bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthèse et structure cristalline de la dihydro‐2, 3 (nitro‐5 pyridyl‐2)‐3 propyl‐6 thioxo‐2 1h pyrimidinone‐4
Authors: Dupont L. , Dideberg D. , Jamoulle J. C. , Lapière C. L. , Bourdais J. 
Published: September 2010

AbstractCondensation of 2‐chloro‐5‐nitro pyridine with propyl‐thiouracil has been carried selectively on the S as well as on N(3) of propylthiouracil. The crystal structure of the latter compound (C12H12N4O3S) has been determined. Space group is P21, Z=8, a=12.476(4), b=22.625(5), c=9.878(4)Å, B=90.883(10)°. The four independent molecules have almost the same conformation with the nitro group rotated by 7° to 11° from the pyridine rings: the dihedral angles between the latter and the pyrimidine planes are included in the limits 80 to 84°.
Mechanistic Aspects of Reduction of Ditelluratocuprate (III) by α‐Hydroxy Acids in Alkaline Medium
Authors: Murthy C. P. , Sethuram B. , Rao T. Navaneeth 
Published: September 2010

AbstractThe kinetics and mechanism of oxidation of lactic acid, glycolic acid and mandelic acid by tellurate complex of trivalent copper in alkaline medium was studied. The kinetics were monitored by following the disappearance of Cu (III) spectrophotometrically at 405 nm. The reactions are first order in each [reactant] and fractional order in [ligand] and [OH−]. The results are discussed with reference to electron density on ‐OH− or ‐COO substrate sites and probable mechanism suggested.
Bepaling van Aantalgemiddeld Molecuulgewicht en Heterogeniteitsindex Via Diffusie‐Experimenten
Authors: Peeters F. A. H. , Soeteman A. A. 
Published: September 2010

AbstractThe determination of averages of diffusion coefficients and among others, from them, the number‐average molecular weight, becomes possible after reformulation of Sundelöf's method of processing of free diffusion data. An index of heterogeneity may be calculated too.
Characterization of Structural Isomers in Commercial 2‐Hydroxypropyl Methacrylate
Authors: Schacht Etienne , Bruyn André De , Simondsxs Ronald , Goethals Eric 
Published: September 2010

AbstractCommercial 2‐hydroxypropylmethacrylate contains a structural isomer: 2‐hydroxy‐1‐methyl‐methacrylate. The mixture was analysed by GC‐MS and 360 MHz 1H NMR. The NMR parameters for both isomers are reported.
Reductive Couplings of Ketones by Low‐Valent Titanium, Prepared from TiCl4 and Reducing Agents
Authors: Dams R. , Malinowski M. , Geise H. J. 
Published: September 2010

AbstractThe reductive coupling of benzophenone to tetraphenylethene was studied. The coupling reagent, low‐valent titanium, was obtained after reduction of TiCl4. The results are compared with those of similar couplings using low‐valent titanium obtained after reduction of TiCl3.E.s.r. measurements and chemical observations show that the TiCl4‐and the TiCl3‐system behave completely analoguous with respect to reduction to low‐valent titanium as well as with respect to reactivity towards ketones and alcohols.
Étude Structurale des Analogues de la Minaprine: 1. Structure Moléculaire du Dichlorhydrate de la Desméthylminaprine
Authors: Michel A. , Gustin R. , Evrard G. , Durant F. 
Published: September 2010

AbstractThis paper initiates a series of structural studies on analogs of minaprine, a psychotropic drug, in order to establish structure‐activity relationships. The results of the crystal structure analysis of the desmethylminaprine.2 HCl.H2O are related. In particular, we discuss the electronic delocalization in the aminopyridazlnium moiety.
Crystal Structure of Baurenyl Acetate from Tabernaemontana Longipes Donn. Smith
Authors: Tinant B. , Germain G. , Declercq J. P. , van Meerssche M. , Ciccio J. F. , Hoet P. 
Published: September 2010

AbstractThe structure of the title compound (D:C‐Friedours‐7‐en‐3‐ol acetate 3β) has been determined by single crystal X‐ray diffractometry. Crystal data are as follow: orthorhombic, P212121, a = 8.291(1), b = 11.084(3), c = 30.041 (8) Å, V =2761(1) Å3, Dx = 1.13 Mg m−3 for Z = 4.
Les Polymères Bioactifs XI. Insolubilisation de la β‐Amylase Sur les Dérivés de la Cellulose
Authors: Bouzaher Y. , Dumitriu S. , Simionescu Cr. 
Published: September 2010

