Methyl-D-glucosamine-3, 6-dilauroyl, dimyristoyl, dipalmitoyl or distearoyl esters were synthesized as positively charged lipids. They were incorporated into phosphatidylcholine liposomal membranes and the entrapment of superoxide dismutase (SOD) into the liposomes was attempted. The efficiency of the SOD-entrapment into the positively charged multilamellar vesicles (MLVs), comprising egg yolk phosphatidylcholine and synthetic glucosamine diesters, was enhanced by the addition of cholesterol to the membranes. A differential scanning calorimetric study showed that the miscibility (solubility) of glucosamine diesters in phosphatidylcholine-bilayers increased on the addition of cholesterol to the membranes. Cholesterol assisted in the mixing of phosphatidylcholines with positively charged glucosamine diesters and increased the positive charges on the liposomal membranes. This was confirmed by incremental increases in the zeta-potential of liposomal membranes with an increase in the cholesterol content. Entrapment of SOD thus became more efficient due to the enhanced electrostatic attraction between the positvely charged membranes and the negatively charged SOD, and/or the electrostatic repulsive interactions between positiviely charged membranes; the latter interactions induced a thickening of the water layer in MLVs.

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The reaction of glycine (Gly) or L-α-alanine (Ala) with inorganic sodium cyclo-triphosphate hexahydrate (P_3m), Na₃P₃O₉·6H₂O gave dipeptides and the phosphorylated products of amino acids, but the reaction of L-valine (Val) or L-serine (Ser) with P_3m showed no peptide formation. The phosphorylated products of these reactions have a P-N bond in their molecules. Gly reacted with P_3m to give N-(carboxymethyl)phosphoramidate (P₁(N)Gly : 1a), 5-oxo-1, 3, 2-oxazaphospholidin-2-olate 2-oxide (P₁(N, O)Gly : 2a), which was a five-membered cyclic anhydride, N-(N-phosphonoglycyl)glycine (P₁-N(GlyGly) : 3a), N-(carboxymethyl)triphosphoramidate (P₃(N)Gly : 4a), and glycyl-glycine (GlyGly). A five-membered cyclic anhydride (2a) which was formed via an intramolecular cyclization of 4a was found to be a key intermediate for the production of GlyGly. Phosphorylation of Ala with P_3m also gave alanylalanine (AlaAla) in addition to the phosphorylated products including a five-membered cyclic anhydride. The yields of GlyGly and AlaAla were 15.8 and 2.0%, respectively. In the reactions of Val and Ser with P_3m, only N-(1-carboxy-2-methylpropyl)phosphoramidate (P₁-(N)Val : 1c) and N-(1-carboxy-2-hydroxyethyl)phosphoramidate (P₁-(N)Ser : 1d) were formed and their dipeptides were not obtained at all. The mechanism of the dipeptide formation will be discussed.

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Tricyclo[6.3.1.0^1.6]dodecane derivatives (5 and 6) corresponding to the B/C/D-ring systems of aphidicolane and stemodane diterpenes were synthesized stereoselectively via a spirodienone-alcohol (4) as a common intermediate. Participation of the neighboring hydroxyl group in 4 is crucial for controlling the stereochemistry of the spirocenters.

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Optically pure (R)-4, 4-diethoxy-2-(hydroxymethyl)butyl acetate (1) was synthesized enantioselectively by lipase-catalyzed transesterification from 4, 4-diethoxy-2-(hydroxymethyl)butanol. Coupling of silylated nucleobases and 2-O-acetyl-5-O-pivaloyl-(3S)-2, 3-dideoxyapiose (2) prepared from 1 was found to proceed smoothly in the presence of a catalytic amount of trimethylsilyl iodide under mild conditions to afford optically active nucleoside analogs.

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Various kinds of ethyl pyruvate 2-(2-substituted phenyl)hydrazones (1) were subjected to Fischer indolization with acid catalysts. All the phenylhydrazones gave corresponding normal 7-substituted indoles (2). In addition, phenyl-hydrazones whose ortho-substituent is electron-donative or has a central atom with an unshared electron pair tended to give the 4- or 5-substituted indole (3), which was produced by migration of the ortho-substituent during cyclization, whereas those whose ortho-substituent is electron-attractive tended to give little or no such abnormal product. The kind of acid catalyst used had some effect on the yield ratio of products but not on the kind of products.

