In continuing our program aimed to search for potent drugs for bacterial infections, a series of 3-(4-halophenyl)-3-oxopropanal and their derivatives were designed, synthesized and their antibacterial activities in vitro against both Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa were evaluated. Compounds 7, 8, 13—16, 21 and 22 had moderate antibacterial activities against Staphylococcus aureus (minimal inhibitory concentration (MIC) <16 μg/ml), suggesting that the introduction of mono-methoxyamine or ethoxyamine moiety might play an important role in determining the potent antibacterial activities. Furthermore, the antibacterial activities of select compounds 7, 15 and 16 against the clinically important pathogenic bacteria-methicillin-resistant Staphylococcus aureus (MRSA) were also investigated. Results showed that these compounds exhibited more potent activities than the well-known antibacterial agents Houttuynin and Levofloxacin.

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The solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water at 25 °C are reported. The generated data are fitted to the Jouyban–Acree model and the mean relative deviations are 2.6%, 1.5%, 5.8%, and 7.4%, respectively for ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water.

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We designed a single unit type controlled release tablet containing nateglinide to decrease both postprandial blood glucose level (PBG) and fasting blood glucose level (FBG) in normal beagle dogs. The tablet contains 60 mg of nateglinide in an immediate release portion, and 90 mg of nateglinide in a controlled release portion. Compressionable enteric coated granules were selected as the controlled release portion to primarily decrease FBG, and they were prepared by an aqueous coating with Eudragit^®. Three types of nateglinide controlled release tablets were obtained, and their weights were 418.1—425.1 mg/tablet containing the above compressionable enteric coated granules. Even after tableting, the dissolution behavior of enteric coated granules was maintained approximately. In vivo single oral administration studies using normal male beagle dogs demonstrated that these tablets were able to decrease both PBG and FBG. The relative bioavailability values of the obtained tablets containing enteric coated granules having a dissolution pH of 6.0 and 6.8 were estimated at about 57.2 and 60.8% respectively against nateglinide immediate release tablets. In an in vivo repeated administration study with the tablets containing enteric coated granules having a dissolution pH of 6.8 (an interval: 8 h), decreases in both PBG and FBG were observed continuously twice. On the basis of the above results, it is expected to enable control of both PBG and FBG for moderate and severe diabetes patients with a controlled release formulation containing a short-acting type oral blood glucose regulator, not only nateglinide but also meglitinides (repaglinide, mitiglinide, etc.).

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A thermoreversible gelation polymer consisting of an aqueous solution in the sol state at room temperature and in the gel state near body temperature was examined for its use in the retention of microspheres and sustained, long-term delivery of anti-cancer drugs using a rat model of malignant glioma. The poly(lactic-co-glycolic acid) (PLGA) microspheres containing camptothecin at ratios of 1 : 33 or 1 : 50 mediated sustained release, with approximate 80% of camptothecin released after 28 d. Rats were inoculated in the brain with C6 glioma cells, followed 7 d later by injection in the tumor site with 1 : 33 and 1 : 50 PLGA microspheres dispersed in a thermoreversible gelation polymer (TGP) solution. Kaplan–Meier analysis showed that the mean survival period of the untreated group was 16 d, with a slight increase in rats treated with TGP-only solution, empty or 1 : 50 microspheres in phosphate-buffered saline. The mean survival period of rats treated with the camptothecin powder in TGP was 21 d, while that of rats treated with 1 : 33 and 1 : 50 microspheres in TGP was significantly longer than the untreated group; long-term survival rats were observed. These results suggest that the anti-tumor effect of camptothecin can be enhanced by long-term sustained release from microspheres retained in the rat brain by TGP gel.

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Synthesis of furochromone, 2-phenylchromone (flavone) and benzofuran derivatives substituted with thiosemicarbazide or thiazolidin-4-one moieties were accomplished. All the newly synthesized compounds were tested for their anticonvulsant activity in both subcutaneous pentylenetetrazole induced seizures (scPTZ) and maximal electric shock induced seizures (MES) tests using valproic acid and phenytoin respectively as reference standards. The most active compounds in scPTZ model were 1c, 2b, 5a and 7e showing 100% protection at 300 mg/kg upon intraperitoneal administration. Also, the effect of pre-treatment of three of the most active compounds (1c, 2b, 5a) on 4-amino pyridine-induced lethality in mice was investigated. Pre-treatment with these compounds significantly increased the latency for clonic and tonic seizures and prevented 4-amino pyridine induced death. Hence, this provides evidence for anticonvulsant activity of these compounds, and a neuroprotective activity for them. The structure–activity relationship was studied based on the obtained data.

