Showing papers in "Chemical & Pharmaceutical Bulletin in 2011"
TL;DR: A compilation of new naturally occurring iridoids and secoiridoids including their glycosides, esters, aglycones, derivatives and dimers reported during mid 2008-2010 is provided with available physical and spectral data.
Abstract: A compilation of new naturally occurring iridoids and secoiridoids including their glycosides, esters, aglycones, derivatives and dimers reported during mid 2008—2010 is provided with available physical and spectral data: mp, [a]D, UV, IR, circular dichroism (CD), 1 H- and 13 C-NMR as well as natural source with family and references. The important bioactivity of new and known iridoids and secoiridoids reported during this period is also highlighted.
125 citations
TL;DR: No interaction was observed in between drug and polymer and crystallinity of drug was not changed in drug loaded nanoparticles, and tested formulation was non-irritant with no sign of inflammation.
Abstract: The aim of this investigation was to develop 5-fluorouracil (5-FU) loaded chitosan nanoparticles (CH-DNPs) for ophthalmic delivery. CH-DNPs were fabricated by ionotropic gelation mechanism using chitosan (CH) and a polyanion (TPP). The nanoparticles were smooth and spherical, confirmed by scanning electron microscopy (SEM) and atomic force microscope (AFM). CH/TPP mass ratio and TPP significantly changed the particles size morphology and encapsulation efficiency. The nanoparticles size ranged from approximately 114 to 192 nm and had a positive zeta potential (30±4 mV). The encapsulation efficiency, loading capacity and recovery of DNPs were 8.12-34.32%, 3.14-15.24% and 24.22 to 67% respectively. Physical characterization was done by Fourier transform infrared (FT-IR) and X-ray diffraction (XRD). No interaction was observed in between drug and polymer and crystallinity of drug was not changed in drug loaded nanoparticles. In-vitro release study of DNPs showed diffusion controlled release. Bioavailability study of batch CS9 was studied in rabbit eye and compare to 5-FU solution. 5-FU level was significantly higher in aqueous humor of rabbit eye. Ocular tolerance was studied in the eye of New Zealand rabbits and tested formulation was non-irritant with no sign of inflammation.
95 citations
TL;DR: Results indicate that an eucalyptol microemulsion system is a promising tool for the percutaneous delivery of curcumin in transdermal delivery vehicle.
Abstract: Microemulsions have received great attention for applications in transdermal drug delivery. The use of curcumin for treating various skin diseases like scleroderma, psoriasis, and skin cancer was extensively reported. The solubility of curcumin in various oils, surfactants, and cosurfactants was studied herein in order to find the optimal components for a transdermal delivery vehicle. Microemulsion systems composed of eucalyptol, polysorbate 80, ethanol, and water were developed as transdermal delivery vehicles for curcumin. Effects of the microemulsion composition on transdermal curcumin delivery were studied using Franz diffusion cells. The transdermal curcumin flux, permeability coefficient, and enhancement ratio were analyzed to evaluate the effects of eucalyptol/water ratios in the microemulsions. Pseudo-ternary phase diagrams of the eucalyptol microemulsions with various surfactant/cosurfactant ratios (1 : 1—1 : 3) were constructed to investigate their phase behaviors. Conductivity, interfacial tension, size, and viscosity data of the microemulsions were used to characterize the physicochemical properties of transdermal vehicles. The influence of the microemulsions on skin histology and on the delivery route was analyzed using hematoxylin/eosin staining and confocal laser scanning microscopy. In conclusion, microemulsions were successfully developed for transdermal curcumin delivery after screening various components and adjusting the oil/water ratios. The curcumin permeation rate of the microemulsion developed was 15.7-fold higher than that of the control (eucalyptol only). These results indicate that an eucalyptol microemulsion system is a promising tool for the percutaneous delivery of curcumin.
83 citations
TL;DR: 3,4,5-tri-O-caffeoylquinic acid showed the highest accelerating activity on ATP production among tested compounds after it was suggested that caffeoyl groups bound to quinic acid are important for activity and the more caffeoyL groups are bound toQuinic acid, the higher accelerating activityon ATP production exhibits.
