Showing papers in "Chemical & Pharmaceutical Bulletin in 1997"
TL;DR: The biotransformation of (-)-epicatechin 3-O-gallate and related compounds was undertaken using a human fecal suspension, suggesting a difference in metabolic ability between two intestinal bacterial mixtures from different species.
Abstract: The biotransformation of (-)-epicatechin 3-O-gallate (1) and related compounds was undertaken using a human fecal suspension. Of fifteen metabolites isolated, four compounds were new, namely, two epimers of 1-(3'-hydroxyphenyl)-3-(2",4".6"-trihydroxyphenyl)propan-2-ols (6, 19); 2",3"-dihydroxyphenoxyl 3-(3',4'-dihydroxyphenyl)propionate (14) and 1-(3',4'-dihydroxyphenyl)-3-(2",4",6"-trihydroxyphenyl)propan-2-ol (18). (-)-Epicatechin (2), (-)-epigallocatechin (16) and their 3-O-gallates (1, 17) were extensively metabolized by a human fecal suspension after incubation for 24 h, whereas the gallates (1, 17) resisted any degradation by a rat fecal suspension, even after a prolonged incubation time (48 h), suggesting a difference in metabolic ability between two intestinal bacterial mixtures from different species.
178 citations
TL;DR: Six new furostanol saponins called trigoneosides Ia, Ib, IIa, IIb, IIIa, and IIIb were isolated from a medicinal foodstuff, fenugreek seed, the seed of Trigonella foenum-graecum L.
Abstract: Six new furostanol saponins called trigoneosides Ia, Ib, IIa, IIb, IIIa, and IIIb were isolated from a medicinal foodstuff, fenugreek seed, the seed of Trigonella foenum-graecum L. (Leguminosae) originating from India, together with two known saponins, glycoside D and trigofoenoside A. The structures of trigoneosides Ia, Ib, IIa, IIb, IIIa, and IIIb were determined on the basis of chemical and physicochemical evidence as 26-O-beta-D-glucopyranosyl-(25S)-5 alpha-furostane-2 alpha,3 beta,22 zeta,26-tetraol 3-O-[beta-D-xylopyranosyl (1 --> 6)]-beta-D-glucopyranoside, 26-O-beta-D-glucopyranosyl-(25R)- 5 alpha-furostane-2 alpha,3 beta,22 zeta,26-tetraol 3-O-[beta-D-xylopyranosyl (1-->6)]-beta-D-glucopyranoside, 26-O-beta-D-glucopyranosyl-(25R)-5 beta-furostane-3 beta,22 zeta,26-triol 3-O-[beta-D-xylopyranosyl (1 --> 6)]-beta-D-glucopyranoside, 26-O-beta-D-glucopyranosyl-(25R)-5 beta-furostane-3 beta,22 zeta,26-triol 3-O-[beta-D-xylopyranosyl (1-->6)]-beta-D-glucopyranoside, 26-O-beta-D-glucopyranosyl-(25S)-5 alpha-furostane-3 beta,22 zeta,26-triol 3-O-[alpha-L-rhamnopyranosyl(1 --> 2)]-beta-D-glucopyranoside, and 26-O-beta-D-glucopyranosyl-(25R)-5 alpha-furostane-3 beta,22 zeta,26-triol 3-O-[alpha-L-rhamnopyranosyl (1 --> 2)]-beta-D-glucopyranoside, respectively.
153 citations
TL;DR: Seven antioxidative serotonin derivatives were isolated from safflower (Carthamus tinctorius L.) oil cake and compounds 1-5 were found to have relatively strong antioxidative activity.
Abstract: Seven antioxidative serotonin derivatives were isolated from safflower (Carthamus tinctorius L.) oil cake. Their structures were established as N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]ferulamide (1), N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]-p-coumaramide (2), N, N'-[2, 2'-(5, 5'-dihydroxy-4, 4'-bi-1H-indol-3, 3'-yl)diethyl]-di-p-coumaramide (3, ) N-[2-[3'-[2-(p-coumaramido)ethyl]-5, 5'-dihydroxy-4, 4'-bi-1H-indol-3-yl]ethyl]ferulamide (4), and N, N'-[2, 2'-(5, 5'-dihydroxy-4, 4'-bi-1H-indol-3, 3'-yl)diethyl]-diferulamide (5), N-[2-[5-(β-D-glucosyloxy)-1H-indol-3-yl]ethyl]-p-coumaramide (6), and N-[2-[5-(β-D-glucosyloxy)-1H-indol-3-yl]ethyl]ferulamide (7). Antioxidative activities of the compounds were measured by the ferric thiocyanate method and the α, α-diphenyl-β-picrylhydrazyl (DPPH) method, and compounds 1-5 were found to have relatively strong antioxidative activity.