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An economical new process has been developed for the synthesis of donepezil hydrochloride (1) an anti-Alzheimer's drug. The process involves Darzen reaction of pyridine-4-carboxaldehyde and 2-bromo-5,6-dimethoxy indanone affording epoxide 5,6-dimethoxy-3-(pyridine-4-yl)spiro[indene-2,2′-oxiran]-1(3H)-one (4) as a key intermediate. The one-pot deoxygenation of 4 and hydrogenation of the aryl moiety in high yield improved the overall yield of the process.

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Atorvastatin is commonly used as a cholesterol lowering agent in patients. Recently, the neuroprotective effects of atorvastatin became the focus of many research studies. In this study, we have formulated chitosan microspheres containing atorvastatin calcium. In-vitro characterization of chitosan microspheres and quantification of atorvastatin calcium from formulations were also evaluated. The neuroprotective efficiency of atorvastatin calcium was investigated by an experimental spinal cord injury model. Atorvastatin calcium microspheres were implanted at the laminectomy area (1 mg/kg) immediately after trauma. Twenty-four hours after injury, motor functions of animals were scored according to modified Tarlov Scale. In spinal cord tissues tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and lipid peroxidation levels were quantified and ultrastructural changes have been investigated. The results of all parameters indicate that microspheres containing atorvastatin calcium were capable of improving functional outcome, attenuating the expression of TNF-α, IL-1β and IL-6; lowering lipid peroxidation levels and maintaining the preservation of the cellular uniformity.

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The aim of the present study was to prepare mucoadhesive multiparticulate system for oral drug delivery using ionic gelation technique. Microspheres of different mucoadhesive polymers including hydroxypropyl methylcellulose (HPMC) K15M and carbopol 971P were prepared. In this technique cross linking of sodium alginate with calcium chloride was done which retarded the release of drug from the mucoadhesive polymer. In the present work atenolol was used as model drug. Interaction studies performed using FT-IR spectroscopy revealed that there was no drug to polymer interactions. Multiparticulates so prepared were discrete, bulky, free flowing and showed an average encapsulation efficiency ranging from 23—74%. Particle size of the multiparticulates as determined by the scanning electron microscopic analysis (SEM) studies was found to be between 561—831 μm. The prepared formulations also exhibited a good mucoadhesive strength which was determined in in vitro conditions through falling film technique. The multiparticulate so prepared also exhibited a good swelling index which confirmed the strong mucoadhesive property of the formulation. Atenolol release from the multiparticulate system was regulated and extended until 12 h and exhibited a non-Fickian anomalous transport from the swellable microspheres, as evident from the release rate exponent values which varied between 0.569—0.622. The stability studies performed on the optimized batch at 40 °C/75% RH for 90 d indicated no significant change in the physicochemical properties. In vivo radioimaging studies in rabbits showed the residence of mucoadhesive microspheres for 6-8 h in upper part of gastrointestinal tract (GIT).

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Two new cyathane-type diterpenoids, nigernin A and B (1, 2), one new nitrogenous terphenyl derivative, phellodonin (3), together with three known compounds, 2′,3′-diacetoxy-3,4,5′,6′,4″-pentahydroxy-p-terphenyl, grifolin, and 4-O-methylgrifolic acid, were isolated from the fruiting bodies of basidiomycete Phellodon niger. The structures of these new compounds were elucidated by spectroscopic methods and comparison with the data of known compounds in the literature. All these compounds were isolated from this fungus for the first time.

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Propargylations of 1,3-diketones using 3-sulfanyl and 3-selanylpropargyl alcohols 1 in MeNO₂–H₂O gave alkynyl ketones 2a—m, 2o—v and 6,7-dihydro-5H-cyclohexa[b]pyran-5-ones 3k—n. With some bases, the useful propargylated 1,3-diketones underwent intramolecular cyclization to give 6,7-dihydro-5H-benzofuran-4-ones 4a—i or 4,5,6,7-tetrahydrobenzofurans 5p, 6p—v.

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P-Glycoprotein accounts for multidrug resistance in chemotherapy patients and contributes to reduced oral bioavailability and distribution of drugs in the brain. The aim of this study was to establish the qualitative and quantitative structure–activity relationships (QSAR) of flavonoid modulation effects on P-glycoprotein (P-gp)'s function. Using human colorectal adenocarcinoma (HCT15) cells as an in vitro model and fexofenadine as a P-gp substrate, the modulation effects on P-gp at three concentration levels of 22 representative compounds from four flavonoid families were evaluated. Results showed that the modulation (enhanced or inhibitory) effects could be divided into three ranges designated as enhanced (<100%) as compared to the control, low inhibitory (100—217%) and high inhibitory (>217%) as compared to verapamil. An optimal QSAR was constructed for Y1 (adjusted R²=0.4798), Y2 (adjusted R²=0.6809), and Y3 (adjusted R²=0.5902), respectively. This was further confirmed by a highly correlated plot of the predicted percent inhibition against observed values from a respective QSAR equation.

