We discovered that the reactivity of some conjugated and electron-deficient hydrocarbons was quite different in the presence of transition metal catalysts. In this review we report our development and applications of the highly selective palladium and nickel-catalyzed cycloaddition reactions of unsaturated hydrocarbons such as conjugated enynes, electron-deficient allenes, and electron-deficient methylenecyclopropanes. Some homocoupling reactions as well as co-cyclization reactions were described. The efficient synthesis of 4—7 membered carbocycles was achieved.

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Lanthanide(III) complexes of the general formula [Ln(ACAB)₂(NO₃)₂(H₂O)₂]·NO₃·H₂O where Ln=La(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III) and Y(III), ACAB=3-acetylcoumarin-o-aminobenzoylhydrazone have been isolated and characterised based on elemental analyses, molar conductance, IR, ¹H- and ¹³C-NMR, UV, TG/DTA and EPR spectral studies. The ligand behaves in bidentate fashion coordinating through hydrazide >C=O and nitrogen of >C=N. A coordination number of ten is assigned to the complexes. Antibacterial and Antifungal studies indicate an enhancement of activity of the ligand on complexation.

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This paper describes the preparation of two layered device comprising of tenoxicam containing layer and a drug free membrane layer based on Geomatrix^® Technology. Our device based on bilaminated films which produced by a casting/solvent evaporation technique. The drug–hydroxypropyl methylcellulose (HPMC) layer was covered by drug free membrane layer composed of a mixture of different ratios of HPMC and ethyl cellulose (EC). The prepared devices were evaluated for thickness, weight, drug content uniformity, water absorption capacity and in-vitro drug release. The films were also evaluated for appearance, smoothness and transparency. The influence of drug free membrane layer composition and thickness on the drug release pattern was studied on 12 devices (D1 to D12). The results indicate that, the release of drug from HPMC matrixes without the drug free membrane layer was fast and follows diffusion controlled mechanism. The release of drug from the devices D1, D4, D9 and D12 follow the same mechanism, while the release of drug from other devices become linear with time (zero order) and extended for long time especially when thickness and the ratio of EC was increased in the drug free membrane layer. From this study it is concluded that, changing the geometry of drug layer by addition of drug free membrane layer and changing its composition and thickness plays an important role in determining whether the drug free membrane layer is rate-controlling or modulator membrane. Hence it can facilitate the development of different pharmaceutical products with different release pattern.

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We describe the synthesis of 2-[(4-hydroxyphenyl)thio]-7-isopropoxy-5,6-dimethoxy-4H-chromen-4-one 2 from 3,4,5-trimethoxyphenol 6 via the key intermediate, 3-iodo-7-isopropoxy-5,6-dimethoxy-4H-chromen-4-one 3. An important feature of this synthetic scheme involves selective alkylation, which can be achieved by two different routes. One route involves the selective isopropylation of a triacetate derivative 4 under basic conditions. The second route employs the selective demethylation of a trimethoxy derivative 5 under acidic conditions followed by isopropylation. The product of these alternative routes, compound 3, is then converted to a capillarisin sulfur analogue 2 in a one-pot reaction via the imidazolyl intermediate 22.

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TiO₂ has been widely used in pharmaceutical products, and it also has been used as a photocatalyst. In this study, the influence of photocatalytic activity on the stability of solid-state mequitazine, an H₁-blocker, was investigated. The photo-degradation of mequitazine with TiO₂ occurred under irradiation with both light sources. The degree of degradation of mequitazine with anatase was higher than that of rutile. The degradation was significantly enhanced with increasing relative humidity. The relationship between the apparent degradation rate constant and water vapor pressure could be clearly described by a simple power law. The major photo-degradation products of mequitazine, resulting from photocatalytic activity of TiO₂, were mequitazine-S-oxide and mequitazine-sulphone. A remarkable degradation of mequitadine occurred with addition of TiO₂, and its photocatalytic activity was controlled by water vapor pressure. The photo-degradation of mequitazine with TiO₂ is a different process from mequitazine without TiO₂, because mequitazine-S-oxide and mequitazine-sulphone are not formed with normal photo-degradation of mequitazine.