AbstractThe immobilization of β‐amylase on acid chloride of carboxymethylcellulose (DS = 2.02) and BIOZAN R is presented. Kinetic studies established the following conditions for a optimum coupling: pH = 8.4, time = 2 h, temperature = 5°C. The immobilization on BIOZAN R was carried out by using the BIOZAN R acid chloride or by activation with dicyclocarbodiimide. The results showed that the nature of the carrier and the method of immobilization determine directly the quantity and the activity of the coupled β‐amylase.
The Crystal Structure of (3R,65)‐3‐Benzyl‐4‐Methyl‐1, 4‐Diaza‐Bicyclo [4.4.0] Decan‐2,5‐Dione
Authors: van Poucke M. , Lenstra A. T. H. 
Published: September 2010

AbstractThe piperidine ring in the title compound is in the chair conformation, whereas the diketopiperazine ring has a boat form. The benzyl group is axially positioned and folded above the diketopiperazine ring. No dimerisation is observed.
Isolement par Chromatographie Liquide a Haute Performance Préparative D'Appariement D'Ions et Identification des Constituants Majeurs du Jaune de Quinoléine (C.I. 47005)
Authors: Masiala‐Tsobo C. , Gelbcke M. , Dumont L. , Parmentier F. , Grimée R. 
Published: September 2010

AbstractA qualitative and quantitative study of the constituents of quinoline yellow (C.I. 47005) in several samples is presented here. The isolation through preparative ion pairs HPLC of these constituents, followed by a spectroscopic examination (UV‐visible, IR, 1H ‐ NMR) and by a study which compares them to synthesized derivatives, shows that quinoline yellow commercial samples contain chiefly disodic salts of 2‐(2′‐quinolyl) 1, 3‐indandione sulfonic acids sulfonated respectively on 5,6′ and 5,8′ positions. Some samples contain also important quantities of the last mentioned compound methylated on 6′ position.
Étude en RMN du Carbone‐13 de Quelques Colorants (Quinoleinyl‐2′)‐2 Indanedione‐1, 3 Sulfones
Authors: Gelbcke M. , Masiala‐Tsobo C. , Dumont L. , Parmentier F. , Grimée R. 
Published: September 2010

AbstractCarbon‐13 nuclear magnetic resonance spectra of some sulfonated 2‐(2′‐quinolyl)‐1, 3‐indanedione dyes have been reported and fully assigned.
Amino Steroids ‐ 12‐Oxygenated Heteroconanine Derivatives. Preparation and Properties
Authors: van De Woude G. , Biesemans M. , van Hove L. 
Published: September 2010

AbstractTreatment of N‐methyl‐5α‐conaninium iodides, diversely oxygenated at position 12, with a boiling solution of potassium hydroxide in ethylene glycol most often appears to be a satisfactory method to obtain the title compounds. The latter are free bases of reversed configuration at C‐20 with regard to the starting compounds. The conversion is however never complete: the conanine base and an isomer of the normal Hofmann elimination product are always formed, occasionally together with minor degradation products.Comparison of the properties of heteroconan‐3β‐ols carrying an oxygen function at C‐12 with those of the corresponding conan‐3β‐ols revealed differences which can be used as rules to distinguish the epimers of a pair. Deviations from the generally observed regularities seem to be dependent on the nature of the oxygen function located at C‐12.
Structural Studies of 2‐Aceto‐1‐naphthol‐Salicyl Hydrazone Complexes of Cu(II), Co(II), Ni(II), Mn(II), Ce(III) and UO
Authors: Khattab M. A. , Soliman M. S. , El‐Enany G. 
Published: September 2010

AbstractComplexes of Cu(II), Co(II), Ni(II), Mn(II), Ce(III) and UO2+2 with 2‐aceto‐ 1 ‐naphthol‐N‐salicly hydrazone (AN.S.H) have been prepared and characterized on the basis of analytical, UV, visible, and IR spectroscopic, conductance and magnetic moment data. The measurements revealed the existence of mono‐ and bis‐ligand complexes. The electronic spectra of the complexes in dimethyl formamide solution indicate that the bis‐ligand complexes of Cu, Ni, Co and Mn have octahedral structure, and the mono‐ligand complexes of Cu and Ni are square planar. Spectrophotometric studies suggest the use of this ligand for the micro‐determination of metal ions in solution. The apparent formation constants of the complexes have been determind.
1H NMR study of 1, 6‐Anhydro‐β‐D‐Glucopyranose Tosylated at 2‐ and/or 4‐Position
Authors: van Rijsbergen Ronan , Anteunis Marc J. O. , De Bruyn André 
Published: September 2010