139 citations
TL;DR: Three new ionone glucosides named corchoionosides A, B, and C were isolated from the leaves of Corchorus olitorius and were found to inhibit the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.
Abstract: Three new ionone glucosides named corchoionosides A, B, and C were isolated from the leaves of Corchorus olitorius, commonly called "moroheiya" in Japanese, together with seven known compounds, an ionone glucoside (6S,9R)-roseoside, a monoterpene glucoside betulalbuside A, two flavonol glucosides astragalin and isoquercitrin, two coumarin glucosides scopolin and cichoriine, and chlorogenic acid. The absolute stereostructures of corchoionosides A, B, and C were determined by chemical and physiochemical evidence, which included the result of application of a modified Mosher's method, the CD helicity rule, and chemical correlation with (6S,9R)-roseoside. Corchoionosides A and B and (6S,9R)-roseoside were found to inhibit the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.
125 citations
TL;DR: In this article, the structures of these compounds were elucidated on the basis of spectral data, and four new sterols, 5α, 6α-epoxy-(22E, 24R)-ergosta-8(14), 22-diene-3β, 7β-diol (1), 6β-tetrol (2), 3β-5α-6β-trihydroxy (3β)-ergost-22-en-7-one (4), have been isolated from the fruit bodies of Grifola frondosa
Abstract: Four new sterols, 5α, 6α-epoxy-(22E, 24R)-ergosta-8(14), 22-diene-3β, 7β-diol (1), (22E, 24R)-ergosta-8, 22-diene-3β, 5α, 6β, 7α-tetrol (2), (22E, 24R)-ergosta-7, 9(11), 22-triene-3β, 5α, 6β-triol (3) and 3β, 5α, 6β-trihydroxy-(22E, 24R)-ergost-22-en-7-one (4), have been isolated from the fruit bodies of Grifola frondosa (FR.) S. F. GRAY (Polyporaceae)together with fourteen known ones (5-18), of which two (5 and 6) are reported for the first time from a natural source. The structures of these compounds were elucidated on the basis of spectral data.
109 citations
TL;DR: The glycosidic fraction from the dried roots of Panax notoginseng (Burk.) F.H. Chen was found to show protective effect on liver injury induced by D-galactosamine and lipopolysaccharide.
Abstract: The glycosidic fraction from the dried roots of Panax notoginseng (Burk.) F.H. Chen was found to show protective effect on liver injury induced by D-galactosamine and lipopolysaccharide. From the glycosidic fraction with hepatoprotective effect, nine new dammarane-type triterpene oligoglycosides, notoginsenosides-A, -B, -C, -D, -E, -G, -H, -I, and -J and an acetylenic fatty acid glycoside, notoginsenic acid beta-sophoroside, were isolated together with fourteen known dammarane-type triterpene oligoglycosides. The structures of notoginsenosides-A, -B, -C and -D were determined on the basis of chemical and physicochemical evidence, which included the chemical correlation with ginsenoside-Rb1 using photosensitized oxygenation, as follows: notoginsenoside A; 3-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 3 beta, 12 beta,20(S),25-tetrahydroxydammar -23-ene; B; 3-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-glucopyranosyl (1-->6)-beta-D- glucopyranosyl] 3 beta, 12 beta,20(S)-trihydroxydammar-25-en-24-one, C; 3-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D -glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 3 beta,12 beta,20(S)- trihydroxy-24 zeta-hydroperoxydammar-25-ene, and D; 3-O-[beta-D-xylopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl]20(S)-protopanaxadiol, respectively.
103 citations
TL;DR: N-Aryl heterocyclic compounds were synthesized from aryl halides and heterocycling compounds containing an -NHCO- moiety by using a catalytic amount (1-10mol%) of a commercially available copper catalyst in satisfactory yields.