Abstract: Caffeoylquinic acid (CQA) is one of the phenylpropanoids which have various bioactivities such as antioxidant, antibacterial, anticancer, antihistamic, and other biological effects. We previously reported that 3,5-di-O-caffeoylquinic acid inhibited amyloid β1—42-induced cellular toxicity on human neuroblastoma SH-SY5Y cells and increased the mRNA expression level of glycolytic enzymes and the intracellular ATP level. To investigate structure–activity relationship on the accelerating activity on ATP production, we synthesized 1,4,5-tri-O-caffeoylquinic acid, 4,5-di-O-caffeoylquinic acid, 3,4,5-tri-O-caffeoylquinic acid, and other derivatives. Additionally, we evaluated intracellular ATP level in SH-SY5Y treated with each CQA derivative. As a result, 3,4,5-tri-O-caffeoylquinic acid showed the highest accelerating activity on ATP production among tested compounds. It was suggested that caffeoyl groups bound to quinic acid are important for activity and the more caffeoyl groups are bound to quinic acid, the higher accelerating activity on ATP production exhibits.
64 citations
TL;DR: 9-Azanoradamantane N-oxyl (Nor-AZADO 4), constituting an unhindered, stable nitroxyl radical, exhibits superior catalytic activity to 2,2,6,6-tetramethylpiperidine-1-oxol (TEMPO) and AZADOs in the oxidation of alcohols to their corresponding carbonyl compounds.
Abstract: A highly active organocatalyst for alcohol oxidation has been developed. 9-Azanoradamantane N-oxyl (Nor-AZADO 4), constituting an unhindered, stable nitroxyl radical, exhibits superior catalytic activity to 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and AZADOs in the oxidation of alcohols to their corresponding carbonyl compounds.
62 citations
TL;DR: This is the first report to identify cannabimimetic compound (1) as a designer drug and to show its binding affinity to cannabinoid receptors.
Abstract: A new cannabimimetic phenylacetylindole (cannabipiperidiethanone, 1) has been found as an adulterant in a herbal product which contains two other known synthetic cannabinoids, JWH-122 and JWH-081, and which is distributed illegally in Japan. The identification was based on analyses using GC-MS, LC-MS, high-resolution MS and NMR. Accurate mass spectrum measurement showed the protonated molecular ion peak of 1 at m/z 377.2233 [M+H]+ and the molecular formula of 1 was C24H29N2O2. Both mass and NMR spectrometric data revealed that 1 was 2-(2-methoxyphenyl)-1-{1-[(1-methylpiperidin-2-yl)methyl]-1H-indol-3-yl}ethanone. Compound 1 has a mixed structure of known cannabimimetic compounds: JWH-250 and AM-2233. Namely, the moiety of phenylacetyl indole and N-methylpiperidin-2-yl-methyl correspond to the structure of JWH-250 and AM-2233, respectively. However, no synthetic, chemical or biological information about 1 has been reported. A binding assay of compound 1 to cannabinoid receptors revealed that 1 has affinity for the CB1 and CB2 (IC50=591, 968 nM, respectively) receptors, and shows 2.3- and 9.4-fold lower affinities than those of JWH-250. This is the first report to identify cannabimimetic compound (1) as a designer drug and to show its binding affinity to cannabinoid receptors.
60 citations
TL;DR: It is found that the Tat analog and AT1002 strongly increased siRNA stability against RNaseA, and combination of Tat and AT 1002 is expected to be a transdermal delivery enhancer of siRNA.
Abstract: Topical use of small interfering RNA (siRNA) as a therapeutic nucleic acid is increasingly studied for the treatment of skin diseases and for the improvement of skin properties. However, naked siRNA transdermal delivery is limited by its low stability in the body and low permeability into target cells. This is due to various skin barriers such as the stratum corneum that has multiple lipid bilayers and epidermal layers that have tight junctions. In this study, we investigate non-invasive transdermal siRNA delivery using two functional peptides: AT1002, which is a tight junction modulator and 6-mer synthetic peptide belonging to a novel class of compounds that reversibly increases paracellular transport of molecules across the epithelial barrier; and Tat, which is a cell-penetrating peptide applicable as a transdermal siRNA delivery enhancer. We examined whether expression of the tight junction protein zonula occludens protein 1 (ZO-1) was detected in mouse skin applied with AT1002. Additionally, siRNA stabilities for RNaseA using Tat and AT1002 were assessed. We also determined the intradermal delivery efficiency of siRNA using functional peptides by confocal laser microscopy of fluorescently labeled siRNA in mouse skin. We found that the Tat analog and AT1002 strongly increased siRNA stability against RNaseA. In addition, ZO-1 disappeared from the skin after treatment with AT1002, yet recovered with time after washing. Finally, we also found that Tat and AT1002 peptides accelerate transdermal siRNA delivery both widely and effectively. Thus, combination of Tat and AT1002 is expected to be a transdermal delivery enhancer of siRNA.
60 citations
TL;DR: NLCs can potentially be exploited as a drug carrier for topical or intravenous use in the future and show the sustained release of tryptanthrin without an initial burst.
