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Showing papers in "Chemical & Pharmaceutical Bulletin in 2006"


Journal ArticleDOI
TL;DR: Among the isolates, alpha-mangostin (12), the major metabolite, exhibited the most potent effects against the BC-1 cells, an activity greater than that of the standard drug ellipticine (IC50 = 1.46 microg/ml), while gartanin (10) displayed the strongest activity against the NCI-H187 cells at the respective IC50 values.
Abstract: Three new prenylated xanthones, mangostenones C (1), D (2), and E (3), together with 16 known xanthones 4-19, were isolated from the young fruit (7-week maturity stage) of Garcinia mangostana. The structural elucidation of the new compounds was mainly established on the basis of 1D and 2D NMR and HR-MS spectroscopic analysis. Compound 1 showed cytotoxic properties against three human cancer cell lines, epidermoid carcinoma of the mouth (KB), breast cancer (BC-1), and small cell lung cancer (NCI-H187), with IC50 values of 2.8, 3.53, and 3.72 microg/ml, respectively. Among the isolates, alpha-mangostin (12), the major metabolite, exhibited the most potent effects against the BC-1 cells with an IC50 value of 0.92 microg/ml, an activity greater than that of the standard drug ellipticine (IC50 = 1.46 microg/ml). Compound 12 also showed the highest activity against KB cells, while gartanin (10) displayed the strongest activity against the NCI-H187 cells at the respective IC50 values of 2.08 microg/ml and 1.08 microg/ml.

210 citations


Journal ArticleDOI
TL;DR: This finding is the first demonstration that major pure cucurbutanoid compounds of M. charantia have in vivo hypoglycaemic effects.
Abstract: Bioguided fractionation of the methanol extract of Momordica charantia dried gourds led to the isolation of three new cucurbitane triterpenoids (1—3), together with eight known compounds (4—11). The aglycone of momordicoside I was isolated from the ether soluble fraction in a high amount. The structures of the metabolites were established on the basis of one and two dimensional NMR spectroscopic evidence, X-ray analysis, and comparison with the reported data in the literature. A number of phytochemicals have been isolated from Momordica charantia but the constituents responsible for the hypoglycaemic/antihyperglycaemic activities have not been determined. Therefore, in order to evaluate the contribution of the cucurbitane triterpenoids of the ether fraction of M. charantia methanol extract to in vivo anti-diabetic effects, the major compounds, 5β,19-epoxy-3β,25-dihydroxycucurbita-6,23(E)-diene (4), and 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al (5) have been tested and have shown blood hypoglycaemic effects in the diabetes-induced male ddY mice strain at 400 mg/kg. The two aglycones of charantin did not show any hypoglycaemic effects. Our finding is the first demonstration that major pure cucurbutanoid compounds of M. charantia have in vivo hypoglycaemic effects.

204 citations


Journal ArticleDOI
TL;DR: Assessment of the suitability of spray dried excipient base in the formulation of ODTs of Valdecoxib and Metoclopramide shows the superiority of the spray driedexcipient base technique over direct compression technique.
Abstract: Orally disintegrating tablets (ODT) are gaining popularity over conventional tablets due to their convenience in administration and suitability for patients having dysphagia. Moreover no water is required for swallowing the tablets and hence suitable for geriatric, pediatric and traveling patients. The purpose of this study is to assess the suitability of spray dried excipient base in the formulation of ODTs of Valdecoxib (low aqueous solubility) and Metoclopramide (high aqueous solubility). Spray dried excipient base was prepared using Scientech spray drier. Super disintegrants (such as Ac-Di-Sol, Kollidon CL, sodium starch glycolate), diluent (mannitol) alongwith sweetening agent (aspartame) were used in the formulation of tablets. The tablets were evaluated for hardness, friability, water absorption ratio, disintegration time (DT) and in vitro drug release. Using the same excipients, the tablets were prepared by direct compression and were evaluated in the similar way. Maximum drug release and minimum DT were observed with Kollidon CL excipient base as compared to tablets prepared by direct compression, showing the superiority of the spray dried excipient base technique over direct compression technique.