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Reactive entities in the photoreaction of 2-, 3- and 4-iodopyridines with substituted benzenes were investigated; 3- and 4-pyridylation could be explained in terms of radical reaction, while the 2-pyridyl cation was an important intermediate in the 2-pyridylation. The importance of the unshared electron pair of the nitrogen adjacent to the radical carbon for the conversion of the 2-pyridyl radical initially produced into the cation is discussed on the basis of molecular orbital (MO) calculations.

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Two new ether-insoluble resin glycosides named woodrosins I and II were isolated from the stems of Ipomoea tuberosa L., and their structures were determined on the basis of chemical and spectral data. Contrary to anticipation, they had an intramolecular cyclic ester structure similar to that of ether-soluble resin glycosides (Mayer's jalapin) hitherto isolated.It is proposed to use the terms, "jalapin" and "convolvulin, " not according to the solubilily in ether (Mayer's classification), but according to the structure, i.e., intramolecular esters and others, respectively.

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Optically active β-lactams were synthesized by lipase-catalyzed kinetic resolution using the enantioselective hydrolysis of N-acyloxymethyl β-lactams (3) in an organic solvent and the transesterification of N-hydroxymethyl β-lactams (2) with vinyl acetate. A variety of highly optically pure β-lactams (2 and 3) possessing some substituents at the 3, 4, or both positions were obtained and the optically active N-hydroxymethyl β-lactams prepared were converted into useful N-unsubstituted ones without racemization.

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The ¹H- and ¹³C-NMR signals of eight triterpenoids belonging to the hopane and isohopane groups were completely assigned, and the conformations of their side chains are discussed on the basis of Chem3D Plus and MM2 calculations and nuclear Overhauser effect spectroscopy spectra.

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Some 2-pyridyl ketone hydrazones were subjected to aerial oxidation catalyzed by Cu²⁺. The oxidation product of di-2-pyridyl ketone hydrazone had the structure of a derivative of [1, 2, 3]-triazolo[1, 5-a]pyridine, and this structure is different from that previously proposed by other investigators. The fluorescence spectra of the oxidation products were measured in solutions of a wide pH range. In contrast to the oxidation products of other 2-pyridyl ketone hydrazones, that of di-2-pyridyl ketone hydrazone showed very strong fluorescence in acidic media. The characteristic nature of this compound was also apparent in the ultraviolet spectrum. The generation of hydroxyl radical was demonstrated in the aerial oxidation of di-2-pyridyl ketone hydrazone catalyzed by Cu²⁺, suggesting the formation of hydrogen peroxide as another oxidation product.

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From the less polar fraction of Chinese Alismatis Rhizoma [the dried rhizome of the aquatic plant Alisma orientale JUZEP. collected in Szechwan Province, China (Sentaku in Japanese)], three new protostane-type triterpenes named alisols E 23-acetate, F, and G were isolated together with four guaiane-type sesquiterpenes and several known triterpenes including 13, 17-epoxyalisol A. The absolute stereostructures of alisols E 23-acetate, F, and G have been determined on the basis of chemical and physicochemical evidence, which included the chemical correlations of alisols E 23-acetate, F, and G with the known triterpenes alisols A and A 24-acetate, and the application of the modified Mosher's method.

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A membrane-modifying peptide antibiotic having uncoupling activity on rat liver mitochondria, hypelcin A-III, has been synthesized by assembling five peptide fragments via the N, N'-dicyclohexylcarbodiimide method. The synthesized hypelcin A-III was identical with the natural product.

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The rearrangement of the angular methyl group in dehydroabietic acid derivatives was examined. Treatment of 12-methoxy-5, 8, 11, 13-abietatetraene (25) with boron trifluoride etherate afforded 12-methoxy-5β-methyl-10-norabieta-1(10), 8, 11, 13-tetraene (26). On the other hand, 12-methoxy-7-oxo-5, 8, 11, 13-abietatetraene (27) provided three naphthalene derivatives, 28, 29 and 30, on treatment with sulfuric acid in acetic anhydride. Methyl 7-oxo-5, 8, 11, 13-abietatetraen-18-oate (5) was reduced with sodium borohydride in the presence of cerium(III) chloride heptahydrate and the resulting alcohol (32) was further treated with p-toluensulfonic acid monohydrate to give methyl 5β-methyl-10-norabieta-1(10), 6, 8, 11, 13-pentaen-18-oate (33). On the other hand, under similar conditions, 7-oxo-5, 8, 11, 13-abietatetraene (11) and its 12-methoxy derivative (27) were transformed into the naphthalene derivatives, 35 and 37, respectively, via the corresponding alcohols, 34 and 36.