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The aim of this study was to investigate the influence of cosolvent polarity on the rheological flow properties of aqueous and hydroalcoholic gels obtained from the Carbopol^® Ultrez^TM 10 base and used for topical applications. Specifically, we have examined the effect of pH (range 4.0—7.0) on the consistency and flow properties of dispersed systems in water and mixtures—15 : 85% v/v of methanol : water, ethanol : water, n-propanol : water and n-butanol : water—at a constant polymer concentration of 0.3% w/w. The gels, which had decreasing polarity values in the jellifying medium, showed qualitatively similar flow behavior, characteristic of pseudoplastic systems, and all of the flow curves were adjusted to the Ostwald model. Sigmoidal dose response functions were calculated to describe the flow and consistency indexes as a function of pH. As a result, the influence of alcohol polarity on the polymer network has been assessed meaningfully using the empirical parameters obtained: maximum consistency index value (k_max), pH value required for 50% development of polymer network (pH₅₀), and asymptotic flow index value (n_min) for the fully structured gels.

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Olean-11,13(18)-dien-3β,30-diol dihemiphthalate (3), which was derived from glycyrrhetinic acid (GA), has been reported to produce a potent of anti-inflammatory effect in in vivo assays. Using 3 as a lead compound, we attempted to synthesize some modified compounds which varied in the following; i) the position of a carboxyl group in the phthalate moiety, ii) the number of carboxyls attached to the benzoyl group, iii) conversion of benzene ring to another ring system, iv) the linkage form between the benzene ring and oleanene skeleton at position 3 and/or 30. These were screened for their inhibitory activity against interleukin-1β (IL-1β)-induced prostaglandin E₂ (PGE₂) production in normal human dermal fibroblasts (NHDF). Although conversion of the ortho-carboxyl group of 3 into the meta-position or the para-position led to an increase in inhibitory activity, the elimination or increase of the carboxyl group resulted in loss of the inhibitory activity. Conversion of the ester bond to the amide bond at position 3 and/or 30 of 3 did not contribute to a significant increase in inhibitory activity. On the other hand, among the derivatives possessing an anthranilic acid moiety at position 30 of 3β-O-acetyl-olean-11,13(18)-dien-30-oic acid (20), 3β-hydroxy-30-nor-olean-11,13(18)-dien-20β-[N-(2-carboxyphenyl)]carboxamide (30) showed the most potent inhibitory activity (IC₅₀ 1.0 μM) in this series.

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Three new dihydrophenanthrenes, 4-methoxy-9,10-dihydrophenanthrene-1,2,7-triol (1), 1-(4-hydroxybenzyl)-4,7-dimethoxy-9,10-dihydrophenanthrene-2-ol (2), and 1,3,6-tri(4-hydroxybenzyl)-4-methoxydihydrophenanthrene-2,7-diol (3) together with seven known phenanthrene derivatives, six known flavonoids, a bibenzyl and three phenolic compounds were isolated from the whole plant of Bletilla formosana. Their structures were elucidated by spectroscopic, mainly 2D NMR spectrometry and chemical methods.

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In the course of our rsearch for new antifungal agents, two new meroterpenoids, penisimplicin A (1) and B (2), were isolated from Penicillium simplicissimum. The absolute structures of 1 and 2 were established by spectroscopic and chemical investigation. Penisimplicin A (1) and B (2) are rare examples of D-ring seco-meroterpenoids. Since compounds 1 and 2 showed no antifungal activities, the isolation of the compounds with antifungal activity will be attempted.

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Three new flavonoid derivatives, 6′′′-O-acetyl amurensin (1), 6′′′-O-acetyl phellamurin (3) and (2R)-phellodensin-F (5), together with thirty known compounds have been isolated from the leaves of Phellodendron japonicum MAXIM. Their structures were established by means of spectroscopic analysis, including extensive 2D NMR and Mass spectra. The known compounds were identified by comparison with published physical and spectral data. The isolated compounds were screened for their in vitro antioxidant activity through DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging assay. Compounds quercetin and phellodenin-A demonstrated significant radical scavenging activity.

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Three novel 22-β-O-spirostanol oligoglycosides, torvosides J (1), K (2) and L (3) have been isolated from the fruits of Solanum torvum SWARTZ and their chemical structures have been characterized based on the spectroscopic means. They are worth of note as rare 22-β-O-spirostanol glycosides.

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Phytochemicals investigation of the whole plant of Zygophyllum atriplicoides resulted in the isolation of two new triterpenoidal saponins together with a known compound. The structure of the new compounds atriplicosaponin A (1) and atriplicosaponin B (2) were established as 3-O-[α-D-glucopyranosyl-(1→2)-β-D-xylopyranosyl]hederagenin and 27α-hydroxyurs-12-ene-3-O-[β-D-glucopyranosyl(1→4)(2-O-sulpho)-β-D-quinovopyranoside] and known compound was identified as 3-O-[β-D-glucopyranosyl]-β-sitosterol. The structure elucidations of the compounds were based primarily on 1D and 2D-NMR analysis, including COSY, HMBC and HMQC correlations.

