｋｏｌｔｈｏｆ的主要工作并初步探讨了他的学术、教育思想的某些特点     

Laser Doppler anemometry under plasma conditions. Part I. Measurements in a d.c. plasma jet

A study is presented on the use of laser Doppler anemometry (LDA) techniques for the measurement of the gas and particle velocities under plasma conditions. Experimental data is presented for a d.c. plasma jet in which alumina particles are injected under different operating conditions. The results reveal that the plasma velocity at the exit of the jet is of the order of 200–300 m/s. The intensity of turbulence is as high as 30 to 40% in the free shear layer and the particle velocity distribution is shown to be asymmetric, with particle dispersion in the plane of injection considerably more important than that in the perpendicular direction. The average particle velocity depends on the composition of the plasma gas, the torch current, and power.