Abstract: N-Aryl heterocyclic compounds were synthesized from aryl halides and heterocyclic compounds containing an -NHCO- moiety by using a catalytic amount (1-10mol%) of a commercially available copper catalyst in satisfactory yields. This catalytic reaction was applicable to the synthesis of N-aryl-2-pyridone, -2-pyrrolidone, -1(2H)-isoquinolone, -1(2H)-phthalazinone, -4(3H)-quinazolinone and -1,2,3-benzotriazin-4(3H)-one derivatives.
93 citations
TL;DR: Skin penetration of methyl, ethyl, propyl and butyl parabens through excised guinea pig dorsal skin was examined, and effects of the penetration enhancers, l-menthol plus ethanol itself and N-dodecyl-2-pyrrolidone, were observed, and dependency of the permeability coefficients of the paraben on n-octanol/water partition coefficients almost disappeared in the presence of this compound.
Abstract: Skin penetration of methyl, ethyl, propyl and butyl parabens through excised guinea pig dorsal skin was examined, and effects of the penetration enhancers, l-menthol plus ethanol itself and N-dodecyl-2-pyrrolidone, were observed. Permeability of coefficients of the parabens correlated with n-octanol/water partition coefficients. Addition of 1% l-menthol in 15% ethanol about sixteen times increased the permeability coefficient of methyl paraben, whereas this enhancer decreased that of butyl paraben to about one fifth of the control value. A similar, though weaker, tendency was observed for the effects of 15% ethanol itself. 0.025% suspension of N-dodecyl-2-pyrrolidone increased the permeability coefficient of methyl paraben about seven times, whereas it did not change that of butyl paraben significantly. Therefore, dependency of the permeability coefficients of the parabens on n-octanol/water partition coefficients almost disappeared in the presence of this compound. A spin label study with stratum corneum lipid liposomes revealed that increase of fluidity of the lipid bilayer by these penetration enhancers corresponded with their enhancement effects on skin penetration of methyl paraben. Perturbation of stratum corneum lipid lamella thus seems to be related with their enhancement of the absorption of hydrophilic paraben.
78 citations
TL;DR: Garsubellin A (1), a novel polyprenylated phloroglucin derivative, has been isolated from the wood of Garcinia subelliptica and its structure has been elucidated by spectroscopic analyses.
Abstract: Garsubellin A (1), a novel polyprenylated phloroglucin derivative, has been isolated from the wood of Garcinia subelliptica and its structure has been elucidated by spectroscopic analyses. Compound 1 could increase the ChAT activity at 10 microM in P10 rat septal neuron cultures.
77 citations
TL;DR: Gymnemoside b and gymnemic acids III, V, and VII were found to exhibit a little inhibitory activity against glucose absorption, but the principal constituents, gymnemic acid I and gymnemasaponin V, lacked this activity.
Abstract: Although the glycosidic fraction from the dried leaves of Gymnema sylvestre R. BR., gymnemic acid, was reported to be effective for diabetes, it showed little inhibitory activity on the increase of serum glucose level in oral glucose-loaded rats. From the glycosidic fraction, six triterpene glycosides, gymnemosides a, b, c, d, e, and f, were isolated together with nine known triterpene glycosides. The structures of gymnemosides a and b were determined on the basis of chemical and physicochemical evidence as 21-O-tigloyl-22-O-acetylgymnemagenin 3-O-beta-D-glucopyranosiduronic acid and 16-O-acetyl-21-O-tigloylgymnemagenin 3-O-beta-D-glucopyranosiduronic acid, respectively. In addition, an acetyl group linked to the 16- or 22-hydroxyl group in gymnemosides a and b was found to migrate easily to the primary 28-hydroxyl group, while the acyl migration from the 28-position was rarely observed. The inhibitory activity of each triterpene glycoside from gymnemic acid was examined to determine its impact on the increase of serum glucose level in oral glucose-loaded rats. Gymnemoside b and gymnemic acids III, V, and VII were found to exhibit a little inhibitory activity against glucose absorption, but the principal constituents, gymnemic acid I and gymnemasaponin V, lacked this activity.
77 citations
TL;DR: For the nicotinamide-HPMC system, the supersaturation level of nifedipine increased with an increase in the HPMC content of solid dispersions, and Nicotinamide was more applicable than ethylurea and PEG for preparation of the fused dispersions of n ifedipines.