Abstract: Tryptanthrin is an ancient medicine which recently was also found to have a function of downregulating multidrug resistance (MDR). However, tryptanthrin is insoluble in water, which limits its availability for delivery into cancer cells. There is a need to improve delivery systems to increase the inhibition of MDR. The aim of this study was to employ nanoparticles encapsulating tryptanthrin to improve the delivery and promote the sustained release of this drug. The approach was to encapsulate tryptanthrin in various nanoparticles, including solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), and lipid emulsions (LEs). We compared the particle size and zeta potential of these nanoparticles, and evaluated the partitioning behavior of tryptanthrin in them. We also determined the release kinetics of tryptanthrin from these nanoparticles. Moreover, cellular cytotoxicity toward and uptake of tryptanthrin-loaded nanoparticles by human breast cancer cells were determined. We found that the mean particle size of NLCs was lower, and the partition coefficient was higher than those of SLNs, and an increased tryptanthrin release rate was found with the NLC delivery system. NLCs achieved the sustained release of tryptanthrin without an initial burst. In particular, the NLC-C formulation, composed of a mixture of Compritol and squalene as the core materials, showed the highest release rate and cytotoxic effect. Confocal laser scanning microscopic images confirmed drug internalization into cells which enhanced the endocytosis of the particles. These results suggested that NLCs can potentially be exploited as a drug carrier for topical or intravenous use in the future.
56 citations
TL;DR: The findings indicate the potential use of hydrophilic chlorogenic acid with o/w-type microemulsion as a vehicle to protect skin against UV-induced oxidative damage.
Abstract: We examined the intradermal delivery of a hydrophilic polyphenol chlorogenic acid by in vitro study using excised guinea pig dorsal skin and Yucatan micropig skin. Skin accumulation as well as the solubility of chlorogenic acid in aqueous vehicles was much greater than for other polyphenols such as quercetin and genistein. However, since enhancement of skin delivery seemed to be necessary to exhibit its protective effects against oxidative damage of skin, we examined the effects of microemulsions as vehicles. Using microemulsions consisting of 150 mM NaCl solution, isopropyl myristate, polyoxyethylene sorbitan monooleate (Tween 80) and ethanol, skin accumulation as well as solubility of chlorogenic acid further increased. Enhancement effect of an oil-in-water (o/w-type) microemulsion was greater than that of a water-in-oil (w/o-type) microemulsion possibly due to the greater increase in solubility. This finding was quite different from previous findings on relatively hydrophobic polyphenols such as quercetin and genistein. Pretreatment of guinea pig dorsal skin with chlorogenic acid containing microemulsion gel prevented erythema formation induced by UV irradiation. These findings indicate the potential use of hydrophilic chlorogenic acid with o/w-type microemulsion as a vehicle to protect skin against UV-induced oxidative damage.
54 citations
TL;DR: From the embryos of the seeds of Nelumbo nucifera, three bisbenzylisoquinoline alkaloids, nelUMoferine and nelumborines A and B, were isolated along with four known compounds, neferine, liensinine, isoliensinine and anisic acid.
Abstract: From the embryos of the seeds of Nelumbo nucifera, three bisbenzylisoquinoline alkaloids, nelumboferine and nelumborines A and B, were isolated along with four known compounds, neferine, liensinine, isoliensinine and anisic acid. The structures of the new alkaloids were determined mainly by spectroscopic methods.
53 citations
TL;DR: Some herbal alkaloids like harmine, in spite of lacking antioxidative property, have potential as anti-inflammatory agents that strongly suppress TNF-α and NO production by a unique mechanism.
Abstract: It is beneficial to treat chronic inflammatory condition in patients through diets that inhibit the production of proinflammatory cytokines and mediators such as tumor necrosis factor-α (TNF-α) and nitric oxide (NO). Since less attention has been paid to alkaloids in the diets than to polyphenols in this regard, we aimed at investigating anti-inflammatory activity of herb-derived alkaloids through suppression of TNF-α and NO production in lipopolysaccharide (LPS)-stimulated mouse RAW264 and/or human THP-1 cells. A harmala alkaloid, harmine, an opium alkaloid, papaverine, and Lycoris alkaloids, lycorine and lycoricidinol, showed TNF-α suppressive activities stronger than or comparable to that of a reference polyphenol, butein, in RAW264 cells (IC(50)=4, 10, 2.1, 0.02, and 8 µM, respectively). Other alkaloids showed no or marginal to moderate inhibitory activities. Similar tendency of inhibition was found for NO production in RAW264 cells and TNF-α production in THP-1 cells. In addition, harmine was found to suppress interleukin-6 (IL-6) production in RAW264 cells. The above four inhibitory alkaloids had essentially no antioxidative property in the superoxide anion scavenging assay. Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) showed that harmine caused neither prevention of nuclear factor-κB (NF-κB) translocation into the nucleus nor inhibition of p38 mitogen activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) phosphorylation, while that the LPS-induced transcription of TNF-α and inducible NO synthase was dose-dependently attenuated by harmine. This result suggests that the molecular mechanism of harmine action is different from those of many other anti-inflammatory phytochemicals. In conclusion, some herbal alkaloids like harmine, in spite of lacking antioxidative property, have potential as anti-inflammatory agents that strongly suppress TNF-α and NO production by a unique mechanism.