AbstractThe 1H nmr spectra of 1,6‐anhydro‐2‐0‐tosyl‐, 1,6‐anhydro‐4‐0‐tosyl‐ and 1,6‐anhydro‐2,4‐di‐O‐tosyl‐β‐D‐glucopyranose have been analyzed. The data allow to discriminate between the two monosubstituted levoglucosans.
Hydrogenation and Other Side‐Reactions During the Reductive Coupling of Ketones with Lowvalent Titanium (McMurry Synthesis)
Authors: Malinowski R. Dams , Geise H. J. 
Published: September 2010

AbstractActive titanium slurries, effective in the McMurry coupling reaction of ketones to olefins, are also hydrogenation agents. Sometimes they also promote isomerisation of the originally formed olefin as well as aldol type and pinacol type condensations under special reaction conditions.The most prominent factors promoting hydrogenation are the use of high ratios LiAlH4: TiCl3 and low temperatures in the formation of the low‐valent titanium species.
The Analysis of the Homogeneous Saponification Method Applied to High Pressure Ethylene Vinylacetate Copolymers. Part I: Kinetical Consideration
Authors: Koopmans R. J. , van Der Linden R. , Vansant E. F. 
Published: September 2010

AbstractThree high pressure ethylene vinylacetate (EVA) copolymers having a mol % VA between 0 and 20 are transformed into ethylene vinylalcohol vinylacetate (EVALVA) terpolymers by an homogeneous saponification method. The acetoxy‐hydroxide conversion proved to be caused by two similtaneously occuring reactions, a saponification and a transesterification. The overall reaction, however, could be discribed by second order kinetics. The lower VA conversion rate of EVA types having 3.5 vs 12.0 and 18.8 mol % VA was explained a combined steric and neighbouring group effect. Finally a mechanism applicable to any EVA type copolymer was forwarded to comprehend the acetoxy‐hydroxide conversion.
π‐π Molecular Complexes of Nitrones with Tetracyanoethylene and 1, 4‐Benzoquinones
Authors: Nour‐el‐Din Ahmed M. , Mourad Aboul‐Fetouh E. 
Published: September 2010

AbstractCharge‐transfer molecular complexes between some nitrones with different substituents and tetracyanoethylene, 2, 3‐dichloro‐5, 6‐dicyanobenzoquinone and chloranil have been studied in methylene chloride solution at 25° C. The maximum absorption wavelengths, stoichiometry, apparent formation constants and transition energies confirm the formation of the π ‐ π molecular complexes. The effect of solvent, the formation and stability of these complexes have been discussed.
Structure Cristalline des Complexes du Cuivre(I) Avec la Thiourée III. Complexes Contenant des Cations Cu4 (tu)4 +6 DE TYPE ADAMANTANE: A. LE BIS (BISULFATE) SULFATE D'HEXAKIS (THIOUREE)‐TETRACUIVRE(I) MONOHYDRATE Cu4 [SC(NH2) 2] 6 (HSO4) 2SO4.H2O B. LE SULFATE D'HEXAKIS (THIOUREE)‐TETRACUIVRE (I) DIHYDRATE Cu4 [SC(NH2) 2] 6 (SO4) 2 · 2H2O
Authors: van Meerssche M. , Kamara R. , Germain G. , Declercq J. P. 
Published: September 2010

AbstractThe two title compounds have been prepared from sulfuric (A) or acetic (B) acid solution of CuSO4 and thiourea. Their crystal structure were determined from X ray diffractometer measurements. The crystal data are as follows: A: triclinic, space group P1, a = 13.863 (5), b = 13.385 (5), c = 10.251 (3)Å, α = 68.56 (2), β = 70.11 (2), γ = 82.51 (2)°, V = 1664. 9 (1.0)Å3 and Z = 2 for Dx = 2.03 Mg m−3. B: orthorhombic, Pbca, a = 35.487(12), b = 9.970(3), c = 33.147(10)Å, V = 11727. 6(6.4)Å3 and Z = 16 for Dx = 2.13 Mg m−3. In both compounds the cationic fragment Cu4S6 exhibits an adamantane‐type structure. The anion H2(SO4)4 ‐3 of the A compound shows very short hydrogen bonds (2.43 Å).
Solvent Effect Upon the Polarity and Stability of Pentabromophenol‐Amine Adducts
Authors: Majerz I. , Malarski Z. , Sobczyk L. 
Published: September 2010