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The synthesis of an asymmetric glycocluster 1 has been achieved using two glycocluster units 12 and 13, prepared by coupling the cluster chain unit 4 with each ω-amino acid (β-alanine and 6-aminocapronic acid) trichloroethyl ester, and peptidic C-terminal block glycocluster 16, prepared by coupling the bifunctional linker 14 with sugar unit 9. This method facilitated the synthesis of the cluster optionally modulated the distance between the side-chain branched points by using various ω-amino acids. We also synthesized glycodendron 2 using the same intermediate.

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Continuing our ongoing studies on cytotoxic substances, a series of regioisomeric disubstituted aminoanthraquinone (DAAQ) derivatives have been synthesized as cytotoxic activity based on a proposed bioactive amino conformation. To assess the biological activity of amino-substitution in the side-chains of anthraquinone located at positions 1 and 8 of the anthraquinone ring system. The aim of the study was to determine if members of the anthraquinone family could be used as adjuncts to increase the growth inhibiting effect of anticancer agents in rat glioma C6 cells, human hepatoma G2 cells and 2.2.15 cells. In vitro cytotoxicity data is reported for the compounds and some indications of structure–activity relationships have been discerned. A number of compounds were found to have good cytotoxicity against proliferation in these three cell lines. This has led to the discovery some of the DAAQ as a conformationally constrained structure possessing anticancer properties that displays cytotoxicity for these above cell lines and is being investigated further.

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The process of vesicle destruction by zwitterionic detergent, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), was examined to clarify the vesicle-micelle transition mechanism. The physicochemical properties including turbidity, apparent particle size, Cl⁻ permeability, electron spin resonance (ESR) spectroscopic parameters, and freeze-fracture electron microscopy were investigated. The concentration of CHAPS was analyzed using HPLC to determine the partition coefficient during the solubilization process. The data obtained revealed that maximum turbidity and apparent particle size were found at the effective ratio (R_e) of 0.21 and 0.49, respectively. With a further increase in CHAPS concentration, turbidity and particle size abruptly decreased, suggesting the formation of mixed micelles. The partition coefficient changed throughout the solubilization process. In the presence of low concentrations of CHAPS, CHAPS partitioned into vesicles without destruction of membrane bilayers. When the R_e<0.04, the partition coefficient was independent of the detergent concentration with value of 24 M⁻¹. At R_e greater than 0.05, the membrane barrier abruptly decreased. At 0.04≤R_e<0.21, the gradual increase in the partition coefficient accounted for the occurrence of larger vesicles. In range of 0.21≤R_e<0.52, the abrupt increase in the partition behavior was possibly attributed to the structural change of mixed vesicles to mixed micelles. Furthermore, the ESR results showed that the incorporation of CHAPS into vesicles led to an increase in membrane fluidity near the polar head, and a decrease near the end of the acyl chain. ESR spectra of 5-doxylstearic acid in CHAPS-containing micelles were anisotropic, indicating that the steroidal structure of CHAPS was responsible for the micelles possessing an orderly arrangement of hydrocarbon chains.

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The structures of 6 new oleanene glycosides (1—6) isolated from the leaves of Acanthopanax japonicus FRANCH et. SAVART (Araliaceae) were elucidated by mass, 1D, and 2D NMR spectroscopy. The structures of 1—6 were established as 28-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl] ester of 3β,23-dihydroxy-olean-12-en-28,29-dioic acid, 3β,30-dihydroxy-olean-12-en-23,28-dioic acid, 3β,29-dihydroxy-olean-12-en-23,28-dioic acid (=dianic aicd), 3β-dihydroxy-olean-12-en-23,28-dioic acid (=gypsogenic acid), 3β,29-dihydroxy-23-oxo-olean-12-en-28-oic acid, and 3β-hydroxy-23-oxo-olean-12-en-28,29-dioic acid, designated acanjaposide D (1), E (2), F (3), G (4), H (5), and I (6), respectively.

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1,2-Dihydropyrazin-2-one derivatives, which have two aminoalkyl groups at the positions 3 and 6, were found to be efficient tools for the construction of potent, selective and long-acting opioid mimetics. During the course of preparation, we found that the catalytic hydrogenation of 3,6-bis(benzyloxycarbonylaminomethyl)-5-methyl-1,2-dihydropyrazin-2-one to remove the benzyloxycarbonyl groups resulted in a side reaction. By MS and NMR studies and by preparation of additional 1,2-dihydropyrazin-2-one derivatives, the structure of the by-product was identified as 3-aminomethyl-5,6-dimethyl-1,2-dihydropyrazin-2-one. Preparation of additional compounds substituted with deuterium provided us with sufficient information to confirm the structure of the product and to support a cyclization mechanism in its formation.