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Optically active lipopeptide derivatives have been synthesized by the use of chiral glycerol derivatives. Lipopeptide WS1279 derivatives with (R)-glycerol moieties showed a higher mitogenic activity than those with the (S)-configuration. Various N-protected lipopeptide and N-deprotected derivatives showed increased mitogenic activity.

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Some (piperidinomethylene)bis(phosphonic acid) derivatives were prepared and their activity to inhibit a rise in serum calcium induced by parathyroid hormone in thyroparathyroidectomised rats was evaluated. Several (4-alkylidene-, 4, 4-dialkyl-, or 4-alkyl-4-halopiperidinomethylene)bis(phosphonic acid) derivatives showed considerable inhibitory activity. But compounds having aromatic and polar substituents such as azido, hydroxy, amino and amido on the piperidine ring were generally inactive. In this study, two 4-alkylidene compounds (8a and 8b) and a 4, 4-cyclic dialkyl compound (61) showed potent activity when administered either intravenously or perorally.

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A series of N-[3-(5H-dibenzo[a, d]cyclohepten-5-ylidene)propyl]-N-methylamino- (6a) and N-[3-(6H-dibenz-[b, e]oxepin-11-ylidene)propyl]-N-methylamino-alkanoic acid derivatives (6b) and related compounds (6c-f) were synthesized and examined for pharmacological activities in vitro, i.e., inhibitory effect on monoamine [noradrenaline (NA) and 5-hydroxytryptamine (5-HT)] uptake, inhibitory effect on 5-HT-, histamine-, acetylcholine- and NA-induced contraction, and binding affinity for α₂-adrenoceptor and dopamine D₂-receptor. In vitro tests indicated that zwitter-ionization was capable of maintaining H₁-antihistaminic activity while greatly reducing other pharmacological activities. Further, 6a-f showed much stonger inhibitory effects on compound 48/80-induced lethality in rats than did the corresponding N, N-dimethylamines (2a-f). 3-[N-[3-(6H-Dibenz[b, e]oxepin-11-ylidene)propyl]-N-methylamino]-propionic acid (6b-2), selected as a candidate antiallergic agent of a new type, equally potent in rats and guinea-pigs, exhibited strong inhibitory effects on 48 h homologous passive cutaneous anaphylaxis (PCA) in rats (ED₅₀=0.019 mg/kg, p.o.) and on histamine-induced bronchoconstriction in anesthetized guinea-pigs (ED₅₀=0.0067 mg/kg, p.o.).

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A new radioligand for monoamine oxidase type A (MAO-A), [¹¹C]fluoroclorgyline, was synthesized from its desmethyl precursor by N-methylation reaction using [¹¹C]methyl iodide with a radiochemical yield of 75-85%. The radiochemical purity of the product was more than 99% and the specific radioactivity was 7.4-18.5 GBq/μmol. The in vivo tissue distribution studies of [¹¹C]fluoroclorgyline in mice demonstrated its high initial uptake and prolonged retention in the brain, comparable to those of [¹¹C]clorgyline. A selective interaction with MAO-A in the accumulation of [¹¹C]fluoroclorgyline was confirmed by a competition experiment performed with the MAO-A specific inhibitor, clorgyline, and MAO-B specific inhibitor, l-deprenyl. These very desirable characteristics of [¹¹] fluoroclorgyline suggested that its ¹⁸F labeled counterpart, [¹⁸F]fluoroclorgyline, would have great potential as a longer-lived alternative to ¹¹C labeled clorgyline for in vivo studies of MAO-A in the human brain with positron emission tomography (PET).

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A formulation of meropenem, a novel carbapenem antibiotic for injection, was developed as a vial filled with a mixture of meropenem and dried sodium carbonate. During the design phase, we studied the effect of water in the formulation on the stability of meropenem in the solid state.Meropenem is obtained as trihydrate, whose moisture content is 12.35% and is nonhygroscopic. Dehydrated meropenem, whose moisture content was 3.4%, took up moisture quickly even under low humidity (33% RH). Also, the chemical stability of dehydrated meropenem was poor compared with that of untreated meropenem, which is quite stable. Degradation of meropenem by free water was considered as a possible cause of the poor stability. Degradation of meropenem due to liberation of its crystal water to free water was also observed when meropenem was micronized by pneumatic pulverization.Crystal water of meropenem was found to stay bound and to be almost inert in the formulation. Thus, meropenem injection formulation is stable for long time at room temperature.