100 citations


Journal ArticleDOI
TL;DR: A series of potential biologically active 2-(4-hydroxy- 1,1-dioxido-2H-1,2-benzothiazin-3-yl)quinazolin-4(3H)-ones was synthesized in a straight forward manner and subjected to preliminary evaluation for their biological activity against Gram positive and Gram negative bacteria.
Abstract: A series of potential biologically active 2-(4-hydroxy-1,1-dioxido-2H-1,2-benzothiazin-3-yl)quinazolin-4(3H)-ones was synthesized in a straight forward manner by condensation of respective 4-hydroxy-1,2-benzothiazine-1,1-dioxides with anthranilamide followed by simple and high throughput cyclization of N-[2-(aminocarbonyl)phenyl]-4-hydroxy-1,2-benzothiazine-3-carboxamide-1,1-dioxides. All the synthesized compounds were subjected to preliminary evaluation for their biological activity against Gram positive and Gram negative bacteria. Some of the assayed compounds showed marked activity against Bacillus subtilis.

100 citations


Journal ArticleDOI
TL;DR: One new and eight known ceanothane- and lupane-type triterpenes were isolated from the root bark of Ziziphus cambodiana PIERRE (Rhamnaceae) and the structure of the new compound was elucidated as 3-O-(4-hydroxy-3-methoxybenzoyl)ceanothic acid (3-O-vanillylceanothi acid) (1).
Abstract: One new and eight known ceanothane- and lupane-type triterpenes were isolated from the root bark of Ziziphus cambodiana PIERRE (Rhamnaceae). Based on spectral analyses, the structure of the new compound was elucidated as 3-O-(4-hydroxy-3-methoxybenzoyl)ceanothic acid (3-O-vanillylceanothic acid) (1), while the known compounds were identified as lupeol (2), betulinaldehyde (3), betulinic acid (4), 2-O-E-p-coumaroyl alphitolic acid (5), alphitolic acid (6), zizyberanalic acid (7), zizyberenalic acid (8) and ceanothic acid (9). Compounds 1, 5 and 8 exhibited significant in vitro antiplasmodial activity against the parasite Plasmodium falciparum, with inhibitory concentration (IC50) values of 3.7, 0.9 and 3.0 μg/ml, respectively. Compounds 1 and 3—8 showed antimycobacterial activity against Mycobacterium tuberculosis with respective MIC values of 25, 25, 25, 12.5, 50, 50 and 100 μg/ml.

93 citations


Journal ArticleDOI
TL;DR: An efficient synthesis of the antiviral and antioxidative chromene (1) was achieved and a small amount of chromene 1 could be derived from plastoquinones 2 and 3, the major constituents of the brown alga, Sargassum micracanthum.
Abstract: An efficient synthesis of the antiviral and antioxidative chromene (1) was achieved. A small amount of chromene 1 could be derived from plastoquinones 2 and 3, the major constituents of the brown alga, Sargassum micracanthum. By the following synthetic scheme involving its application, many kinds of analogs can be synthesized for evaluation of their biological activity and mechanistic study. The total synthesis of 1, started from geranyl acetate and protected 2-bromo-6-methylhydroquinone, was executed with Sharpless asymmetric dihydroxylation for introduction of the terminal diol system and base-catalyzed sigmatropic rearrangement for construction of the chromene skeleton as the crucial steps. The stereochemistry at C-11′ was reconfirmed by this synthesis.