TL;DR: Two natural antioxidants were isolated from the methanolic extract of the fruit bodies of Inonotus hispidus and exhibited significant scavenging activity against the 2,20-azinobis(3-ethylbenzhiazoline-6-sulfonate) radical cation and showed moderate cytotoxicity against a human breast carcinoma cell line.
Abstract: Two natural antioxidants, named inonotusin A (1) and B (2), were isolated from the methanolic extract of the fruit bodies of Inonotus hispidus, together with (E)-4-(3,4-dihydroxyphenyl)but-3-en-2-one (3), hispidin (4) and 3,4-dihydroxybenzaldehyde (5). Their structures were identified by means of extensive NMR and MS data analysis. Compounds 1, 2 and 4 exhibited significant scavenging activity against the 2,20-azinobis(3-ethylbenzhiazoline-6-sulfonate) (ABTS) radical cation. Compound 1 also showed moderate cytotoxicity against a human breast carcinoma cell line (MCF-7) with IC(50) values of 19.6 µM.
TL;DR: Embelin and both of its derivatives almost completely abolished the acetic acid induced writhing and p-Sulfonylamine phenylamino derivative showed better anti-inflammatory activity than embelin.
Abstract: Antioxidant and related properties of the plant Embelia ribes and embelin are well known. In the present study embelin was condensed with various aromatic substituted primary amines to yield ten new and one reported derivatives along with monomethyl embelin. All these compounds along with embelin were evaluated for in vitro antioxidant activity using 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) and 2,2'-diphenyl-1-picryl hydrazyl (DPPH) methods. Two para-substituted embelin derivatives showed potent antioxidant activity. These compounds along with embelin were studied for analgesic and anti-inflammatory activities at 10 and 20 mg/kg doses by standard methods. Potent analgesic activity higher than the standard pentazocine was observed. Embelin and both of its derivatives almost completely abolished the acetic acid induced writhing. p-Sulfonylamine phenylamino derivative showed better anti-inflammatory activity than embelin.
TL;DR: The prepared solid dispersions showed remarkable increase in solubility, dissolution rate and hence bioavailability of poorly water soluble drug Irbesartan.
Abstract: The objective of present work was to enhance the solubility and bioavailability of poorly aqueous soluble drug Irbesartan (IBS). The solid dispersions were prepared by spray drying method using low viscosity grade HPMC E5LV. Prepared solid dispersions were characterized by dissolution study, fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction studies (XRD). Results of the SEM, DSC and XRD study showed the conversion of crystalline form of IBS to amorphous form. The dissolution rate was remarkably increased in case of solid dispersion compared to pure IBS. Solubility and stability of solid dispersion was increased due to surfactant and wetting property, slowing devitrification and having anti-plasticization effect of HPMC E5LV. In vivo studies were performed in healthy rabbits (New Zealand grey) and compared with plain IBS. Solid dispersions showed increase in relative bioavailability than the plain IBS suspension. In conclusion, the prepared solid dispersions showed remarkable increase in solubility, dissolution rate and hence bioavailabilty of poorly water soluble drug Irbesartan.
TL;DR: Chitosan nanoparticles loaded with antineoplastic drug Lomustine greatly inhibited the growth of the L132 cancer cell line used in this study in comparison to the native LMT.