AbstractDipole moments and formation equilibrium constants of a series of pentabromophenol complexes with ternary amines in carbon tetrachloride, chloroform and 1,2‐dichloroethane were measured. The values of the hydrogen bond polarity, Δμ, were correlated with the ΔpKa parameter and the effect of the solvent activity on the charge distribution in hydrogen bonded complexes was discussed.
Multielement Determination of Trace Elements in Plant Samples by Inductively Coupled Plasma Emission Spectroscopy: Preconcentration and Elimination of Alkaline Earth Metal Interferences
Authors: Camerlynck R. , Martens R. , Verloo M. 
Published: September 2010

AbstractDirect trace element determination with ICP‐spectrometry in plant samples is hampered by severe interferences of Ca and Mg.A method is proposed to eliminate chemically the interfering concomitants while at the same time several trace elements are preconcentrated with the aid of a chelating ion exchange resin.
Structure and Reactivity of a Stable Oxirane Derived from 2,2,6,6‐Tetrachloro‐3,3,5‐Trimethylcyclohexanone and Methanolic Sodium Methoxide
Authors: De Buyck Laurent , Dewaele Marc , De Kimpe Norbert , Verhé Roland , Schamp Niceas 
Published: September 2010

AbstractThe title ketone 1 afforded > 95% of fairly stable t‐1,3,3‐trichloro‐t‐2‐methoxy‐4,6,6‐trimethyl‐1,2‐epoxycyclohexane (2) by reaction with cold methanolic sodium methoxide. Heating or contact with sulfuric acid or boron trifluoride caused stereospecific rearrangement of 2 into t‐2,3,3‐trichloro‐2‐methoxy‐4,6,6‐trimethylcyclohexanone (3). On the contrary, rearrangement into the epimeric ketone 4 was induced by trifluoroacetic or dichloroacetic acid in carbon tetrachloride. Epimer 4 was distinctly more reactive than 3 towards dehalogenation with zinc in acetic acid and towards sodium methoxide. Good yields of 3,3‐dichloro‐4, 6,6‐trimethyl‐1,2‐cyclohexanedione (7) were obtained from 2, 3 or 4 in hot solutions of zinc chloride in acetic acid.The symmetric 2,2,6,6‐tetrachloro‐3,3,5,5‐tetramethylcyclohexanone (8) showed analogous reactions.
Catalytic Activity of Pt/AlPO4 and Related Systems. II.‐ Gas‐Phase Hydrogenation of Xylenes
Authors: Aramendia M. A. , Borau V. , Jimenez C. , Marinas J. M. 
Published: September 2010

AbstractIn the present paper data are reported on the gas‐phase hydrogenation of O‐, m‐, and p‐xylene and O‐, m‐, and p‐ethylmethylbenzene using a pulse reactor. New systems obtained by supporting Pt on AlPO4 ‐Al2O3 (75/25), pure AlPO4 and SiO2 ‐AlPO4 (80/20) have been used as catalysts. The effect of the reduction temperature of the catalysts and the hydrogen pressure on the selectivity to cis‐ and trans‐dimethylcyclohexanes and ethylmethylcyclohexanes has been investigated. The results obtained are interpreted by assuming a Horiuti‐Polanyi mechanism, with suprafacial addition of hydrogen.
Contribution a l'Étude Électrochimique de Derives de L'Acide Mercapto‐3 Pyridine Carboxylique‐2
Authors: Lejeune R. , Vandenbalck J. L. , Patriarche G. J. , Lapiere C. L. 
Published: September 2010