Abstract: The most prevalent means for producing solid dispersions of nifedipine, a poorly water-soluble drug, are the solvent based processes that bring problems of environmental and health. We have investigated the preparation of solid dispersions of nifedipine (mp 173°C) by the fusion method, using nicotinamide, ethylurea, polyethylene glycol (PEG) 6000 and hydroxypropylmethylcellulose (HPMC) as carriers. All these solid dispersions were obtained by cooling at room temperature after heating at 140°C for 15 min. As a single carrier, nicotinamide, ethylurea and PEG were used because nifedipine dissolved in their fused liquids. Compared with the physical mixtures, the solid dispersions with ethylurea or PEG led to a higher dissolution rate of the drug, whereas the difference in drug release between the physical mixtures and the solid dispersions with nicotinamide was not clear. This peculiarity might be due to the high solubilizing effect of nicotinamide for the drug. The fused mixtures of nicotinamide-, ethylurea- or PEG-HPMC were utilized as combined carriers. HPMC dissolved in the fused liquids of nicotinamide or ethylurea, which was effective in forming the amorphous nifedipine in solid dispersions. This resulted in not only the enhanced dissolution rate but also the supersaturation behavior of nifedipine. Further, for the nicotinamide-HPMC system, the supersaturation level of nifedipine increased with an increase in the HPMC content of solid dispersions. Nicotinamide was more applicable than ethylurea and PEG for preparation of the fused dispersions of nifedipine.
TL;DR: Acteoside (verbascoside) was isolated as an analgesic principle from Cedron (leaves and stem of Lippia triphylla (L'HER) O. KUNTZE; Verbenaceae), a Peruvian medicinal plant, by activity-guided separation.
Abstract: Acteoside (verbascoside) was isolated as an analgesic principle from Cedron (leaves and stem of Lippia triphylla (L'HER) O. KUNTZE; Verbenaceae), a Peruvian medicinal plant, by activity-guided separation. The compound exhibited analgesia on acetic acid-induced writhing and on tail pressure pain in mice by the oral administration of 300 mg/kg and 100 mg/kg, respectively. Acteoside also caused weak sedation by its effect on the prolongation of pentobarbital-induced anesthesia and on the depression of locomotion enhanced by methamphetamine. An intravenous injection of acteoside reduced the effective dose to 2 mg/kg by the writhing method. Thirteen related compounds were tested for the activity by intravenous and oral administration to obtain information on the active structure.
TL;DR: Several 2',2'-difluorodocetaxel derivatives were prepared and evaluated their cytotoxicity against mouse leukemia and human tumor cell lines and their microtubule disassembly-inhibitory activity.
Abstract: To investigate the role of the 2'-hydroxy group at the C-13 side chain of docetaxel in the antitumor activity, we prepared several 2',2'-difluoro derivatives of docetaxel and evaluated their cytotoxicity against mouse leukemia and human tumor cell lines and their microtubule disassembly-inhibitory activity. These analogues were prepared by esterification of protected 10-deacetylbaccatin III (21) with appropriate alpha, alpha-difluorinated carboxylic acids (Charts 1 and 2). Among these 2',2'-difluorodocetaxel derivatives, 2',2'-difluorodocetaxel (23b) was approximately 3-10 times as active as 2'-fluorodocetaxel (29a) in terms of cytotoxicity. In addition, the 3'-(2-furyl) (23h) and 3'-(2-pyrrolyl) (23p) analogues showed activity comparable or superior to that of docetaxel (2).
TL;DR: A naphthoquinone called elecanacin (9) and a new naphthalene called isoeleutherol (10) were isolated from the bulb of Eleutherine americana MERR..
Abstract: A novel new naphthoquinone called elecanacin (9) and a new naphthalene called isoeleutherol (10) were isolated from the bulb of Eleutherine americana MERR. et HEYNE (Iridaceae), together with two known naphthoquinones (2 and 3). The structures were determined by spectroscopic methods including the 2D-NMR techniques. Eleutherin (2) showed interesting inhibitory activity against human topoisomerase II, and isoeleutherin (3) and isoeleutherol (10) showed inhibitory activity against HIV.
TL;DR: In this article, Clausena excavata BURM (Rutaceae) roots, the stem bark, and the leaves of the tree were studied and new carbazole alkaloids named clauszoline-H (1), -I (2), and -J (4) from the roots were isolated, together with known carbazoles and coumarins.