Abstract: The aim of this work was to prepare chitosan nanoparticles loaded with antineoplastic drug Lomustine (LCNPs), by ionic-gelation method with homogenization. The nanoparticles were characterized for particle size, polydispersity index (PDI), surface morphology, encapsulation efficiency, in-vitro drug release and cytotoxicity on human lung cancer cell line L132 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The particle size, zeta potential and encapsulation efficiency of prepared nanoparticles ranged from 75 ± 1.1 to 637 ± 1.6 nm (PDI from 0.05 ± 0.001 to 0.18 ± 0.007), 37.2 ± 0.21 to 53.8 ± 0.18 mV and 66.74 ± 1.4 to 98.0 ± 1.8% respectively. The particles were spherical in shape with smooth surface in scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. Mechanical shearing by homogenization treatment significantly changed the nanoparticle size. The drug release rate was biphasic and diffusion controlled over the 8 h. LCNPs greatly inhibited the growth of the L132 cancer cell line used in this study in comparison to the native Lomustine (LMT).
TL;DR: During further chemical and biological investigations of Picrasma quassioides BENNET, four new bis-β-carboline alkaloid alkaloids, quassidines E-H (1-4), and three new β-carbolines (5) and canthin-16-one-14-butyric acid (5), 3-(1,1-dimethoxylmethyl)-β- carboline (6), and 6,12-Dimethoxy
Abstract: During further chemical and biological investigations of Picrasma quassioides BENNET, four new bis-β-carboline alkaloids, quassidines E—H (1—4), and three new β-carboline alkaloids, canthin-16-one-14-butyric acid (5), 3-(1,1-dimethoxylmethyl)-β-carboline (6), and 6,12-dimethoxy-3-formyl-β-carboline (7), were isolated from its anti-inflammatory CHCl3-soluble fraction. Structures of new compounds were elucidated and characterized by MS and NMR analysis. A plausible biogenetic pathway for quassidine E (1), the first bis-β-carboline alkaloid in which a canthin-6-one moiety and a β-carboline moiety were connected together by a single carbon–carbon bond from the nature, was proposed. Quassidines E—G (1—3) showed potent inhibitory activity on the production of nitric oxide (NO), tumor necrosis factor α (TNF-α), or interleukin 6 (IL-6) in mouse monocyte-macrophage RAW264.7 cells stimulated by lipopolysaccharide (LPS). Analysis of anti-inflammatory activity of all β-carboline and bis-β-carboline alkaloids from P. quassioides showed that the carbonyl groups or double carbon–carbon bonds at C-14 for β-carbolines and C-14′ for bis-β-carbolines were bioactive groups for their in vitro anti-inflammatory activity. Structure–activity relationship of these compounds on inhibitory activity of the three inflammatory cytokines was discussed.
TL;DR: Five new drimane sesquiterpenes together with 14 known analogues were isolated from laboratory cultures of a mangrove-derived fungus Aspergillus ustus and antitumor activities were evaluated by sulforhodamine B and MTT methods.
Abstract: Five new drimane sesquiterpenes (1-5) together with 14 known analogues (6-19) were isolated from laboratory cultures of a mangrove-derived fungus Aspergillus ustus. Their structures were established by spectroscopic methods and antitumor activities were evaluated by sulforhodamine B (SRB) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods.
TL;DR: Flavusides A and B and two new antibacterial cerebroside derivatives have been isolated from the extract of a marine isolate of the fungus Aspergillus flavus and the structure and absolute stereochemistry of two cerebrosides were assigned on the basis of NMR and Tandem FAB-MS/MS experiments.
Abstract: Flavusides A (1) and B (2), two new antibacterial cerebroside derivatives, and the previously described phomaligol A (3), kojic acid (4), methyl kojic acid (5), and dimethyl kojic acid (6) have been isolated from the extract of a marine isolate of the fungus Aspergillus flavus. The structure and absolute stereochemistry of two cerebrosides were assigned on the basis of NMR and Tandem FAB-MS/MS experiments. Compounds 1, 2, and 3 exhibited a mild antibacterial activity against Staphylococcus aureus, methicillin-resistant S. aureus, and multidrug-resistant S. aureus. The minimum inhibitory concentration (MIC) values for each strain are as follows: compounds 1 and 2 showed 15.6 μg/ml for S. aureus and 31.2 μg/ml for methicillin-resistant S. aureus and multidrug-resistant S. aureus, and compound 3 exhibited 31.2 μg/ml for S. aureus and methicillin-resistant S. aureus and 62.5 μg/ml for multidrug-resistant S. aureus.
TL;DR: A new series of 2-arylidenehydrazinyl-4-arylthiazole derivatives (2a-k) was designed and synthesized through a rapid, simple, and efficient methodology in excellent isolated yield and a good qualitative correlation between predicted lipophilic parameters and antibacterial activity has been found.