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Using thymopentin and insulin as the model protein–drugs, novel Gel-Core-solid lipid nanoparticle (SLN) with the hydrogel core and lipid shell were prepared by double emulsion and thermal sensitive gel technology, with the intention to improve the entrapment efficiency. Pluronic F127 and Glyceryl palmitostearate were selected as hydrogel material and lipid material, respectively. The particle sizes and zeta-potential were characterized by dynamic light scattering and electrophoretic light scattering. Transmission electron microscopy (TEM) was employed to investigate the structure of this Gel-Core-SLN. The Gel-Core-SLN was successfully prepared and the particle size was 305.2 nm with zeta potential of −17.15 mV. Observations by TEM confirmed that most solidified hydrogel particles were dispersed in the central of Gel-Core-SLN as a form of single core, which effectively prevented the diffusion of proteins to the external water phase during preparation process. The entrapment efficiency of thymopentin-loaded Gel-Core-SLN and insulin-loaded Gel-Core-SLN were 61.97% and 57.36%, respectively. Both the two drug-loaded Gel-Core-SLNs showed relatively low burst release. The pharmacological availability of insulin-loaded Gel-Core-SLN was 6.02%. It was suggested that the Gel-Core-SLN could be a promising drug delivery system with the outstanding encapsulation efficiency, low burst release and relatively high pharmacological availability.

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Four new cembrane diterpenes (1—4) and fifteen known cembranoids (5—19) were isolated from an Okinawan soft coral Lobophytum crassum. The structures of these four new cembranoids were determined on the basis of spectroscopic evidence. In particular, the absolute stereochemistry of 1, 2, 5 and 6 were elucidated by the application of the modified Mosher's method and circular dichroism (CD) spectral data. The inhibitory effects of some isolates were evaluated on nitric oxide (NO) production against a murine macrophage-like cell line (Raw 264.7). Cembranoids consisting of α-methylene-γ-lactone, exhibited the significant effect on NO production.

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Fibroblast growth factor 2 (FGF2) signaling plays an important role in angiogenesis. Heparin/heparan sulfate (HS) is required for FGF2 signaling but heparin mimics either promotes or inhibits FGF2 signaling. To take advantage such properties of heparin mimics, a series of N-heteroaroyl aminosaccharide derivatives were designed and synthesized as FGF2 signaling modulators. The bioactivity was determined in a FGF2 and heparin-dependent cell proliferation assay using FGFR1c expressing BaF3 cells. We found that most of the compounds inhibited heparin- and FGF2-dependent BaF3 cell proliferation while three compounds promoted the cell proliferation. These results suggest that the small molecular heparin mimics approach might be useful in developing novel anti-angiogenic agents.

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A series of difunctionalized 4-hydroxybenzaldehyde derivatives were designed, synthesized and evaluated as cholinesterase (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)) inhibitors. The results demonstrated that all the compounds had more potent AChE and BChE inhibitory activities than galanthamine-HBr, one of the best cholinesterase inhibitors known so far. The inhibition mechanism revealed that the best active compound 4e displayed a mix-type mode of AChE and BChE by its dual-site interactions with the catalytic triad active center and the peripheral anionic site (PAS) of enzyme. All these data suggested that further development of such compounds may be of interest.

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A new butenolide, aspernolide D (1), and furandione, asperterone (2), together with four known butenolides, butyrolactones I—IV and aspernolide B, were obtained from cultures of the endophytic fungus Aspergillus terreus, isolated from the flowering plant Mammea siamensis. The structures of these compounds were elucidated by analysis of NMR spectroscopic and mass spectrometric data.

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Two new drimane sesquiterpenoids, changweikangic acid A (1) and B (2), were isolated from Compound Changweikang. Their structures were established on basis of extensive spectroscopic analyses including two dimensional (2D) NMR and X-ray crystallographic data. The two compounds were evaluated for their inhibitory activity against nitric oxide production in lipopolysaccharide-activated macrophage cell line, RAW 264.7 cells.

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Three new stereoisomers of condensed tannins (1—3), and four known phenolic compounds (4—7) were isolated from the 80% acetone extract of the roots of Rosa multiflora Thunberg. The structures of these compounds were elucidated using 1D/2D NMR, high resolution (HR)-MS, and circular dichroism (CD) spectra. In order to evaluate their anti-oxidative and anti-inflammatory activities, their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and inhibitory activity on nitric oxide (NO) production were determined.

