ABSTRACT
The original motivation for scaled particle theory (SPT) is to derive a simple equation of state for a bulk hard sphere (HS) fluid. It is now widely recognized that SPT provides also the surface tension of a HS fluid near a spherical hard wall, including three contributions, i.e., the planar surface tension and two bending rigidities due to the surface curvatures (integrated mean and Gauss curvatures). This conforms to the basic assumption of morphological thermodynamics. The existence of non-Hadwiger terms, i.e., higher-order curvature terms, has been evidenced recently. Augmenting SPT by only one non-Hadwiger term, i.e., third-order curvature term, allows us to obtain two new analytical theories, which not only describe very accurately bulk thermodynamic properties but also improve systematically surface ones with respect to SPT.
ABSTRACT
A fluid (a gas or a liquid) adsorbed in a porous material can behave very differently from its bulk counterpart. The advent of various synthesized materials with nanopores and their wide applications have provided strong impetus for studying fluids in confinement because our current understanding is still incomplete. From a large number of Monte Carlo simulations, we found a scaling relation that allows for connecting some thermodynamic properties (chemical potential, free energy per particle, and grand potential per particle) of a confined fluid to the bulk ones. Upon rescaling the adsorbed fluid density, the adsorption isotherms for many different confining environments collapse to the corresponding bulk curve. We also reveal the intimate connection of the reported scaling relation to Gibbs theory of inhomogeneous fluids and morphological thermodynamics. The advance in our understanding of confined fluids, gained from this study, also opens attractive perspectives for circumventing experimental difficulty for directly measuring some fluid thermodynamic properties in nanoporous materials.
ABSTRACT
It appears to be a common sense to measure the crowdedness of a fluid system by the densities of the species constituting it. In the present work, we show that this ceases to be valid for confined fluids under some conditions. A quite thorough investigation is made for a hard sphere (HS) fluid adsorbed in a hard sphere matrix (a quench-annealed system) and its corresponding equilibrium binary mixture. When fluid particles are larger than matrix particles, the quench-annealed system can appear much more crowded than its corresponding equilibrium binary mixture, i.e., having a much higher fluid chemical potential, even when the density of each species is strictly the same in both systems, respectively. We believe that the insight gained from this study should be useful for the design of functionalized porous materials.
ABSTRACT
AIM: To study the chemical components from the dried roots of Zanthoxylum dimorphophyllum Hemsl. var spinifolium Rhed. et Wils. METHODS: Modern chromatography was used to isolate chemical components and the compounds isolated from Zanthoxylum dimorphophyllum Hems1. var spinifolium Rhed. et Wils were identified by various spectral methods. RESULTS: Five compounds were isolated and identified as 6-(2',3'-dihydroxy-3'-methybutyl)-7-acetoxy-2H-1-benzopyran-2-one (I), 6-(2',3'-dihydroxy-3'-methybutyl)-7-(beta-D-glucopyranosyloxy)- 2H-1-benzopyran-2-one (II), hexacosanoci acid (III), aurepten (IV), 6-[6'-O-(-deoxy-alpha-L-mannopyranosyl)-beta-D-benzopyran-4-one (V). CONCLUSION: All of the above compounds were isolated from the plant for the first time, among them, I is a new compound.
Subject(s)
Coumarins/isolation & purification , Glucosides/isolation & purification , Plants, Medicinal/chemistry , Zanthoxylum/chemistry , Coumarins/chemistry , Fatty Acids/chemistry , Fatty Acids/isolation & purification , Glucosides/chemistry , Molecular Structure , Plant Roots/chemistryABSTRACT
OBJECTIVE: To evaluate the pharmacological effect of tetraploid Isatis indigotica Fort. METHODS: Comparing these actions of tetraploid I. indigotica with those of the diploid parent. RESULTS: These actions of tetraploid I. indigotica were obviously stronger than those of the diploid parent. The pharmacological effect of leaves was greater than that of roots with identical ploidy. CONCLUSION: Tetraploid I. indigotica is a new line of better quality, deserving to be exploited and utilized on a large scale.
Subject(s)
Antiviral Agents/pharmacology , Drugs, Chinese Herbal/pharmacology , Isatis/genetics , Plants, Medicinal/genetics , Animals , Antitoxins/pharmacology , Chick Embryo , In Vitro Techniques , Influenza A virus/drug effects , Limulus Test , Plant Leaves , Plant Roots , PolyploidyABSTRACT
OBJECTIVE: Investigating the chemical constituents of Radix Polygoni Multiflori Preparata. METHODS: Compounds were isolated from the CHCl3 extract with column chromatography on silica gel, and identified on the basis of spectral analysis(IR, EI-MS, 1H-NMR, 13C-NMR) and phytochemical properties. RESULTS: Two compounds were isolated and identified as 1,2-dihydroxynonadecone-3(I) and gallic acid(II). CONCLUSION: Compound I is a new compound.