Abstract: A new series of 2-arylidenehydrazinyl-4-arylthiazole derivatives (2a—k) was designed and synthesized through a rapid, simple, and efficient methodology in excellent isolated yield. These compounds were screened for in vitro antimicrobial activities against eight bacteria, e.g. Bacillus cereus, Staphylococcus aureus, Bacillus subtilis, Bacillus megaterium, Pseudomonas aeruginosa, Shigella dysenteriae, Salmonella typhi, Escherichia coli, and three fungi e.g. Aspergillus oryzae, Candida albicans, and Saccharomyces cerevis. The results indicate that some of the compounds exhibit strong antibacterial activity, depending on the bacterial strain, but show virtually no antifungal activity. The structure‐antibacterial activity relationships were studied using some physicochemical and quantum-chemical parameters with the ab initio Hartree‐Fock model at the RHF/6-31G level of theory. A good qualitative correlation between predicted lipophilic parameters and antibacterial activity has been found.
TL;DR: Results indicate that the fresh Rehmanniae radix is rich in polysaccharides, which are hydrolyzed during the processing, and the number and signal intensity of the smaller glycosides were increased.
Abstract: The processing of biological raw materials is considered to have an important role in the therapeutic application in Traditional Chinese Medicine. The root of Rehmannia glutinosa has to be processed by nine cycles of rice wine immersing, steaming and drying before using in clinical applications. In order to understand the chemical changes resulting from the processing, a comprehensive analysis of Rehmanniae radix was made using 1HNMR and Fourier transform (FT)-mass spectrometry in combination with multivariate data analysis. After 1HNMR and principle component analysis, hydrolysis was found to be the major chemical process during the treatments. Catalpol, raffinose and stachyose levels gradually decreased during processing, whereas monosaccharides including galactose and glucose were found to be higher in processed roots. The metabolic profile changed gradually through the processing cycles although the differences became smaller after the fifth processing cycle. The positive and negative ion-mode mass spectra by high resolution FT-MS revealed several series of ion clusters with mass differences of 162.053 Da, indicating a difference of a hexose moiety. During the processing, the number and signal intensity of the smaller glycosides were increased. Therefore, these results indicate that the fresh Rehmanniae radix is rich in polysaccharides, which are hydrolyzed during the processing. © 2011 Pharmaceutical Society of Japan.
TL;DR: It was found that the dissolution rate of the nanocrystal formulations increased and although tablet formulations which did not contain any solubilizing agent like sodium lauryl sulfate (SDS), the dissolution profile of these formulations were found similar to the commercial product.
Abstract: Ezetimibe is a lipid-lowering compound that selectively inhibits the absorption of cholesterol and related phytosterols from the intestine. As ezetimibe is almost insoluble in water, its bioavailability is too low to be detected. Thus, the objective of this study was to improve the solubility and dissolution rate of ezetimibe by preparing drug nanocrystals utilizing ball milling, high speed homogenization techniques. Pluronic F127 was chosen as a surface modifier to stabilize the nanocrystal formulations. Nanocrystal formulations of ezetimibe were prepared by using ball milling and high speed homogenization techniques. Additionally, the physicochemical characteristics of ezetimibe and nanocrystal formulations were determined by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X-ray analysis and particle size analysis. Tablets were prepared containing ezetimibe nanocrystals formed by high speed homogenization (ultrasonic) and ball milling according to the results of particle size measurements and in vitro dissolution rates of the nanocrystal formulations. As a result of these experiments, it was found that the dissolution rate of the nanocrystal formulations increased and although tablet formulations which did not contain any solubilizing agent like sodium lauryl sulfate (SDS), the dissolution profile of these formulations were found similar to the commercial product.
TL;DR: Observations suggest that compounds 1 and 2 may be involved in regulation of programmed death in the initiation and propagation of inflammatory responses inThe petroleum ether extract of the red alga Laurencia obtusa afforded three new C(15) acetogenins, which had no inhibition of apoptosis but apoptosis was enhanced significantly by aging.
Abstract: The petroleum ether extract of the red alga Laurencia obtusa afforded three new C15 acetogenins (cyclic ether enyne): (12Z)-cis-maneonene-D (1), (12E)-cis-maneonene-E (2), and (12Z)-trans-maneonene-C (3), along with one known cis-maneonene-A (4). Blood neutrophils were prepared, cultured, and incubated for 24, 48, and 72 h in medium with and without isolated compounds. Blood neutrophils were prepared, cultured, and incubated for 24, 48 and 72 h in medium with and without the isolated compounds. Both morphology and DNA fragmentation methods assessed the percentage of neutrophils apoptosis in each culture. In the present study, several observations have been made concerning the apoptosis-inducing or inhibiting effect of 1 and 2. Both compounds had no inhibition of apoptosis but apoptosis was enhanced significantly by aging. However, 1 stimulated apoptosis of normal only at the initial 24 h. After that there was no significant difference in apoptosis with or without compound 1, while 2 stimulated apoptosis at all the times. The apoptosis induced by these two compounds was demonstrated by DNA fragmentation assay and microscopic observation. These observations suggest that compounds 1 and 2 may be involved in regulation of programmed death in the initiation and propagation of inflammatory responses.