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Two new glycosidic acids, quamoclinic acids G and H, were isolated from the glycosidic acid fraction afforded by alkaline hydrolysis of the ether-insoluble resin glycoside (convolvulin) fraction from the seeds of Quamoclit pennata BOJER. Both compounds are the first examples of bisdesmosides of glycosidic acid having the sugar linkages at C-3 of 3,11-dihydroxytetradecanoic acid (ipurolic acid) as well as at its C-11.

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Activity-directed isolation of the ethyl acetate, methylene chloride and n-hexane fractions of Gloiopeltis furcata resulted in the isolation of 18 compounds. Their structures were elucidated as 2-(3-hydroxy-5-oxotetrahydrofuran-3-yl)acetic acid (1), glutaric acid (2), succinic acid (3), nicotinic acid (4), (E)-4-hydroxyhex-2-enoic acid (5), cholesterol (6), 7-hydroxycholesterol (7), uridine (8), glycerol (9), 5-(hydroxymethyl)-2-methoxybenzene-1,3-diol (10), (5E,7E)-9-oxodeca-5,7-dienoic acid (11), (Z)-3-ethylidene-4-methylpyrrolidine-2,5-dione (12), dehydrovomifoliol (13), loliolide (14), cholesteryl stearate (15), palmitic acid (16), cis-5,8,11,14,17-eicosapentaenoic acid (17) and α-linolenic acid (18) on the basis of spectroscopic and chemical evidences. Their anticholinesterase and antioxidant activities were evaluated via inhibitory activities on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) as well as scavenging activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and peroxynitrite (ONOO⁻). All isolated compounds (1—18) exhibited moderate AChE inhibitory activities with IC₅₀ values ranging from 1.14—12.50 μg/ml, whereas 1, 7, 9, 17, and 18 showed mild BChE inhibitory activities with IC₅₀ values ranging from 5.57—15.89 μg/ml. Although most of the compounds isolated were lacking the scavenging activity on DPPH radical and ONOO⁻, 5 and 10 showed good DPPH radical scavenging activity, and 5, 10, and 16 showed potent ONOO⁻ scavenging activity.

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A new 3β,5α,6β-trihydroxysteroid, bebryceoid A (1), has been isolated from an octocoral Bebryce sp. In addition, an octocoral Carijoa sp. yielded two new 3β,5α,6β-trihydroxysteroids, carijoids A (2) and B (3). The structures of steroids 1—3 were elucidated by spectroscopic methods and by comparison of the spectral data with those of known steroid analogues.

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Solid-state ¹³C nuclear magnetic resonance (¹³C-SSNMR) revealed significant differences in the chemical shift of specific carbon atoms between two fluconazole polymorphs, reflecting a change in molecular conformation. A single resonance signal without splitting was observed in the spectrum of anhydrate form II, while the spectrum of anhydrate form I showed signals with splitting, indicating the presence of two dissimilar molecular conformations in the unit cell of anhydrate form I. The Fourier transform infrared (FT-IR) and Raman spectra associated with the triazole group, the 2,4-difluorobenzyl group, and the propane backbone provided also evidence of structural differences between forms I and II accompanying with ¹³C-SSNMR. ¹H T₁ relaxation times, measured using saturation recovery experiments, showed that the metastable anhydrate form II was more mobile than the stable form I. The solubility and intrinsic dissolution tests showed that the anhydrate form II was more soluble and dissolved faster than the anhydrate form I.

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Four new triterpenoid saponins (1—4) were isolated from the rhizome of Ardisia gigantifolia STAPF. The structures of new saponins were established as 3β-o-α-L-rhamnopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl-16α-hydroxy-13,28-epoxy-oleanane (1), 3β-o-α-L-rhamnopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[β-D-glucopyrano-syl-(1→2)]-α-L-arabinopyranosyl-16α-hydroxy-13,28-epoxy-30-acetoxy-oleanane (2), 3β-o-α-L-rhamnopyranosyl-(1→3)-[β-D-glucopyranosyl-(1→4)-β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl-16α-hydroxy-13,28-epoxy-oleanane (3) and 3β-o-α-L-rhamnopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[β-D-6-O-acetylglucopranosyl-(1→2)]-α-L-arabinopyranosyl-16α-hydroxy-13,28-epoxy-oleanane (4) were isolated from Ardisia gigantifolia STAPF. Their structures were elucidated by means of ¹H- and ¹³C-NMR spectroscopic studies, including 2D-NMR technique. The cytotoxic activities of saponins 1—4 are reported against three human cancer cell lines, namely, Hela human cervical carcinoma cells, EJ human bladder tumor cells, and BCG-823 human gastric carcinoma cells.