87 citations


Journal ArticleDOI
TL;DR: The two fold broth dilution and agar dilution method were used to study essential oil of two Houttuynia THUNB.
Abstract: Houttuynia THUNB. (Saururaceae) has been used for dozens of years in China for the treatment of cough, leucorrhea and ureteritis. The essential oils from the two species: Houttuynia emeiensis and Houttuynia cordata sold in China under one trade name ‘Yuxingcao’, obtained by hydrodistillation, were analyzed by GC-MS. The results show that fifty-five components were identified and methyl nonyl ketone (2.10—40.36%), bornyl acetate (0.4—8.61%) and β-myrcene (2.58—18.47%) were the most abundant components in oil, but the percentage of most of compounds in different species and parts varied greatly. The two fold broth dilution and agar dilution method were used to study essential oil of two Houttuynia THUNB. species for their antibacterial properties against microorganisms, Staphylococcus aureus and Sarcina ureae. The two fold dilution method was allowed to determine the minimum inhibitory concentration (MIC) of essential oil from different parts and species. Results showed that all essential oils possessed antibacterial effect, with MIC values in the range of 0.0625×10−3 to 4.0×10−3 ml/ml. However, essential oil from different parts and species differed clearly in their antibacterial activities. The essential oil from the aboveground part of the cultivated Houttuynia emeiensis exhibited higher activity than both parts of the wild and cultivated Houttuynia cordata when used on Staphylococcus aureus (MIC=0.25×10−3 ml/ml) and Sarcina ureae (MIC=0.0625×10−3 ml/ml), and had the same activity as the positive control ampicillin sodium.

82 citations


Journal ArticleDOI
TL;DR: Three new cucurbitane-type triterpene called karavilagenins A, B, and C and five new cucurbane- type triterPene glycosides called kARavilosides I, II, III, IV, and V were isolated from the dried fruit of Sri Lanka.
Abstract: Three new cucurbitane-type triterpene called karavilagenins A, B, and C and five new cucurbitane-type triterpene glycosides called karavilosides I, II, III, IV, and V were isolated from the dried fruit of Sri Lanka Momordica charantia L. (Cucurbitaceae) together with two known cucurbitane-type triterpenes, 19(R)-methoxy-5beta,19-epoxycucurbita-6,23-dien-3beta,25-diol and 5,19-epoxycucurbita-6,23-diene-3,25-diol, and nine known cucurbitane-type triterpene glycosides, goyaglycosides-b, -c, and -d, and momordicosides F1, F2, G, I, K, and L. The structures of karavilagenins and karavilosides were elucidated on the basis of chemical and physicochemical evidence.

82 citations


Journal ArticleDOI
TL;DR: An efficient one-pot synthesis of polyhydroquinolines by four-component coupling reactions of aldehydes, ethyl acetoacetate, dimedone and ammonium acetate in the presence of HY-zeolite at ambient temperature has been achieved.
Abstract: An efficient one-pot synthesis of polyhydroquinolines by four-component coupling reactions of aldehydes, ethyl acetoacetate, dimedone and ammonium acetate in the presence of HY-zeolite at ambient temperature has been achieved. The conversions took shorter times to form the products in excellent yields. HY-zeolite can be recovered and reused.

78 citations


Journal ArticleDOI
TL;DR: Sixteen compounds were isolated from the fresh roots of Piper sarmentosum and Sarmentamide A, B, and C are new natural products, which were tested for antiplasmodial, antimycobacterial and antifungal activities.
Abstract: Sixteen compounds were isolated from the fresh roots of Piper sarmentosum. Seven of these have been previously isolated from the fruits and leaves of this plant: the aromatic alkene (1), 1-allyl-2-methoxy-4,5-methylenedioxybenzene (4), beta-sitosterol, pyrrole amide (6), sarmentine (10), sarmentosine (13) and pellitorine (14). (+)-Sesamin (2), horsfieldin (3), two pyrrolidine amides 11 and 12, guineensine (15) and brachystamide B (16) are new for P. sarmentosum. Sarmentamide A, B, and C (7-9) are new natural products. Compounds 1--4 and 6--16 were tested for antiplasmodial, antimycobacterial and antifungal activities.

76 citations


Journal ArticleDOI
TL;DR: A new prenylated xanthone, 5-O-methylcelebixanthone (1), together with six known compounds, were isolated from roots of Cratoxylum cochinchinense by spectroscopic methods and showed cytotoxic activity against the human lung cancer cell line and antimalarial activity against Plasmodium falciparum.
Abstract: A new prenylated xanthone, 5-O-methylcelebixanthone (1), together with six known compounds; celebixanthone (2), 1,3,7-trihydroxy-2,4-di(3-methylbut-2-enyl)xanthone (3), cochinchinone A (4), alpha-mangostin (5), beta-mangostin (6) and cochinchinone C (7) were isolated from roots of Cratoxylum cochinchinense. Their structures were elucidated by spectroscopic methods. Compounds 2 and 4-7 showed cytotoxic activity against the human lung cancer cell line (NCI-H187) with IC(50) values ranging from 0.65 to 5.2 microg/ml. Compounds 1, 2, 6 and 7 also showed antimalarial activity against Plasmodium falciparum with IC(50) values of 3.2, 4.9, 7.2 and 2.6 microg/ml, respectively.