TL;DR: Three new citrinin derivatives, penicitrinols C, D, and E (1-3), along with two known compounds,citrinin (4) and decarboxydihydrocitrinone (5), were isolated from Penicillium citrinum and demonstrated weak cytotoxicity against the HL-60 cell line.
Abstract: Three new citrinin derivatives, penicitrinols C, D, and E (1-3), along with two known compounds, citrinin (4) and decarboxydihydrocitrinone (5), were isolated from Penicillium citrinum. Their structures were determined by spectroscopic methods and X-ray diffraction analysis. Compounds 1 and 3 demonstrated weak cytotoxicity against the HL-60 cell line.
TL;DR: Two new cannabinoid-like chromane and chromene derivatives named anthopogocyclolic acid andAnthopogochromenic acid and five related compounds, which are known as synthetic analogues of cannabinoids, have been isolated together with geranyl orsellinic acid from the Chinese medicinal plant Rhododendron Anthopogonoides.
Abstract: Two new cannabinoid-like chromane and chromene derivatives named anthopogocyclolic acid (1) and anthopogochromenic acid (2) and five related compounds (3-7) which are known as synthetic analogues of cannabinoids: cannabichromene (CBC) type, cannabicyclol (CBL) type, and cannabicitran (CBT) type, have been isolated together with geranyl orsellinic acid (8) from the Chinese medicinal plant Rhododendron anthopogonoides. Their structures were elucidated based on spectroscopic and chemical evidence. The absolute configuration of the asymmetric carbons at C-2 of 1-7 was determined to be S from their circular dichroism (CD) spectra. Compounds 2, 4 and 6 inhibited compound 48/80-induced histamine release from rat peritoneal mast cells.
TL;DR: The optimized formulation was found to be stable and bioequivalent with Suminat® and found to have a pleasant taste and mouth feel and disintegrated in the oral cavity within 41 s in human volunteers.
Abstract: The aims of the present research were to mask the intensely bitter taste of sumatriptan succinate and to formulate orally disintegrating tablets (ODTs) of the taste masked drug Taste masking was performed by coating sumatriptan succinate with Eudragit EPO using spray drying technique The resultant microspheres were evaluated for thermal analysis, yield, particle size, entrapment efficiency and in vitro taste masking The tablets were formulated by mixing the taste masked microspheres with different types and concentrations of superdisintegrants and compressed using direct compression method followed by sublimation technique The prepared tablets were evaluated for weight variation, thickness, hardness, friability, drug content, water content, in vitro disintegration time and in vitro drug release All the tablet formulations disintegrated in vitro within 37-410 s The optimized formulation containing 5% Kollidon CL-SF released more than 90% of the drug within 15 min and the release was comparable to that of commercial product (Suminat®) In human volunteers, the optimized formulation was found to have a pleasant taste and mouth feel and disintegrated in the oral cavity within 41 s The optimized formulation was found to be stable and bioequivalent with Suminat®
TL;DR: Two new flavonoid glycosides, (1, 2), and eleven known compounds, (3-13), were isolated from from a 70% EtOH extract of the leaves of Chromolaena odorata (Asteraceae) by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies.
Abstract: Two new flavonoid glycosides, (1, 2), and eleven known compounds, (3-13), were isolated from from a 70% EtOH extract of the leaves of Chromolaena odorata (Asteraceae). Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The newly isolated compounds were tested in vitro for their cytotoxic activities against the LLC and HL-60 cancer cell lines. Compound 1 showed cytotoxicity against LLC and HL-60 cancer cell lines with IC(50) values of 28.2 and 11.6 µM, respectively. Compound 2 exhibited significant cytotoxic activity in the inhibition of HL-60 cancer cell lines with IC(50) value of 10.8 µM.
TL;DR: The design, synthesis, and evaluation of novel thieno[2,3-d]pyrimidin-4-yl hydrazone analogues as cyclin-dependent kinase 4 (CDK4) inhibitors are described and compound 35 has been identified with efficacy in a xenograft model of HCT116 cells.