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Glycogen synthase kinase 3β (GSK-3β) inhibitors are expected to be attractive therapeutic agents for the treatment of Alzheimer's disease (AD). Recently we discovered sulfoxides (S)-1 as a novel GSK-3β inhibitor having in vivo efficacy. We investigated practical asymmetric preparation methods for the scale-up synthesis of (S)-1. The highly enantioselective synthesis of (S)-1 (94% ee) was achieved by titanium-mediated oxidation with D-(−)-diethyl tartrate on gram scale.

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Site-selective cross-coupling of dihaloarenes constitutes a useful method for synthesis of multi-substituted arenes. In this paper, we report the site-selective cross-coupling of dichlorinated benzo-fused nitrogen-heterocycles having two chloro groups on the benzene ring. These dichlorinated heterocycles reacted with Grignard reagents in the presence of PdCl₂(PCy₃)₂ at the positions ortho to the nitrogen-based substituents with high selectivities. A mechanism in which interaction between Lewis acidic Mg and Cl of the ortho position facilitates C–Cl bond cleavage is proposed.

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Six new acylated anthocyanins (1—6) were isolated along with the three known congeners (7—9) from the fresh roots of red radishes (Raphanus sativus L.) cultivated by our group. Their chemical structures were elucidated by spectroscopic properties. Among the six new anthocyanins, the five constituents (1, 2, 4—6) were shown to contain the malonyl function at 6-OH in the glucopyranosyl residue linked to C-5 in the pelargonidin nucleus.

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Four new sesquiterpenoids, argutosines A—D (1—4), together with two known ones (5, 6), were isolated from the roots of Incarvillea arguta. Their chemical structures were elucidated on the basis of MS, NMR spectroscopic analysis. All the sesquiterpenoids were tested for inhibitory activities against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 macrophages. Argutosines A, B and C (1—3) showed potent inhibitory activities with IC₅₀ values of 2.05, 0.55, and 9.87 μM, respectively.

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Four new neo-clerodane diterpenoids, scutebarbatines W—Z (1—4), were isolated from the ethanol extract of Scutellaria barbata (Labiatae), and their structures were elucidated on the basis of extensive spectroscopic studies. In addition, the proposed structures of at least seven 13-spiro subtype neo-clerodanes: scutehenanine B (5), scutebarbatine G (6), 6-O-nicotinoylscutebarbatine G (7), barbatin A (8), 6,7-di-O-nicotinoylscutebarbatine G (9), 6-O-nicotinoyl-7-O-acetylscutebarbatine G (10), and scutebarbatine F (11), reported by Dai and co-workers from the same species, were incorrectly assigned and have been revised by reanalysis of the published NMR data.

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When 1,3-dimethyluric acid was treated with a nitric oxide donor, diethylamine NONOate, in an aerobic neutral solution and the reaction was analyzed by HPLC, 1,3-dimethyluric acid was consumed to yield a nitrosated derivative, which decomposed with a half-life of 17.9 min at pH 7.4 and 37 °C. When 1,3,7-trimethyluric acid was treated with diethylamine NONOate, no consumption of 1,3,7-trimethyluric acid was observed. However, in the reaction of N-acetylcysteine with diethylamine NONOate, the yield of N-acetyl-S-nitrosocysteine increased by the addition of 1,3,7-trimethyluric acid as well as 1,3-dimethyluric acid. For 1,3,7,9-tetramethyluric acid, no consumption in the reaction with diethylamine NONOate and no effect on the S-nitrosation were observed. These results suggest that 1,3-dimethyluric and 1,3,7-trimethyluric acids are both nitrosated by diethylamine NONOate on the nitrogen atom of their oxoimidazole ring, although the half-life of the nitrosated 1,3,7-trimethyluric acid is too short to detect by HPLC. Consequently, these two acids can act as vehicles of nitric oxide.

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Four new acylated acyclic sesquiterpene oligoglycosides (1—4) were isolated from the pericarps of Sapindus rarak DC. together with four known acyclic sesquiterpene oligoglycosides, mukuroziosides Ia (5), Ib (6), IIa (7), and IIb (8). Their structures were elucidated on the basis of chemical and physicochemical evidence. These newly isolated compounds (1—4) were found to show inhibitory effects on tumor necrosis factor-α-induced cytotoxicity in L929 cells at concentrations of 30—100 μM.

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