Abstract2‐methoxycarbonyl‐1‐methyl‐3‐methylthio‐pyridinium iodide (Ia), 2‐carboxy‐1‐methyl‐3‐methylthio‐pyridinium iodide (Ib), 3‐mercapto‐2‐methoxycarbonyl‐1‐methyl‐pyridinium iodide (IIa) and 2‐carboxy‐3‐mercapto‐1‐methyl‐pyridinium iodide (IIb) have been studied by recent electrochemical techniques such as direct (DC), alternating current (AC), differential pulse polarography (DPP) and cyclic voltammetry.The influence of the pH has been observed and put in connection with the structure of the compounds studied.Cyclic voltammetry has permitted to differentiate Ia and Ib by the existence of reversible phenomena that become evident only for the carboxycompound.The study of the influence of the concentration has permitted to set up the best conditions for the determination of these compounds by direct current (DC) and differential pulse polarography (DPP).
Contribution a L'étude Électrochimique de Derives de L'Acide Mercapto‐3 Pyridine Carboxylique‐2
Authors: Lejeune R. , Vandenbalck J. L. , Patriarche G. J. , Lapiere C. L. 
Published: September 2010

Abstract3‐methylthiopyridine‐2‐carboxylic acid and its methylic ester have been investigated by recent electrochemical techniques such as direct (DC), alternating (AC) current, differential pulse polarography (DPP), controlled potential coulometry and cyclic voltammetry. The influence of polarographical parameters, pH and concentration on the electrochemical behaviour of these compounds permits to explore several of their chemical properties. On the other hand, the optimal conditions for the quantitative determination of traces have been established.
Diffusie‐, Visceus en GPC‐Gedrag van Dextranen in Water als Functie van Hun Molecuulgewicht
Authors: Soeteman A. A. , Peeters F. A. H. 
Published: September 2010

AbstractFor a number of dextrans (Pharmacia) with known molecular weight M, the viscous and GPC behaviour, in aqueous solutions at 30 °C, have been investigated. In spite of branching, well‐defined calibration curves based on M or the viscosity number [η], could be constructed, proving the homologous character of this dextrans. The dispersion‐corrected Mark‐Houwink relation is: [η] = 7.53. 10−2. M0. 523 (ml/g), for 104 ≤ M ≤ 105. At higher molecular weights the exponent decreases up to 0.34. Processing of classical diffusion experiments, following Sundelöf, enables determination of a number of averages of diffusion coefficients Dp, with p > ‐1/2, from the deviation function, and, moreover, of the reduced height‐area ratio DA. Using the chromatograms, the M‐based calibration curve and these D‐averages, we corrected the D, M‐relation for dispersion: D = 8.84. 10−5. M−0. 476 (cm2/s), for 104 ≤ M ≤ 105. With the number‐averaged M values at one's disposal, the use of GPC may be circumvented in the calculation of the relation. From this and the deviation function several averages of M resulted, being reasonably in accordance with the GPC values. The ratio of radii, rη/rf, calculated from M, [η] and D, equals the value one very closely, but diminishes somewhat with M.
Thermodynamic Properties of n‐Butanol‐Cyclohexanone and N‐Butanol‐Ethylacetate Systems
Authors: Shanmugasundaram V. , Mohan R. 
Published: September 2010

AbstractThe temperature dependence of the equilibrium constants of n‐butanol‐cyclohexanone and n‐butanol‐ethylacetate systems has been studied by the dielectric method. The excess thermodynamic quantities of these systems are calculated and are used to point out the nature of interactions in these systems.
Synthesis in the Field of Natural Products of Biological Relevance
Authors: Arcamone Federico 
Published: September 2010

AbstractThe chemical manipulation of the aminosugar, daunosamine, has resulted in the development of new interesting doxorubicin analogues, namely 4′‐epi‐ and 4′‐deoxydoxorubicin, whereas the total synthesis of new aglycones has provided new structural types of the anthracyclines. In the field of beta‐lactams, efforts aimed to the discovery of original anti‐infective compounds have led to the synthesis of novel “penem” derivatives starting from methyl penicillinate.
Theoretical studies of localization phenomena in excited states of polyene chains
Authors: Brédas J. L. , Thémans B. , André J. M. , Piela L. 
Published: September 2010

AbstractWe present π‐electrons RHF‐SCF and CI calculations of the evolution of the first singlet excited state transition energy as a function of chain length, in polyene oligomers ranging from C2H4 up to C42H44. The results indicate that in small oligomers, the excitation is delocalized over the whole molecule. Localization phenomena are present in the larger chains (larger than ∼ C14H16) thereby explaining the failure of the RHF‐SCF technique to properly describe the first singlet excited state energies in the extended oligomers. Consequences in the use of so‐called OAO techniques are pointed out.
Synthesis of heterocycles from 3‐phenyl‐4‐tosylimino‐1, 3‐thiazetidine‐2‐thione
Authors: L'abbé Gerrit , Vangheluwe Patricia , Toppet Suzanne 
Published: September 2010