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Four new plastoquinones were isolated from the methanolic extract of the brown alga, Sargassum micracanthum. Their structures were elucidated based on spectroscopic analysis and chemical conversions from 2-geranylgeranyl-6-methyl-1,4-benzohydroquinone. These plastoquinones exhibited significant antioxidant activities such as an inhibitory effect on lipid peroxidation and a radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH). Some of the new plastoquiones showed cytotoxic activity against cancer cell line.

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From the 95% EtOH extract of the cortexes of Polygala tenuifolia, four new phenones and three known xanthones were isolated. The structures of the four new phenones were identified as 4-O-[α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl]-2-hydroxyl-6-methoxybenzophenone (tenuiphenone A, 1), 3,5-di-C-β-glucopyranosyl-2,4,6,3′-tetrahydroxybenzophenone (tenuiphenone B, 2), 2′,4′,6′-trihydroxyphenyl-(24Z)-triacontene-1-one (tenuiphenone C, 3), 2′,4′,6′-trihydroxyphenyl-(26Z)-dotriacontene-1-one (tenuiphenone D, 4) respectively, on the basis of spectroscopic analyses. The isolation of 1 and 2 supplied an evidence for the hypothesis that xanthone was biosynthesized from benzophenone in the plants.

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Many researchers have stated that eugenol might inhibit lipid peroxidation at the stage of initiation, propagation, or both, and many attempts have been made to elucidate the mechanism of its antioxidant activity. Nevertheless, details of its mechanism are still obscure. This study was carried out to investigate the trapping effect of eugenol on hydroxyl radical generated from L-3,4-dihydroxyphenylalanine (DOPA) in MiliQ water and the generation mechanism of the hydroxyl radical by this system which uses no metallic factor. This was studied by adding L-DOPA and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) to phosphate buffered saline (PBS) or MiliQ water, and the generation of hydroxyl radical was detected on an ESR spectrum. By this method, the effect of antioxidants was detected as a modification of ESR spectra. We found that the eugenol trapped hydroxyl radicals directly, because it had no iron chelating action, did not trap L-DOPA semiquinone radical and inhibited hydroxyl radicals with or without iron ion.

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We synthesized some 4,4′- and 2,2′-dihydroxytriphenylmethane derivatives 3a—e and 4a—c by condensation of phenol 1 and aromatic aldehyde 2 in moderate to good yields (30—83%). Most of them showed significant antiviral activity against herpes simplex virus type 1 (anti-HSV-1 activity) in a plaque reduction assay. The most potent antiviral activity (EC₅₀=0.79 μg/ml) was observed in the 4,4′-dihydroxytriphenylmethane derivative 3b. This compound 3b showed lower cytotoxicity (CC₅₀=30.2 μg/ml), compared to that of the prototype 3a.

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Two new bisabolane-type sesquiterpenes, lippidulcine A (3) and epilippidulcine A (4), have been isolated from the aerial parts of Lippia dulcis TREV. along with five known flavonoids, cirsimaritin (5), salvigenin (6), eupatorin (7), 5-hydroxy-6,7,3′,4′-tetramethoxyflavone (8) and 5,3′-dihydroxy-6,7,4′,5′-tetramethoxyflavone (9), three known phenylethanoid glycosides, decaffeoylverbascoside (10), acteoside (11) and isoacteoside (12), and two known iridoid glucosides, 8-epiloganin (13) and lamiide (14). Their chemical structures have been determined on the basis of spectroscopic data. Among them, 5, 7, and 9 exhibited almost the same activity as that of α-tocopherol, and 10—12 were identified as stronger antioxidants than α-tocopherol using the ferric thiocyanate method.

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A novel monoterpene alkaloid, named incarvillateine E, possessing three moles of incarvilline moieties, has been obtained from the aerial parts of Incarvillea sinensis LAM. (Bignoniaceae). On the basis of spectroscopic evidence, the structure of incarvillateine E has been characterized.

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Bismurrangatin and murramarin A, two new coumarins, were isolated from the vegetative branches of Murraya exotica. Murramarin A is a rare type of bicoumarin that connects two coumarin moieties by orthoester structure. The structures were elucidated based on spectroscopic methods, especially by 2D-NMR experiments.