Journal ArticleDOI
TL;DR: The methanol extract and pure compounds were tested on two strains of Plasmodium falciparum, F32 ( chloroquine sensitive) and FcM29 (chloroquine resistant) and the IC50 values obtained ranged from 0.6 to 8.9 microg/ml.
Abstract: Further study of the methanol extract of the stem bark of Allanblackia monticola STANER L.C. resulted in the isolation of a new prenylated xanthenedione, designated allanxanthone C, together with the five known xanthones, garciniafuran, tovophyllin A, rubraxanthone, norcowanin and mangostin and one saponin, stigmasterol-3-O-beta-D-glucopyranoside. The structure of the new compound was established by detailed spectroscopic analysis to be 1,2-dihydro-3,6,8-trihydroxy-1,1,7-tri(3-methylbut-2-enyl)xanthen-2,9-dione (3-hydroxyapetalinone C). The methanol extract and pure compounds were tested on two strains of Plasmodium falciparum, F32 (chloroquine sensitive) and FcM29 (chloroquine resistant). The IC50 values obtained ranged from 0.6 to 8.9 microg/ml. Their cytotoxicity was estimated on human melanoma cells (A375) and the cytotoxicity/antiplasmodial ratio was found to be between 15.45 and 30.46. The antimicrobial activities against a range of microorganisms of the crude extract and some of these compounds are also reported.

Journal ArticleDOI
TL;DR: Nineteen biscoumarins bearing free and modified hydroxyl substituents at benzoyloxyphenyl linker have been synthesized by multiple step synthesis and thirteen were found to be active molecules against HIV-1 integrase (HIV-1 IN).
Abstract: Nineteen biscoumarins bearing free and modified hydroxyl substituents at benzoyloxyphenyl linker have been synthesized by multiple step synthesis. Among these biscoumarins, thirteen were found to be active molecules against HIV-1 integrase (HIV-1 IN). The structure-activity relationship of the nineteen compounds on HIV IN may be useful for the design of potent therapeutic agents.

Journal ArticleDOI
TL;DR: The results of ANOVA revealed that there are no significant differences between the accuracy of the predicted solubilities employing various log P values and the applicability of the proposed method could be extended for predicting the solubility of drugs in water-PEG 400 mixtures at various temperatures.
Abstract: A numerical method is proposed for predicting solubility of drugs in water–PEG 400 mixtures based on the Jouyban–Acree cosolvency model. The accuracy of the proposed method is evaluated by computing mean percentage deviation (MPD) and compared with that of log-linear model of Yalkowsky. The overall MPDs of the Jouyban–Acree model and the most accurate version of Yalkowsky's model are 39.8 (±46.7) % and 175.8 (±266.4) %, respectively, and the mean difference is statistically significant (p<0.0005). The proposed method produces acceptable residual distribution and the probability of solubility prediction with residual log of solubility <0.5 unit is 0.86. The applicability of the proposed method could be extended for predicting the solubility of drugs in water–PEG 400 mixtures at various temperatures. The impact of various log P values computed using different software is also studied and the results of ANOVA revealed that there are no significant differences between the accuracy of the predicted solubilities employing various log P values.

Journal ArticleDOI
TL;DR: The Jouyban-Acree model has been used to predict thesolubility of paracetamol in water-ethanol-propylene glycol binary and ternary mixtures based on model constants computed using a minimum number of solubility data of the solute in water/ethanol/propylene/ethylene binary mixtures.
Abstract: The Jouyban-Acree model has been used to predict the solubility of paracetamol in water-ethanol-propylene glycol binary and ternary mixtures based on model constants computed using a minimum number of solubility data of the solute in water-ethanol, water-propylene glycol and ethanol-propylene glycol binary mixtures. Three data points from each binary solvent system and solubilities in neat solvents were used to calculate the binary interaction parameters of the model. Then the solubility at other binary solvent compositions as well as in a number of ternary solvents were predicted, and the mean percentage deviation (+/-S.D.) of predicted values from experimental solubilities was 7.4(+/-6.1)%.