Abstract: Constituents of the roots, the stem bark, and the leaves of Clausena excavata BURM. f. (Rutaceae) grown in a greenhouse at Okitsu Branch, Fruit Tree Research Station, Shizuoka, were studied. New carbazole alkaloids named clauszoline-H (1), -I (2), and -J (4) from the roots, clauszoline-K (6) and -L (7) from the stem bark, and clauszoline-M (8) from the leaves were isolated, together with known carbazoles and coumarins, and their structures were elucidated by spectroscopic methods.
TL;DR: Six new pyrrolidine alkaloids were isolated from the branches of Broussonetia kazinoki Sieb.
Abstract: Six new pyrrolidine alkaloids called broussonetine A, B, E, F, and broussonetinine A and B were isolated from the branches of Broussonetia kazinoki SIEB. (Moraceae). Broussonetine A, B, E and F were formulated as 2β-hydroxymethyl-3β-hydroxy-5α-(10-oxo-13-hydroxytridecyl)-pyrrolidine-4-O-β-D-glucopyranoside (1), 2β-hydroxymethyl-3β-hydroxy-5α-(9-oxo-13-hydroxytridecyl)-pyrrolidine-4-O-β-D-glucopyranoside (2), 2β-hydroxymethyl-3α, 4β-dihydroxy-5α-(1, 13-dihydroxy-10-oxo-tridecyl)-pyrrolidine (3), and 2β-hydroxymethyl-3α, 4β-dihydroxy-5α-(1, 13-dihydroxy-9-oxo-tridecyl)-pyrrolidine (4), respectively. Broussonetinine A and B (5 and 6) were also isolated and identified as the aglycones of 1 and 2. 3 and 4 exhibited a strong inhibition of α-glucosidase, β-glucosidase, β-galactosidase and β-mannosidase, while 5 and 6 showed a strong inhibition of β-galactosidase and α-mannosidase.
TL;DR: A series of novel 1,5-diarylpyrazole derivatives was synthesized and tested for anti-inflammatory and analgesic activities to develop anti- inflammatory agents with fewer side effects than existing nonsteroidal anti- inflammation drugs.
Abstract: A series of novel 1,5-diarylpyrazole derivatives was synthesized and tested for anti-inflammatory and analgesic activities to develop anti-inflammatory agents with fewer side effects than existing nonsteroidal anti-inflammatory drugs. The structure-activity relationships in this series were extensively studied. Electron-withdrawing substituents such as CN and CF3 were optimal at the 3-position of the pyrazole ring. Replacement of these substituents with bulky ones gave less active compounds. The 4-(methylsulfonyl)phenyl group seemed to be the optimal group at the 5-position of the pyrazole ring. The most potent compound was 1-(4-fluorophenyl)-5-[4-(methylsulfonyl)phenyl]-pyrazole-3-carbonitrile (19a), with oral ED50 value of 0.030 and 0.47 mg/kg on adjuvant-induced arthritis and collagen-induced arthritis, respectively, and an ED30 value of 7.4 mg/kg in the yeast-induced hyperalgesia (Randall-Selitto) assay. Compound 19a also showed potent inducible cyclooxygenase (COX-2)-inhibitory activity (IC50 = 0.24 microM) with no COX-1 inhibition even at 100 microM.
TL;DR: It was concluded that tanshinone IIA (6) is the major active constituent of the MeOH extract and danshenol A (I) and (-)danshexinkun A(7) are the minor ones.
Abstract: The constituents of the MeOH extract of Salvia miltiorhiza BUNGE, which showed strong aldose reductase (AR) inhibitory activity, were examined, and two new abietane-type diterpenoids, danshenol A (1) and danshenol B (2), were isolated together with six known ones: dihydrotanshimme I (3), cryptotanshinone (4), tanshinone I (5), tanshinone IIA (6), (-)-danshexinkun A (7), and sugiol (8). Among them, 4, 5, and 8 were weak AR inhibitors with IC50 from 4.80 to > 10.0 microM, while 1, 2, 3, 6, and 7 were strong inhibitors (IC50 from 0.10 to 1.75 microM). Danshenol A (1), the strongest inhibitor, had IC50 of 0.10 microM which is comparable to that of epalrestat in clinical use. Moreover, from a consideration of IC50, and yield of each compound, it was concluded that tanshinone IIA (6) is the major active constituent of the MeOH extract and danshenol A (I) and (-)danshexinkun A(7) are the minor ones.