AbstractThe title compound 3 is transformed into the heterocycles 4‐7 by treatment with the reagents given in Scheme I. In all cases, initial nucleophilic attack occurs at the CS function of 3. The facile ring‐expansion reaction 3‐7 has been successfully extended to other 1,3‐thiazetidin‐2‐thiones (2, RPh, Tol) to give the corresponding 1, 2, 4‐dithiazolidine‐3‐thiones (13 and 14) in high yield.
3α‐Hydroxy‐8β‐Trinervita‐1,11‐Diene: A Novel Diterpene From TwoTrinervitermesSpecies
Authors: Braekman J. C. , Daloze D. , Dupont A. , Arrieta J. M. , Piccinni‐Leopardi C. , Germain G. , van Meerssche M. 
Published: September 2010

AbstractThis paper describes the structure determination of a novel diterpene, 3α‐hydroxy‐8β‐trinervita‐1,11‐diene, isolated from the defensive secretion of two West‐African termites:Trinervitermes oeconomusandT. trinervius.
On the Use of the Minimal STO‐3G Basis Set in Calculating The Geometries of Si Compounds
Authors: Roelandt F. F. , van De Vondel D. F. , van Der Kelen G. P. 
Published: September 2010

AbstractThe minimal STO‐3G basis set is applied to the ab initio calculation of the geometry of Si compounds. It is found that better results are obtained when scaling the ls H exponent scale factor to 1.06 instead of the usual value of 1.24. Changing the 3sp Si valence exponent seems to be less effective.
Large Ring Heterocycles: Template Synthesis and Structure
Authors: Shanzer Abraham 
Published: September 2010

AbstractOne of the major differences between synthetic and natural ion carriers is the abundance of amide and lactone groups in the natural compounds. In order to shed light on the role of the carbonyl groups in these molecules, several series of macrocyclic polycarbonyl compounds have been prepared, and their conformations compared with those of the naturally occurring ionophores. The synthesis of these compounds was achieved via the use of cyclic silicon and tin derivatives as templates. The conformation of the macrocyclic products was determined both in solution and in the solid state. This structural comparison led to recognize the effect of ring symmetry on conformation, and to realize that the presence of rotational symmetry is a prerequisite for a macrocyclic polycarbonyl compound to simulate the conformation of natural ionophores.
Spectres RMN‐1H et ‐13C de L'Acide Mercapto‐6 Pyridinecarboxylique‐2 et de Ses Dérivés Méthyles Correspondants
Authors: Gelbcke M. , Grimée R. , Lejeune R. , Thunus L. , Dejardin J. V. 
Published: September 2010

AbstractProton and carbon‐13 chemical shifts and coupling constants of 6‐mercapto‐2‐pyridinecarboxylic acid and its seven methylated derivatives are reported. Substituent effects are discussed
Separation, and characterization of the rotamers of hexakis (2‐methoxyphenyl) benzene and hexakis (2‐methylphenyl) benzene
Authors: Pepermans Henri , Gielen Marcel , Hoogzand Cornelis , Willem Rudolph 
Published: September 2010

AbstractThe HPLC separation and characterization of the rotamers of hexakis (2‐methoxy‐phenyl)benzene and hexakis (2‐methylphenyl) benzene are discussed. Preliminary results on the kinetics of the interconversion of the rotamers of hexakis (2‐methoxyphenyl) benzene are presented.
Triterpenoïdes de Harpullia Cupanioïdes
Authors: Dimbi Makoso Zeza , Warin Roger , Delaude Clément , Huls Robert , Mpuza Kapundu 
Published: September 2010

AbstractTree new triterpenoids have been isolated from acid hydrolyzate of the root bark saponin of Harpullia cupanioides Roxb.. Their structures have been established from spectral data as camelliagenin A 16‐tiglate, camelliagenin A l6‐β,β‐dimethylacrylate and camelliagenin A 22‐β, β‐dimethylacrylate.Besides these, other polyhydroxy triterpenoids characterized as camelliagenin A 22‐angelate, A1‐barrigenol 22‐angelate and A1‐barrigenol 22‐β, β‐dimethylacrylate have also been isolated.