Subject(s)
Drugs, Chinese Herbal/chemistry , Ketones/isolation & purification , Plants, Medicinal/chemistry , Polygonum/chemistry , Gallic Acid/chemistry , Gallic Acid/isolation & purification , Hot Temperature , Ketones/chemistry , Plant Roots/chemistry , Technology, PharmaceuticalABSTRACT
AIM: To investigate the cardiovascular active constituents of Radix Polygoni multiflori Preparata. METHODS: Compounds were isolated from the water soluble extract with column chromatography of Sephadex, ODS and HPLC. The compounds were identified on the basis of spectral analysis (IR, EI-MS, FAB-MS, 1HNMR, 13CNMR, 2D-NMR) and phytochemical properties. Its inhibitory effect on the proliferation of bovine vascular smooth muscle cells were bioassayed in vitro. RESULTS: One compound was isolated and identified as: 2,3,5,4'-tetrahydroxystilbene-2-O-(6"-O-alpha-D- glucopyranosyl)-beta-D-glucopyranoside. CONCLUSION: Compound I is a new compound with cardiovascular activity.
Subject(s)
Disaccharides/isolation & purification , Plants, Medicinal/chemistry , Polygonum/chemistry , Stilbenes/isolation & purification , Animals , Cattle , Cell Division/drug effects , Cells, Cultured , Disaccharides/chemistry , Disaccharides/pharmacology , Molecular Conformation , Molecular Structure , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/drug effects , Myocytes, Smooth Muscle/cytology , Myocytes, Smooth Muscle/drug effects , Plant Roots/chemistry , Stilbenes/chemistry , Stilbenes/pharmacologyABSTRACT
This paper first suggests that 2,4 (1H,3H) quinazolinedione (QZL) may be used as a quality control standard for the Chinese herbal drugs Daqingye (Folium Strobilanthis et Polygoni) and Banlangen (Radix Strobilanthis) as well as its preparations. QZL was found for the first time from the above mentioned two Chinese herbal drugs which has a representative property. Its content is stable. This made it possible to solve the difficulty of quality control for the preparations "antipyretic and common cold granules" and "Banlangan granules" and provide a reliable assay method to evaluate the quality of the herbal preparations. By changing the wavelength and using gradient elution in HPLC, 3 constituents can be determined through one injection by the present method, thus the time of determination may be shortened and the efficiency of assay increased. The method showed good linearity (r = 0.99998, n = 4) in the range of 0.2-3.2 micrograms/ml of QZL, the average recovery was above 95% with RSD < 1.5% (n = 3). HPLC condition: Column: LiChrosorb RP 18; elution gradient: methanol from 35% to 90% in water solution; determination wavelength: 226 nm and 288 nm.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemistry , Drugs, Chinese Herbal/chemistry , Quinazolines/analysis , Chromatography, High Pressure Liquid/methods , Indigo Carmine , Indoles/analysis , Quality ControlABSTRACT
Seven compounds have been isolated from the whole plant of Strobilanthes cusia (Nees) O. Ktze. Three of them are triterpenes (I-III), two are indole alkaloids (IV, V), two are quinazolinone alkaloids (VI, VII). On the basis of spectral analysis and physicochemical properties, their structures were established as lupeol (I), betulin (II), lupenone (III), indigo (IV), indirubin (V), 4(3H)-quinazolinone (VI), 2,4(1H,3H)-quinazolinedione (VII). VI and VII were found from natural plant for the first time. The results of the pharmacological tests demonstrate that compound V has anticancer activity and compound VI has hypotensive action. Compound VII can be quantitatively determined by HPLC, which may serve as a quality control standard for materia medica and its preparations. Compounds VI and VII have been confirmed by means of synthesis.
Subject(s)
Antihypertensive Agents/isolation & purification , Drugs, Chinese Herbal/chemistry , Quinazolines/isolation & purification , Antihypertensive Agents/chemistry , Molecular Structure , Quinazolines/chemistry , QuinazolinonesABSTRACT
A Survey of the source plants of Semen Armeniacae Amarum and their distribution was made in 14 provinces of China. A new source plant of Semen Armeniacae Amarum, Armeniaca zhidanensis, was found and all the source plants of Semen Armeniacae Amarum were grouped in 7 distribution areas.
Subject(s)
Plants, Medicinal , China , Conservation of Natural Resources , Fruit/classification , Plants, Medicinal/classification , SeedsABSTRACT
The cuticular patterns on leaf surface of Sarcandra glabra (Thunb.) Nakai were studied with scanning electron microscope. It was found that the cuticular patterns vary not only with the district of specimen collection, but also with the developmental stage of the leaf. The characteristics of the cuticular patterns are described in detail with 2 plates of illustrations.