Journal ArticleDOI
TL;DR: In this paper, 13 xanthones (1-13) were isolated from the resin of Garcinia hanburyi and two new compounds (namely gaudichaudic acid, and isogambogenic acid, 1, 2) were identified on the basis of extensive spectral evidence including detailed 2D NMR data.
Abstract: Thirteen xanthones (1-13) were isolated from the resin of Garcinia hanburyi. Among them, two new compounds (namely gaudichaudic acid, and isogambogenic acid, 1, 2), and one new natural product (deoxygaudichaudione A, 3) were identified on the basis of extensive spectral evidence including detailed 2D NMR data. Ten of these xanthones were tested for their cytotoxicities against human leukemia K562 (K562/S) and doxorubicin-resistant K562 (K562/R) cell lines, and showed similar inhibitory effects on both cell lines, suggesting that this group of polyprenylated xanthones might not be multidrug resistance (MDR) substrates.

Journal ArticleDOI
TL;DR: Two new acetylenic glucosides, 4',6'-acetonide-8Z-decaene-4,6-diyne-1-O-beta-D-glucopyranoside named carthamoside A and 4, 6-decadiyne
Abstract: Two new acetylenic glucosides, 4′,6′-acetonide-8Z-decaene-4,6-diyne-1-O-β-D-glucopyranoside named carthamoside A1 (1) and 4,6-decadiyne-1-O-β-D-glucopyranoside named carthamoside A2 (2), along with one known acetylenic glucoside, 8Z-decaene-4,6-diyne-1-O-β-D-glucopyranoside (3), have been isolated from the air-dried flower of Carthamus tinctorius, these structures have been identified on the basis of spectroscopic methods.

Journal ArticleDOI
TL;DR: A simple and sensitive reversed phase high performance liquid chromatographic (HPLC) method has been developed for the simultaneous determination of twelve bacopa saponins present in the extracts of the Indian Medicinal Plant, Bacopa monnieri.
Abstract: A simple and sensitive reversed phase high performance liquid chromatographic (HPLC) method has been developed for the simultaneous determination of twelve bacopa saponins present in the extracts of the Indian Medicinal Plant, Bacopa monnieri. The separation was achieved on a reversed phase C(18) column (Luna C(18)), 5 microm by isocratic elution with 0.05 M sodium sulphate buffer (pH 2.3) and acetonitrile (68.5 : 31.5, v/v) as the mobile phase at a flow rate of 1.0 ml/min with an operating temperature of 30 degrees C. The method was validated for linearity, precision, intra- and inter-day precision and accuracy. Several Bacopa samples (plant materials, extracts and commercial formulations) were successfully analyzed. Major bacopasaponins were bacosides A(3) (3), bacopaside II (4), bacopaside I (5), bacopaside X (6), bacopasaponin C (7), bacopaside N2 (9) and the minor components were bacopasaponin F (1), bacopasaponin E (2), bacopaside N1 (8) bacopaside III (10), bacopaside IV (11) and bacopaside V (12). The total saponin content in the samples, plant materials and extracts varied from 5.1 to 22.17% and 1.47 to 66.03 mg/capsule or tablet in the commercial formulations.