TL;DR: In this article, three phenolics including six new compounds were isolated from a commercial liquorice from North-eastern China, including tetrahydroxy-methoxychalcone, isolicopyranocoumarin, glycyrrhiza-flavonol A, A, B and C, respectively.
Abstract: Twenty-three phenolics including six new compounds were isolated from a commercial liquorice from North-eastern China. Structures 2-7 were assigned for the new compounds, designated as tetrahydroxy-methoxychalcone, isolicopyranocoumarin, glycyrrhiza-flavonol A, and glycyrrhiza-isoflavones A, B and C, respectively. Compound 2 showed the most potent scavenging effect on 1, 1-diphenyl-2-picrylhydrazyl radical among the tested polyphenols isolated from liquorice. Air-oxidation of 2 in alkaline dimethylsulfoxide solution gave strong ESR signals, indicating the stability of the radical species formed from 2.
TL;DR: Diesel exhaust particulates were extracted with benzene-ethanol and separated into five fractions by silica-gel column chromatography and direct-acting mutagenic activity was assayed by the Ames test, suggesting that the activities in the fractions were suppressed in the crude extract.
Abstract: Diesel exhaust particulates were extracted with benzene-ethanol (3 : 1, v/v) and separated into five fractions by silica-gel column chromatography. Direct-acting mutagenic activity was assayed by the Ames test using the Salmonella typhimurium YG1024 strain. The total activity of five fractions was about four times greater than that of the crude extract, suggesting that the activities in the fractions were suppressed in the crude extract. Strong activity was observed in fraction 4 which was eluted with dichloromethane (61.5% of the total activity) and fraction 5 which was eluted with ethanol (35.3%). Nitropolycyclic aromatic hydrocarbons (NPAHs) were determined by high-performance liquid chromatography with chemiluminescence detection. They were found mainly in fraction 4, although one NPAH was in fraction 3 which was eluted with n-hexane-dichloromethane (3 : 1, v/v). Based on these results, 53.1% of the activity in fraction 4 was attributed to NPAHs. The contribution of 1-nitropyrene and 1, 3-, 1, 6- and 1, 8-dinitropyrenes was great and that of the other NPAHs was small. The mutagenic compound in fraction 5 was not identified. Fractions 1 and 2, which were eluted with n-hexane, and fraction 3 suppressed the activity of fraction 4. Polycyclic aromatic hydrocarbons in fractions 2 and 3 were considered as possible suppressors of NPAHs.
TL;DR: The results suggest proper use of the CyD derivatives could be effective in designing rapid or long-acting insulin preparations, as well as the electrostatic interaction between the positive charges of insulin and the concentrated negative charges of the sulfate and sulfonate groups of the anionic beta-CyDs.
Abstract: Maltosyl-beta-cyclodextrin (G2-beta-CyD) suppressed the aggregation of insulin in neutral solution, while the sulfate of beta-CyD (S-beta-CyD) accelerated the aggregation. On the other hand, the sulfobutyl ether of beta-CyD (SBE-beta-CyD) showed varying effects on insulin aggregation, depending on the degree of substitution of the sulfobutyl group: i.e., the inhibition at relatively low substitution and acceleration at higher substitution. Differential scanning calorimetric studies indicate that the self-association of insulin stabilized the native conformation of the peptide, as indicated by an increase in the mean unfolding temperature (Tm). G2-beta-CyD and SBE-beta-CyD decreased the Tm value of insulin oligomers, while S-beta-CyD increased the Tm value. 1H-Nuclear magnetic resonance spectroscopic studies suggest that G2-beta-CyD includes accessible hydrophobic side chains of insulin within the CyD cavity, and hence perturbs the intermolecular hydrophobic contacts between aromatic side chains across the monomer-monomer interfaces. By contrast, the electrostatic interaction between the positive charges of insulin and the concentrated negative charges of the sulfate and sulfonate groups of the anionic beta-CyDs seems to be more of a factor than the inclusion effects. These results suggest proper use of the CyD derivatives could be effective in designing rapid or long-acting insulin preparations.