Abstract: The design, synthesis, and evaluation of novel thieno[2,3-d]pyrimidin-4-yl hydrazone analogues as cyclin-dependent kinase 4 (CDK4) inhibitors are described. In continuing our program aim to search for potent CDK4 inhibitors, the introduction of a thiazole group at the hydrazone part has led to marked enhancement of chemical stability. Furthermore, by focusing on the optimization at the C-4′ position of the thiazole ring and the C-6 position of the thieno[2,3-d]pyrimidine moiety, compound 35 has been identified with efficacy in a xenograft model of HCT116 cells. In this paper, the potency, selectivity profile, and structure–activity relationships of our synthetic compounds are discussed.
TL;DR: Solid state characterization indicated that there is no interaction between ketoconazole and nicotinamide in the solid state.
Abstract: Purpose: The aim of the present study was to improve the solubility and dissolution rate of a poorly water-soluble drug ketoconazole using solid dispersion technique. Methods: Solid dispersions of ketoconazole were prepared in ratios of 90 : 10, 70 : 30, 50 : 50, 30 : 70 and 10 : 90 by the melting method using nicotinamide as carrier. These solid dispersions were characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy to ascertain if there were any physicochemical interactions between drug and carrier that could affect dissolution. Solubility and dissolution studies were conducted with pure ketoconazole, physical mixtures and solid dispersions. Results: Solubility studies indicated that nicotinamide increased significantly the solubility of ketoconazole in water. The Gibbs free energy (ΔG°tr) values were negative indicating the spontaneous nature of ketoconazole solubilization, and it decreased with increase in concentration of the carrier, demonstrating that the reaction became more favorable as the concentration of the carrier increased. The cumulative release of ketoconazole within 120 min from solid dispersion at a drug-to-nicotinamide ratio of 10 : 90 (w/w) was 6 times higher than the pure drug in phosphate buffer of pH 6.8. Conclusion: Solid state characterization indicated that there is no interaction between ketoconazole and nicotinamide in the solid state. In contrast to the very slow dissolution rate of pure ketoconazole, the dispersion of the drug in nicotinamide considerably enhanced the dissolution rate. The drug dissolution rate was highest at a drug-to-nicotinamide ratio of 10 : 90 (w/w).
TL;DR: Treatment of epigallocatechin gallate with copper(II) chloride efficiently afforded an unstable quinone dimer, dehydrotheasinens in A, and subsequent treatment with ascorbic acid stereoselectively yielded theasinensin A, one of the major polyphenols found in black tea.
Abstract: Chromatographic separation of black tea polyphenols is too difficult to supply sufficient quantities of pure compounds for biological experiments. Thus, facile methods to prepare black tea constituents were desired. Treatment of epigallocatechin gallate with copper(II) chloride efficiently afforded an unstable quinone dimer, dehydrotheasinensin A, and subsequent treatment with ascorbic acid stereoselectively yielded theasinensin A. The latter is a dimer with an R-biphenyl bond, one of the major polyphenols found in black tea. The method is simpler and more effective than enzymatic preparation.
TL;DR: According to these results, mucoadhesive vaginal tablet formulations prepared with PAA-Cys represent good example for delivery systems which prolong the residence time of drugs at the vaginal mucosal surface.
Abstract: The main objective of this work was to develop antifungal matrix tablet for vaginal applications using mucoadhesive thiolated polymer. Econazole nitrate (EN) and miconazole nitrate (MN) were used as antifungal drugs to prepare the vaginal tablet formulations. Thiolated poly(acrylic acid)-cysteine (PAA-Cys) conjugate was synthesized by the covalent attachment of L-cysteine to PAA with the formation of amide bonds between the primary amino group of L-cysteine and the carboxylic acid group of the polymer. Vaginal mucoadhesive matrix tablets were prepared by direct compression technique. The investigation focused on the influence of modified polymer on water uptake behavior, mucoadhesive property and release rate of drug. Thiolated polymer increased the water uptake ratio and mucoadhesive property of the formulations. A new simple dissolution technique was developed to simulate the vaginal environment for the evaluation of release behavior of vaginal tablets. In this technique, daily production amount and rate of the vaginal fluid was used without any rotational movement. The drug release was found to be slower from PAA-Cys compared to that from PAA formulations. The similarity study results confirmed that the difference in particle size of EN and MN did not affect their release profile. The release process was described by plotting the fraction released drug versus time and n fitting data to the simple exponential model: M(t)/M(∞)=kt(n). The release kinetics were determined as Super Case II for all the formulations prepared with PAA or PAA-Cys. According to these results the mucoadhesive vaginal tablet formulations prepared with PAA-Cys represent good example for delivery systems which prolong the residence time of drugs at the vaginal mucosal surface.