Journal ArticleDOI
TL;DR: The results suggest the potential of the use of the cationic liposomes for the intradermal delivery of lipophilic drugs like retinoic acid in excised guinea pig dorsal skin.
Abstract: We studied the delivery of retinoic acid to skin by using cationic liposomes consisting of double-chained cationic surfactant, phosphatidylcholine (PC) and retinoic acid in excised guinea pig dorsal skin. Egg yolk PC liposomes contaning retinoic acid at a molar ratio of 4 : 1 increased the delivery of retinoic acid about two-fold, compared with its addition as an isopropyl myristate solution. Cationic liposomes containing 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) further enhanced the incorporation dependent on the DOTAP content. Liposomes consisting of DOTAP, egg yolk PC, and retinoic acid at a molar ratio of 2 : 2 : 1 induced a 3.7-fold increase in the skin incorporation compared with the egg yolk PC liposomes without DOTAP. Significant difference was not observed when either dimyristoylphosphatidylcholine (DMPC) or dipalmitoylphosphatidylcholine (DPPC) was used instead of egg yolk PC as well as when dimethyldipalmitylammonium was used instead of DOTAP. These results suggest the potential of the use of the cationic liposomes for the intradermal delivery of lipophilic drugs like retinoic acid.

Journal ArticleDOI
TL;DR: Mechanofusion with Mg-St or sucrose stearate could be an effective method to improve FPF of a DPI drug formulation and IGC would be a valuable method to investigate the interaction between a drug and the DPI carrier.
Abstract: The effect of lactose carrier surface property on the inhalation profile of dry powder inhaler (DPI) was evaluated using a micronized drug (Compound A) by inverse gas chromatography (IGC). Mechanofusion with magnesium stearate (Mg-St) or sucrose stearate increased the fine particle fraction (FPF), considered to be due to decrease in the interaction between Compound A and the lactose carrier. The effect of Compound A concentration on FPF was smaller in mechanofusion-processed lactose compared to intact lactose, especially when processed with Mg-St. The relationship between the IGC parameters of the lactose and FPF was also investigated. FPF increased as both the dispersive component of the surface energy and acidity similarity between the lactose carriers and Compound A increased. Although further investigation is necessary, it could be suggested that acidity similarity decreases the interaction between Compound A and lactose, thus contributing to the increase in the FPF. In conclusion, (1) mechanofusion with Mg-St or sucrose stearate could be an effective method to improve FPF of a DPI drug formulation; (2) IGC would be a valuable method to investigate the interaction between a drug and the DPI carrier; and (3) a relationship between surface acidity and inhalation profile was suggested.

Journal ArticleDOI
TL;DR: Euphoheliosnoid D (1), a new jatrophone-type diterpenoid, was isolated together with 22 known metabolites from the Chinese medicinal herb Euphorbia helioscopia L and the structure and relative stereochemistry of 1 was elucidated on the basis of spectroscopic methods.
Abstract: Euphoheliosnoid D (1), a new jatrophone-type diterpenoid, was isolated together with 22 known metabolites from the Chinese medicinal herb Euphorbia helioscopia L. The structure and relative stereochemistry of 1 was elucidated on the basis of spectroscopic methods. Compounds 14—23 were obtained from the species for the first time while compound 14, 2α-hydroxy helioscopinolide B, was isolated as a new natural product.

Journal ArticleDOI
TL;DR: A new anthracene glycoside, asperflavin ribofuranoside, and the previously described polyketides, flavoglaucin, isodihydroauroglauc in, and citrinin have been isolated from the marine-derived fungus Microsporum sp.
Abstract: A new anthracene glycoside, asperflavin ribofuranoside (1), and the previously described polyketides, flavoglaucin (2), isodihydroauroglaucin (3), and citrinin (4) have been isolated from the marine-derived fungus Microsporum sp. The structure and absolute stereochemistry of a new compound (1) was assigned on the basis of physicochemical data. Compounds 1—3 exhibited a significant radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC50 values of 14.2, 11.3, and 11.5 μM, respectively, which are more potent than the positive control, ascorbic acid (IC50, 20 μM). Compound 1 also showed a moderate antibacterial activity against the methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA) with MIC value of 50 μg/ml.

Journal ArticleDOI
TL;DR: The results show the usefulness of laccase for the synthesis of potential new antibiotics and protected mice against an infection with Staphylococcus aureus lethal to the untreated animals.
Abstract: Eight novel penicillins were synthesized by heteromolecular reaction of ampicillin or amoxicillin with 2,5-dihydroxybenzoic acid derivatives using a laccase from Trametes spec. All products inhibited the growth of several gram positive bacterial strains in the agar diffusion assay, among them methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci. The products protected mice against an infection with Staphylococcus aureus lethal to the untreated animals. Cytotoxicity and acute toxicity of the new compounds were neglectable. The results show the usefulness of laccase for the synthesis of potential new antibiotics. The biological activity of the new compounds stimulates intensified pharmacological tests.