TL;DR: The first instance of the isolation of 6H-dibenzo[b, d]pyran-6-one derivatives from the lichen mycobiont was reported in this article.
Abstract: From the cultures of the spore-derived mycobionts of the lichen Graphis scripta var. pulverulenta, four phenolic compounds, graphislactones A-D, were isolated. Their structures were determined by spectroscopic methods. This is the first instance of the isolation of 6H-dibenzo[b, d]pyran-6-one derivatives from the lichen mycobiont.
TL;DR: The n-BuOH extract of Swertia japonica showed a significant hepatoprotective effect on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice, and led to the isolation of a new tetrahydroxanthone derivative, tetahydroswertianolin, as well as two known iridoids.
Abstract: The n-BuOH extract of Swertia japonica showed a significant hepatoprotective effect on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. The activity-guided fractionation led to the isolation of a new tetrahydroxanthone derivative, tetrahydroswertianolin (1), as well as two known iridoids, gentiopicroside (2) and sweroside (3). Their structures were elucidated by spectroscopic methods and chemical reactions. Of the three compounds, 2 and 3 possessed mild hepatoprotective activity at a dose range of 25-50 mg/kg, whereas, 1 exhibited potent activity in a dose-dependent manner. The hepatoprotective effect of tetrahydroswertianolin (1) was stronger than that of glycyrrhizin which was used as a positive control.
TL;DR: A xanthone derivative, subelliptenone F, and related compounds showed an intensive inhibitory effect against topoisomerases I and II in in vitro experiments as mentioned in this paper.
Abstract: A xanthone derivative, subelliptenone F, and the related compounds showed an intensive inhibitory effect against topoisomerases I and II in in vitro experiments. These xanthones are prospective lead compounds for anticancer drugs.
TL;DR: In this article, the 2-aroyl-1, 3-dimethylbenzimidazolium salt was shown to be an effective complex catalyst for aroylation.
Abstract: Refluxing of a mixture of benzaldehyde (1a), 1, 3-dimethylbenzimidazolium iodide (7), p-nitroaniline (9b) as an oxidizing agent, and 1, 8-diazabicyclo[5, 4, 0]-7-undecene (DBU) in MeOH afforded methyl benzoate (2a) in good yield. Other methyl arenecarboxylates 2 were similarly obtained from arenecarbaldehydes 1. We showed that this aroylation proceeds via the 2-aroyl-1, 3-dimethylbenzimidazolium salt (8). The 1, 2, 4-triazolium salt (18) and the naphtho[1, 2-d]imidazolium salt (19) were also effective catalysts for this oxidative aroylation. However, the aroylation did not proceed with the imidazolium salt (20). In the presence of flavins (25a-c), arenecarbaldehydes 1 reacted in MeOH under aerobic conditions catalyzed by the benzimidazolium salt 7 to give the corresponding methyl arenecarboxylates 2. 1-Methyl-3-[3-(10-phenylisoalloxazin-3-yl)propyl]benzimidazolium bromide (27) is an effective complex catalyst for this oxidative aroylation.
TL;DR: New dammarane-type triterpene oligoglycosides, juj Jubosides A1 and C and acetyljujuboside B1 were isolated from Zizyphi Spinosi Semen, the seeds of ZizYphus jujuba MILL.
Abstract: New dammarane-type triterpene oligoglycosides, jujubosides A1 and C and acetyljujuboside B, were isolated from Zizyphi Spinosi Semen, the seeds of Zizyphus jujuba MILL. var. spinosa HU, together with three known saponins. The structures of jujubosides A1 and C and acetyljujuboside B were determined on the basis of chemical and physicochemical evidence.Jujubosides A1 and C and acetyljujuboside B were found to inhibit the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.
TL;DR: All major chemical constituents from R. sacra inhibited the histamine release and, among them, lotaustralin and rhodiooctanoside were found to show potent inhibitory activity.