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We have synthesized 3-(o, m or p-substituted benzylidene)isoindolinone and 3-(2-o, m or p-substituted phenylethylidene)isoindolinone, which possess inhibitory activity for thromboxane A₂ analog (U-46619)-induced vasoconstriction.

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The following substances were identified in the fresh leaves and branches of Prunus zippeliana MIQ. : 22-dehydroclerosteryl acetate, stigmasteryl acetate, β-sitosterol, stigmasterol, clerosterol, 22-dehydroclerosterol, β-sitosterol and stigmasterol 3-O-β-D-glucopyranoside, ursolic acid, oleanolic acid, 2α-hydroxyursolic acid, tormentic acid, methyl linolate, phytol, prunasin, dl-mandelic acid, kaempferol 3-O-[O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside] and d-mandelic acid β-D-glucopyranoside.Worthy of note is that 24α-ethylsterols (β-sitosterol and stigmasterol) and 24β-ethylsterols (clerosterol and 22-dehydroclerosterol) were obtained together from the leaves of a higher plant.

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From rhizomes and roots of Panax vietnamensis HA et GRUSHV., Araliaceae, commonly known as Vietnamese Ginseng, two new acetylated saponins named vina-ginsenoside-R1 (13) and vina-ginsenoside-R2 (15) were isolated. On the basis of chemical and spectral data, 13 was formulated as monoacetyl 24(S)-pseudo-ginsenoside-F₁₁ and 15 was proved to be monoacetyl majonoside-R2.Besides the two new saponins and β-sitosteryl-3-O-β-D-glucopyranoside, sixteen known saponins were also isolated and identified. Dammarane saponins : ginsenoside-Rh₁ and 20(R)-ginsenoside-Rh₁ (1), ginsenosides-Rg₁ (2), -Re (3), -Rd(6), -Rb₃ (7), -Rb₂ (8), -Rb₁ (9), pseudo-ginsenoside-RS₁ (=monoacetyl ginsenoside-Re, 4), notoginsenosides-R1 (5) and -Fa (10). Ocotillol-type saponins : pseudo-ginsenoside-RT₄ (11), 24(S)-pseudo-ginsenoside-F₁₁ (12), majonosides-R1 (16) and -R2 (14). Oleanolic acid saponins : ginsenoside-Ro (=chikusetsusaponin V, 17) and hemsloside-Ma3 (18), a saponin previously isolated from a cucurbitaceous plant, Hemsleya macrosperma C. Y. WU.Despite having large horizontally elongated rhizomes, the underground part of this plant contains mainly dammarane saponins and a small amount of oleanolic acid saponins. In addition, the yield of ocotillol-type saponins, especially majonoside-R2, is surprisingly very high (more than 5% and ca. half of the total yield of saponin). This characteristic saponin composition has made Vietnamese Ginseng an interesting species among Panax spp.

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Two enzyme reactions involved in the post-aromatic deoxygenation process of fungal melanin and pigments were studied from the viewpoint of enzymic reduction of aromatic rings. Hydroxynaphthalene reductase that catalyzes reduction of the aromatic rings of 1, 3, 6, 8-tetrahydroxynaphthalene and 1, 3, 8-trihydroxynapthalene was partially purified from Phialophora lagerbergii and characterized. Emodin deoxygenase of Pyrenochaeta terrestris that catalyzes deoxygenation of emodin to afford chrysophanol was found to be resolved into two protein fractions with DEAE-cellulose column. The two protein fractions acted synergistically in regard to emodin deoxygenase activity.

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Molecular interactions between spin probe reagents and β-cyclodextrin (β-CyD) in ethanol were investigated on the basis of the rotational correlation time of the spin probes as estimated by the ESR spectrum simulation. The effect of the functional groups of spin probes, possibly hydrogen-bonding interactions, on the hydroxylated surface of the β-CyD molecule were suggested from the thermodynamic data on the rotational correlation times, which could be combined with the rotational mobilities of spin probes confined in a microscopic liquid phase.