Journal ArticleDOI
TL;DR: In this paper, the physicochemical properties and drug release profiles of hydrogels composed of silk protein (SP) polymers were evaluated for buprenorphine delivery in vitro.
Abstract: The objective of this study was to characterize and evaluate the physicochemical properties and drug release profiles of hydrogels composed of silk protein (SP) polymers. SPs with a low MW (SPL, ca. 18 kDa) and a high MW (SPH, ca. 76 kDa) were used for preparing hydrogels. Both the random coil form and β-sheet conformation simultaneously existed in the hydrogels according to Fourier-transformed IR determination. Morphologically, the hydrogels showed a sponge-like cross-linked structure produced by physical entanglement as well as chemical hydrogen and covalent bindings. The in vitro buprenorphine delivery from SPH hydrogels showed a slow-release effect, and a zero-order rate was obtained for all preparations. Drug release could be controlled by varying the SPH concentrations or incorporation of SPL into the systems. SP hydrogels showed a stronger barrier property for hydrophilic solutes than for hydrophobic solutes. The incorporation of SPH into Pluronic F-127 (PF-127) hydrogels changed the gel structure from amorphous micelles to a regularly interconnected texture with pores. Furthermore, SPH as an adjuvant polymer in PF-127 and chitosan hydrogels lowered and controlled the amount of drug released from those systems.

Journal ArticleDOI
Sheng-Jun Dai1, Meng Chen1, Ke Liu1, Yongtao Jiang1, Li Shen1 
TL;DR: Four new neo-clerodane diterpenoid alkaloids, named scutebarbatines C-F (1-4), were isolated from the whole plants of Scutellaria barbata D. DON and in vitro, compounds 1-4 showed significant cytotoxic activities against three human cancer cell lines.
Abstract: Four new neo-clerodane diterpenoid alkaloids, named scutebarbatines C-F (1-4), were isolated from the whole plants of Scutellaria barbata D. DON. Their structures were elucidated by spectral analyses (UV, IR, FAB-MS, 1D-NMR and 2D-NMR). In vitro, compounds 1-4 showed significant cytotoxic activities against three human cancer cell lines, namely, HONE-1 nasopharyngeal, KB oral epidermoid carcinoma, and HT29 colorectal carcinoma cells, and gave IC(50) values in the range 3.9-7.8 muM.

Journal ArticleDOI
TL;DR: Two bisanthraquinones named (+)-epicytoskyrin and (+)-1,1'-bislunatin were produced by the endophytic fungus from a tea plant, which is a species closely related to Diaporthe phaseolorum strain sw-93-13.
Abstract: Two bisanthraquinones named (+)-epicytoskyrin (1) and (+)-1,1'-bislunatin (2) were produced by the endophytic fungus from a tea plant, which is a species closely related to Diaporthe phaseolorum strain sw-93-13. The chemical structures of the metabolites were elucidated on the basis of the physicochemical properties including the circular dichroism (CD) spectrum.

Journal ArticleDOI
TL;DR: The rapid dissolution rate from the SDs was attributed to the amorphization of drug, improved specific surface area and wettability than the original drug crystals, and the specificsurface area and the adsorbed water amount of theSDs were significantly improved.
Abstract: Solid dispersions (SD) of nitrendipine (NTD), a poorly water-soluble drug, were prepared using the melt-mixing method with hydrophilic silica particles (Aerosil and Sylysia) with different particle size and specific surface areas as carriers. Powder X-ray diffraction and differential scanning calorimetry evaluation showed that NTD in the SDs treated with the melt-mixing method was dispersed in the amorphous state. FT-IR spectroscopy obtained with the SDs indicated the presence of hydrogen bonding between the secondary amine groups of NTD and silanol groups of silica particles. The dissolution property of NTD in the SDs was remarkably improved regardless of the grade of silica. At the end of the dissolution test (60 min) the concentrations of NTD for the SDs with Aerosil 200 and Sylysia 350 were 8.88 and 10.09 μg/ml, corresponding to 28 and 31 times that of the original NTD crystals, respectively. The specific surface area and the adsorbed water amount of the SDs were also significantly improved. The rapid dissolution rate from the SDs was attributed to the amorphization of drug, improved specific surface area and wettability than the original drug crystals. In the stability test, powder X-ray diffraction pattern indicated that amorphous NTD in the SD with Aerosil 200 was stable for at least 1 month under the humid conditions (40 °C/75% RH).