Abstract: The methanolic extract of the underground part of Rhodiola sacra (PRAIN ex HAMET) S. H. Fu was found to show inhibitory activity on the histamine release from rat peritoneal exudate cells induced by an antigen-antibody reaction. From the methanolic extract with the inhibitory activity on histamine release, a new cyanoglycoside called rhodiocyanoside D and two new monoterpene glycosides called sacranosides A and B were isolated, together with eight known compounds, rhodiocyanoside A, heterodendrin, lotaustralin, rhodioloside, 2-phenylethyl alpha-L-arabinopyranosyl(1-->6)-beta-D-glucopyranoside, 2-methyl-3-buten-2-yl beta-D-glucopyranoside, kenposide A, and rhodiooctanoside. The structures of new compounds were determined on the basis of chemical and physicochemical evidence, which included the synthesis of sacranoside A from (-)-myrtenol. All major chemical constituents from R. sacra inhibited the histamine release and, among them, lotaustralin and rhodiooctanoside were found to show potent inhibitory activity.
TL;DR: In this article, a depsidone named garcinisidone-A (1), six new xanthones named assiguxanthone-a (3), -B (9), -C (15), and -D (16), as well as some known xanthone, benzophenone, chromone, and biflavanone derivatives, and their structures were elucidated by spectroscopic methods.
Abstract: Constituents of three EtOH extracts of the stem bark of Garcinia assigu LANTB., Garcinia dulcis (ROXB.) KURZ., and Garcinia latissima MIQ., belonging to the Guttiferae, collected in Central Province of Papua New Guinea, were studied. A novel depsidone named garcinisidone-A (1), six new xanthones named assiguxanthone-A (3) and -B (9) and dulxanthone-A (4), -B (6), -C (7), and - D (11), and four new pyranoxanthones named latisxanthone-A (13), -B (14), -C (15), and -D (16) were isolated, as well as some known xanthone, benzophenone, chromone, and biflavanone derivatives, and their structures were elucidated by spectroscopic methods. Among these components, garcinisidone-A (1) is the first example of a depsidone derivative having a five-carbon unit (prenyl) as a substituent to be found in nature. Latisxanthone-B (14) was found to contain a hydroperoxy moiety in the molecule. This is the second example of a xanthone hydroperoxide to be found in nature.
TL;DR: In this paper, the effects of a solvent system on the pharmaceutical properties of carbamazepine (CBZ) granules containing a polymorphic form of bulk powder were investigated by X-ray diffraction analysis, thermal analysis, mercury porosimetry and Brunauer-Emmett-Teller (BET) surface area measurement.
Abstract: The effects of a solvent system on the pharmaceutical properties of carbamazepine (CBZ) granules containing a polymorphic form of bulk powder were investigated by X-ray diffraction analysis, thermal analysis, mercury porosimetry and Brunauer-Emmett-Teller (BET) surface area measurement. A powder mixture consisting of 20% CBZ form I, as a bulk powder, 56% crystalline α-lactose monohydrate and 24% corn starch was used as a pharmaceutical powder, with the three kinds of binder solutions (distilled water, 50% aqueous ethanol and ethanol) containing 5% hydroxypropylcellulose (HPC). After kneading with a binder solution, the granules were obtained using an extruding granulator. The X-ray diffraction and differential scanning calorimetry (DSC) results of the granules indicated that form I with 50% ethanol solution transformed into a dihydrate form during extruding granulation, but this did not occur with the distilled water or ethanol solutions. The order of hardness and specific surface area (Sw) of the granules was distilled water>50% ethanol>ethanol and 50% ethanol>ethanol>distilled water. The stress-thickness profiles of the tabletting compression processes of CBZ granules obtained using various binder solution systems were measured, and the initial compression process due to particle rearrangement was affected by the characteristics in the granules. The total pore volume of tablets obtained from 50% ethanol was the lowest, and their order was ethanol>distilled water>50% ethanol. Their order of tablet hardness reflected the total pore volume of the tablet, and was 50% ethanol>distilled water>ethanol. All pharmaceutical properties of the granules and/or tablets containing CBZ were affected by the characteristics of the solvent systems in binder solution.
TL;DR: In this paper, eight major pigments have been isolated from commercial Monascus pigments using NMR, MS, and semisyntheses and the structural data on the pigments were obtained using NMRI, MS and semi-synthesis.
Abstract: Eight major pigments have been isolated from commercial Monascus pigments. The structural data on the pigments were obtained using NMR, MS, and semisyntheses. The pigments were characterized as alanine or aspartate derivatives of the orange pigments of Monascus, monascorubrin (1) and rubropunctatin (2), which have an azaphilone structure. The semisyntheses revealed that the amino acid units of the isolated compounds were the D-forms as well as the L-forms.