Showing papers in "Chemical & Pharmaceutical Bulletin in 2005"

Determination of in vitro antioxidant and radical scavenging activities of propofol.

Abstract: Propofol (2,6-diisopropylphenol) is a hypnotic intravenous agent with in vivo antioxidant properties. This study was undertaken to examine the in vitro antioxidant activity of propofol using different antioxidant tests including by 1,1-diphenyl-2-picryl-hydrazil (DPPH.) radical scavenging, metal chelating, hydrogen peroxide scavenging, superoxide anion radical scavenging, reducing power and total antioxidant activities. At the concentrations of 25, 50, and 75 microg/ml, propofol exhibited 97.7, 98.6 and 100% inhibition on peroxidation of linoleic acid emulsion, respectively. On the other hand, at the 75 microg/ml concentration of standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and alpha-tocopherol exhibited 88.7, 94.5, and 70.4% inhibition on peroxidation of linoleic acid emulsion, respectively. In addition, at same concentrations, propofol was shown that it had effective reducing power, DPPH. free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and metal chelating activities. These various antioxidant activities were compared to standard antioxidants such as BHA, BHT and alpha-tocopherol. These results indicate that propofol prevents lipid peroxidation and radicalic chain reactions. At the same time, propofol revealed more effective antioxidant capacity than BHA, BHT and alpha-tocopherol.

Piperine from the Fruits of Piper longum with Inhibitory Effect on Monoamine Oxidase and Antidepressant-Like Activity

Abstract: A bioassay-guided isolation of the ethanol extract from the fruits of Piper longum yielded a known piperidine alkaloid, piperine, as a monoamine oxidase (MAO) inhibitor. Piperine showed an inhibitory effect against MAO-A (IC50 value: 20.9 μM) and MAO-B (IC50 value: 7.0 μM). Kinetic analyses by a Lineweaver–Burk plot clearly indicated that piperine competitively inhibited MAO-A and MAO-B with Ki values of 19.0±0.9 μM and 3.19±0.5 μM, respectively. The inhibition by piperine was found to be reversible by dialysis of the incubation mixture. In addition, the immobility times in the tail suspension test were significantly reduced by piperine, similar to that of the reference antidepressant fluoxetine, without accompanying changes in ambulation when assessed in an open-field. These results suggest that piperine possesses potent antidepressant-like properties that are mediated in part through the inhibition of MAO activity, and therefore represent a promising pharmacotherapeutic candidate as an antidepressant agent.

Multi-component HPLC Fingerprinting of Radix Salviae Miltiorrhizae and Its LC-MS-MS Identification

Abstract: The multi-component fingerprinting method of Radix Salviae Miltiorrhizae (Root of Salvia miltiorrhiza BGE.), an important and popular medicinal herb in traditional Chinese medicine, was studied using reverse-phase HPLC and LC-MS-MS. Extract containing both the water-soluble phenolic compounds and nonpolar diterpenoid compounds known to be the herb's main bioactive components was prepared by a two-step extractive procedure. An HPLC fingerprinting method which can simultaneously separate these two types of compounds was established with gradient elution mode and photodiode array detection at 280 nm. Eighteen peaks in this HPLC fingerprint were structurally identified by employing LC-MS-MS techniques. The electrospray ionization (ESI) MS-MS spectra of most salvianolic acids displayed a characteristic behavior of loss of danshensu and caffeic acid moieties, while those of tanshinones showed a particular behavior of loss of H2O which is quite different from the fragmentation pattern in electron ionization mass spectrometry (EI-MS). The HPLC fingerprints of 7 batches of crude drugs showed similar separation pattern and provided much chemical information of the pharmacologically-active compounds in the crude drugs, which is useful for the authentication and quality evaluation of this medicinal herb.

Calculation of the viscosity of binary liquids at various temperatures using Jouyban-Acree model.

Abstract: Applicability of the Jouyban-Acree model for calculating absolute viscosity of binary liquid mixtures with respect to temperature and mixture composition is proposed. The correlation ability of the model is evaluated by employing viscosity data of 143 various aqueous and non-aqueous liquid mixtures at various temperatures collected from the literature. The results show that the model is able to correlate the data with an overall percentage deviation (PD) of 1.9+/-2.5%. In order to test the prediction capability of the model, three experimental viscosities from the highest and lowest temperatures along with the viscosities of neat liquids at all temperatures have been employed to train the model, then the viscosity values at other mixture compositions and temperatures were predicted and the overall PD obtained is 2.6+/-4.0%.

Metabolic fingerprinting of Ephedra species using 1H-NMR spectroscopy and principal component analysis.