Journal ArticleDOI
TL;DR: The biological activity of the essential oils was evaluated in various human pathogenic microorganisms using the broth microdilution method and an unknown component isolated from the essential oil was characterized by means of MS, HR-MS, FT-IR, 1D- and 2D-NMR techniques as isofaurinone.
Abstract: The essential oil of aerial parts, leaves and flowers of the endemic Anthemis aciphylla BOISS. var. discoidea BOISS. (Asteraceae) were obtained by hydrodistillation. The oils were analyzed both by GC and GC-MS on a polar column. The monoterpenes α-pinene (9—49%) and terpinen-4-ol (22—32%) were characterized as the main constituents. An unknown component isolated from the essential oil was characterized by means of MS, HR-MS, FT-IR, 1D- and 2D-NMR techniques as isofaurinone (1). Furthermore, the biological activity of the essential oils was evaluated in various human pathogenic microorganisms using the broth microdilution method. Weak to moderate inhibitions (0.06—1.0 mg/ml) was observed.

Journal ArticleDOI
TL;DR: Two selenoglycosiede, SG-3 and SG-8, among eleven selenium-containing compounds examined, were discovered to be effective depigmenting compounds on a mushroom tyrosinase inhibitory assay and showed dose-dependently cytotoxicity in a study of inhibition melanin synthesis by melan-a cells.
Abstract: This study reports depigmenting potency of selenium-containing carbohydrates, which would be based upon the finding of direct inhibition to mushroom tyrosinase. Two selenoglycosiede, SG-3 (bis(2,3,4-tri-O-acetyl-β-D-arabinopyranosyl) selenide) and SG-8 (4′-methylbenzoyl 2,3,4,6-tetra-O-acetyl-D-selenomanopyranoside) among eleven selenium-containing compounds examined, were discovered to be effective depigmenting compounds on a mushroom tyrosinase inhibitory assay. SG-3 exhibited a competitive inhibition effect that was similar to kojic acid, well-known tyrosinase inhibitor. At 100 μM and 150 μM, SG-8 had an uncompetitive inhibitory effect that was higher than kojic acid. A study of a melan-a cell originated-tyrosinase inhibition assay showed that SG-8 had a lower inhibitory effect than kojic acid. SG-3 showed a similar inhibition effect to kojic acid on the melan-a cell-originated tyrosinase inhibitory assay. SG-8 showed dose-dependently cytotoxicity in a study of inhibition melanin synthesis by melan-a cells. Most melan-a cells did not survive after being treated with 20 μM of SG-8. At 10 μM, SG-3 inhibited melanin synthesis in the melan-a cells, and the effect was similar to phenylthiourea, which is a well-known inhibitor of melanin synthesis. Therefore, SG-3 is a new candidate for depigmenting reagents.

Journal ArticleDOI
TL;DR: Four new iridoid glycosides, kankanosides A, B, C, and D, and an acyclic monoterpene glycoside, kanksanoside E, were isolated from the methanolic extract of dried stems of Cistanche tubulosa by R. WIGHT (Orobanchaceae) together with 16 known compounds.
Abstract: Four new iridoid glycosides, kankanosides A (1), B (2), C (3), and D (4), a chlorinated iridoid, kankanol (5), and an acyclic monoterpene glycoside, kankanoside E (6), were isolated from the methanolic extract of dried stems of Cistanche tubulosa (SCHRENK) R. WIGHT (Orobanchaceae) together with 16 known compounds. The structures of these new compounds (1-6) were determined on the basis of the chemical and physicochemical evidence.