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A series of N-substituted 2-(2-chloroacetamido)-3-(furan-2-yl)propanamides (16—18) was prepared through the reaction of chloroacetyl chloride with N-substituted 2-amino-3-(furan-2-yl)propanamides (15), which were obtained via condensation of 2-(tert-butoxycarbonylamido)-3-(furan-2-yl)propanoic acid (Boc-furylalanine) (8) with amines (9, 11, 13), followed by hydrolysis of the resultant N-substituted Boc-furylalanine acid amides (10, 12, 14) in the presence of HCl/dioxane. The biological activity of the prepared 16, 17 and 18 as root growth inhibitors was examined by germination assay using rape seed. At the concentration of 5.0×10⁻⁵ M, the most active compound, 2-(2-chloroacetamido)-N-(2,6-diethylphenyl)-3-(furan-2-yl)propanamide (16n), showed potent root growth-inhibitory activity of 76% towards rape seedlings.

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The total assignment of the ¹H- and ¹³C-NMR spectra for TZT-1027 was carried out using various NMR methods (1D, 2D NMR). It was found that TZT-1027 exists in two different conformations resulting from the cis–trans isomerization of the amide bond at N-11 and C-12 in DMSO-d₆. The ¹H- and ¹³C-NMR spectra of compound 1 and 2 comprised of the partial structure of TZT-1027 were also assigned to be TZT-1027. These assignments showed that compound 1 is in good agreement with TZT-1027 with regard to formation of the conformers.

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A new polyacetylene, gymnasterkoreayne G (1) and seven known (2—8) constituents were isolated from the leaves of Gymnaster koraiensis. Base on extensive 1D and 2D NMR spectroscopic data, the structure of the new compound was identified as erythro-8(S)-9(Z),16-heptadecadiene-4,6-diyne-2,3,8-triol. Isolated compounds were evaluated for their ability to inhibit NFAT transcription factor. While other components did not show activity, most of polyacetylene components markedly inhibit NFAT transcription factor. Of these compounds, gymnasterkoreayne B (3) was the most potent (IC₅₀ 1.44±0.59 μM). In term of the isomers, compound 1 (IC₅₀ 43.9±2.24 μM) with an erythro-configuration showed less inhibition than 2 (IC₅₀ 7.24±0.42 μM) with a threo-configuration.

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The racemic structure of (1RS,3RS)-1,2,3,4-tetrahydro-6,7-dihydroxy-1-methyl-3-isoquinolinecarboxylic acid [(1RS,3RS)-1] was examined based on the melting point, solubility, and IR spectrum, with the aim of optical resolution by preferential crystallization. (1RS,3RS)-1 was indicated from these results to exist as a conglomerate. The successive optical resolution by preferential crystallization of (1RS,3RS)-1 yielded (1S,3S)- and (1R,3R)-1 with optical purities of 85—95% at 66—81% degrees of resolution, which were fully purified by recrystallization.

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Phytochemical investigation of Ginkgo biloba (Ginkgoaceae) has resulted in the isolation of two new biflavone glucosides, ginkgetin 7″-O-β-D-glucopyranoside (1) and isoginkgetin 7-O-β-D-glucopyranoside (2). The structures were determined on the basis of chemical and spectroscopic evidences.

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Two new aromatic compounds, erinacerins A (1) and B (2), were isolated from the fruiting bodies of Hericium erinaceum (BULL.: FR.) PERS. (Hericiaceae) together with a known compound, hericenone A (3). The structures of the new compounds were elucidated on the basis of their spectral data. It was found that 1 occurred as a racemate.

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Caragana tibetica KOM. (Fabaceae) is a medicinal plant that has been traditionally used in western part of China. In the course of our screening study on antioxidant activity of medicinal plants, the 70% acetone extract of the stems of C. tibetica was found to have a potent superoxide anion scavenging activity. Tibeticanol (1), a new piceatannol dimer possessing antioxidant activity, was isolated along with eleven known aromatic compounds. Their structures were elucidated on the basis of NMR and MS data. Enzyme oxidation of monomeric stilbene, piceatannol (3), with horseradish peroxidase and hydrogen peroxide yielded cassigarol E (5) and G (6) as major products. Most of the isolated compounds exhibited superoxide anion scavenging activity.

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Three new carotenoids with a 3,4-dihydroxy-β-end group were isolated from the oyster Crassostrea gigas. These structures were determined to be 3,4,3′,8′-tetrahydroxy-β,κ-caroten-6′-one (1), 3,4-dihydroxy-3′,6′-epoxy-1′,2′,5′,6′7′,8′-hexahydro-6′-methyl-16′-nor-β,-carotene-1′,8′-dione (2), and 3,6-epoxy-5,3′,4′-trihydroxy-12′,13′,20′-trinor-β,β-caroten-19,11-olide (3) based on chemical and spectral data.

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