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The association of saturated fatty acid (FA) with carbon number (n) of 12-18 has been investigated in 1, 2-dichloroethane by measuring the fluorescence spectrum and intensity of ammonium 8-anilino-1-naphthalenesulfonate as a fluorescent probe at 25, 40, 50 and 60°C, and the effects of n and temperature on the association of FA were also studied. A simple phase diagram of octadecanoic acid in 1, 2-dichloroethane was constructed.The critical concentration at which the dimers or the trimers of FA began to appear, C₁, was approximately the same for all cases; C₁ did not depend on n or temperature. On the contrary, the critical concentration at which the reversed micelles of FA were formed, C₂, decreased regularly as n increased. The relationship between log C₂ vs. n thus indicated a linearity.

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Cyclic octapeptides, cyclo[L-Tyr(Bzl)-L-Pro]₄ (2) and cyclo(L-Tyr-L-Pro)₄ (3), were prepared and their conformations investigated. A C₂-symmetric conformation containing two cis peptide bonds was found in 2 in CDCl₃ and 3 in CD₃OD. Cyclo(L-Phe-L-Pro)₄ (1) formed a 1 : 1 complex with L-phenylalanine methylester hydrochloride (L-PheOMe·HCl). The ¹³C-NMR spectra of the complexes of 1 and 2 with 1 eq of D- and L-PheOMe·HCl (D/L ratio=1/2) in CDCl₃ displayed separate resonances for several carbon atoms of D-PheOMe·HCl and L-PheOMe·HCl owing to the formation of diastereomeric pairs of the complexes.

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The structure 1a proposed for flavidulol A, which was isolated from the mushroom Lactarius flavidulus IMAI, was revised to 1b based upon comparison with a synthetic specimen, as well as a difference nuclear Overhauser effect (NOE) experiment. As a consequence, the structures of flavidulols B (2a) and C (3a) were also revised to 2b and 3b, respectively. Flavidulol D (4) was newly isolated from the same mushroom, and its structure was elucidated as flavidulol A stearate on the basis of spectroscopic data.

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(6S, 7S)-1-Oxa-7-bromomethylspiro[5.5]undecanes (12 and 13) were synthesized from the optically active alkenyl sulfoxide (7). The key step involves a tandem regioselective cleavage of cyclopropane ring and stereoselective nucleophilic cyclization of the cyclopropylcarboxylic acid (11).

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Boc-Tyr-Gly-Gly-Phe-Leu-CH₂Cl was synthesized by the conventional solution method. During the course of acid hydrolysis (6N HCl, 110°C, 18 h) of Boc-Phe-Leu-CH₂Cl, side reaction occurred, resulting in low recovery of Phe residue on amino acid analysis. The inhibitory activity of the synthesized Boc-Tyr-Gly-Gly-Phe-Leu-CH₂-Cl against endopeptidase 22.19, an enzyme related to the metabolism of opioid peptides, was examined.

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A new azaphilone derivative, falconensin H (6), was isolated from mycelia of Emericella falconensis, together with previously reported falconensins A-D (1-4) and 3, 3'-dihydroxy-5, 5'-dimethyldiphenyl ether (5). The structure of 6 was elucidated by spectroscopic investigation and chemical correlations. Among the compounds isolated, only 5 showed antibacterial activity.

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Aliphatic and aromatic acetals are easily and efficiently converted to the corresponding nitriles by reaction with hydroxylamine hydrochloride in refluxing absolute ethanol.

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Optically active 4-ethyl-3, 5-dihydroxy-2-methylpentyl derivatives, the iodide (4), phenyl sulfone (5), and phenyl sulfoxide (6), which are chiral synthons for an essential structural unit of polyether antibiotics, were stereoselectively synthesized starting from commercially available methyl (2S)-3-hydroxy-2-methylpropionate (7) in good overall yield (33% for 18 steps).

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A general synthetic route to 7-alkyl-1-methyladenine (8) from N⁶-methoxy-1-methyladenosine (5) in three steps [hence from adenosine (1) in seven steps] has been established. The route started with alkylation of 5, readily obtainable from 1 in four steps according to previously reported procedures, and proceeded through glycosidic methanolysis of the resulting 7-alkylated nucleoside (6) and removal of the N⁶-methoxy group by catalytic hydrogenolysis.

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We synthesized putative metabolites of 4'-acetyl-2'-(2, 4-difluorophenoxy)methanesulfonanilide (FK3311, 1), a novel antiinflammatory agent, in order to confirm their structures and also to investigate their pharmacological properties. The structuers of the metabolites 2-5 were confirmed by direct comparison with the synthesized authentic compounds. We employed the following tests to assess pharmacological activities : zymosan-induced prostaglandin E₂ production for in vitro activity, adjuvant-induced arthritis for antiinflammatory activity, and acetic acid-induced writhing for analgesic activity. Metabolite 2 is nearly equipotent to 1 in the in vivo tests and metabolite 3 is an active metabolite with in vitro activity comparable to that of 1.

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The poly(ethylene glycol) hybrid of Leu-enkephalin (Tyr-Gly-Gly-Phe-Leu) was prepared and its analgesic activity was examined. Poly(ethylene glycol) #4000 was converted to amino-poly(ethylene glycol) and coupled with the N^α-protected pentapeptide, followed by trifluoroacetic acid treatment to give the hybrid. The hybrid was soluble in water or various organic solvents. The analgesic activity of Leu-enkephalin was markedly potentiated by hybrid formation with poly(ethylene glycol).

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The resistance to crushing after a self-setting bioactive calcium phosphate cement, consisting of various particle sizes of tetracalcium phosphate (TECP), dicalcium phosphate dihydrate (DCPD) and hydroxyapatite (HAP), had hardened was tested after setting at 37°C, 100% RH. X-ray diffraction suggested that the cement containing fine particles of DCPD and TECP was completely transformed to HAP, but that containing larger particles was not. Since particle size of both DCPD and TECP affected the dissolution rate, the crystal growth of HAP during cement formation depended on the specific surface area (Sw) of the raw materials. The crushing strength of the cement after hardening increased with an increase of its Sw.

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Octasaccharide corresponding to the partial structure derived from lipid IV has been prepared by coupling of the nonreducing end trisaccharide with reducing end pentasaccharide as an acceptor in the presence of dimethyl(methylthio)sulfonium triflate, followed by deprotection of a desirable protected octasaccharide.

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The chemical structure of claudimerin-A (1), a novel dimeric coumarin from roots of Citrus hassaku (Rutaceae), have been elucidated by spectrometric studies and a single crystal X-ray analysis. The structure of 1 consisted of two clausarin (2) units linked symmetrically with the forming of the pyranopyran ring.

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Renaturation of subtilisin BPN' could successfully be attained in the case of subtilisin immobilized covalently on an agarose gel in the medium containing 2 M potassium acetate or other salts. The maximum yield of renaturation based on enzymatic activity was as high as 80% in the presence of 2 M potassium acetate from the fully denatured immobilized subtilisin. Preliminary denaturation in 6 M guanidine hydrochloride at pH 2.4 for 4 h rendered 20-30% of immobilized subtilisin to release from the agarose gel, which was estimated by reverse-phase high performance liquid chromatography as well as by electrophoresis. We concluded that, in the presence of 2 M potassium acetate, we could achieve almost quantitative refolding of subtilisin by immobilization.Next, the rate of renaturation of denatured immobilized subtilisin was compared among several media containing several salts at the concentration of 2 M, at 25°C. The times for 50% renaturation t<1/2>'s, in the presence of potassium acetate, potassium chloride, and lithium chloride were about 24, 63, and 153 min with apparent ultimate yields of 80, 71, and 40%, respectively. Higher rates and yields resulted also in the presence of the other organic salts such as dipotassium succinate and potassium propionate.

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The aggregation form of mixtures of phosphatidylcholine and MDP derivatives was studied. The mixed vesicles containing less than 40 % of B30-MDP were unilamellar, and over 40 % B30-MDP aggregates of mixed vesicles or oligolammellar vesicles appeared. The mixed vesicles containing less than 20 % of DV-7401 were unilamellar, and over 20 % of it fibriform structures appeared.

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By monitoring the inhibitory effect on ethanol absorption in rats, new active saponins named elatosides A and B were isolated from the bark of Aralia elata SEEM. together with elatosides C and D. The structures of elatosides A, B, C, and D were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effects of several oleanolic acid oligoglycosides on ethanol absorption have been examined and some structure-activity relationships have been found.

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