Abstract: The metabolomic analysis of Ephedra species was performed using 1H-NMR spectroscopy and multivariate data analysis. A broad range of metabolites could be detected by 1H-NMR spectroscopy without any chromatographic separation. The principal component analysis used to reduce the huge data set obtained from the 1H-NMR spectra of the plant extracts clearly discriminated three different Ephedra species. The major differences in Ephedra sinica, Ephedra intermedia and Ephedra distachya var. distachya were found to be due to benzoic acid analogues in the aqueous fraction and ephedrine-type alkaloids in the organic fraction. Based on this metabolomic recognition, one of nine commercial Ephedra materials evaluated was shown to be a mixture of Ephedra species. This method will be a useful tool for chemotaxonomic analysis and authentification of Ephedra species including quality control of plant materials.

Aromatic constituents from the heartwood of Santalum album L.

Abstract: A phytochemical investigation of the polar constituents in the heartwood of Indian Santalum album L. resulted in the isolation of three new neolignans (1-3) and a new aromatic ester (4), along with 14 known components. The structures of the new compounds (1-4) were established using spectroscopic methods.

Antitumor activity of Pulsatilla koreana saponins and their structure-activity relationship.

Abstract: Seventeen saponins isolated from the root of Pulsatilla koreana were examined for their in vitro cytotoxic activity against the human solid cancer cell lines, A-549, SK-OV-3, SK-MEL-2, and HCT15, using the SRB assay method, and their in vivo antitumor activity using BDF1 mice bearing Lewis lung carcinoma (LLC). The saponins 5-17, with a free acidic functional group at C-28 of aglycon, exhibited moderate to considerable cytotoxic activity, however, the saponins 1-4, esterified with a trisaccharide at C-28 of aglycon, did not exhibit cytotoxic activity (ED50; >300 microM). Among them, oleanolic acid 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranoside (10) exhibited the most potent cytotoxic activity (ED50; 2.56, 2.31, 1.57, 8.36 microM, respectively). In vivo test, hederagenin 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranoside (6, Inhibition Ratio, IR; 66.9%) exhibited more potent antitumor activity than taxol (IR; 35.8%) and doxorubicin (IR; 62.1%). Also, hedragenin 3-O-beta-D-glucopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside (17, IR; 50.3%) exhibited potent antitumor activity. These two saponins were identically comprised of a hederagenin aglycon moiety and a sugar sequence O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside at C-3 of the hederagenin, suggesting that the two elements are essential factors for the antitumor activity.

Lipid carrier systems for targeted drug and gene delivery.

Abstract: For effective chemotherapy, it is necessary to deliver therapeutic agents selectively to their target sites, since most drugs are associated with both beneficial effects and side effects. The use of lipid dispersion carrier systems, such as lipid emulsions and liposomes, as carriers of lipophilic drugs has attracted particular interest. A drug delivery system can be defined as a methodology for manipulating drug distribution in the body. Since drug distribution depends on the carrier, administration route, particle size of the carrier, lipid composition of the carrier, electric charge of the carrier and ligand density of the targeting carrier, these factors must be optimized. Recently, the lipid carrier system has also been applied to gene delivery systems for gene therapy. However, in both drug and gene medicine cases, a lack of cell-selectivity limits the wide application of this kind of drug and/or gene therapy. Therefore, lipid carrier systems for targeted drug and gene delivery must be developed for the rational therapy. In this review, we shall focus on the progress of research into lipid carrier systems for drug and gene delivery following systemic or local injection.

Quality Assessment of Radix Salviae Miltiorrhizae

Abstract: This paper describes an improved quality assessment method for Radix Salviae Miltiorrhizae (Root of Salvia miltiorrhiza BGE.) which was established using chromatographic fingerprinting and quantification of multiple marker compounds in the crude drug. High-performance thin-layer chromatography (HPTLC) fingerprinting of water-soluble phenolics and nonpolar tanshinones was performed separately and the authentication of Radix Salviae Miltiorrhizae was achieved by comparing the fingerprints of the samples with those of the reference crude drug and by comparing the Rf values of the bands in TLC fingerprints with those of reference compounds. HPLC fingerprints were obtained by simultaneous separation of phenolics and diterpenoids in Radix Salviae Miltiorrhizae. The HPLC fingerprints of seven batches of samples from different regions of China showed similar chromatographic patterns, and seven peaks were selected as characteristic peaks. The relative retention time of these characteristic peaks in the HPLC fingerprints was established as an important parameter for the identification of this herbal medicine. The pharmacologically active marker compounds salvianolic acid B, rosmarinic acid, and tanshinone IIA in herbal medicine were quantitatively determined using reverse-phase HPLC techniques. The HPLC quantitation methods of the three marker compounds were validated and the measurement uncertainty, which is important for setting the proposed content limit of the marker compounds in herbal medicine, were further evaluated.

Highly Efficient Production of Nootkatone, the Grapefruit Aroma from Valencene, by Biotransformation

Abstract: Nootkatone (2), the most important and expensive aromatic of grapefruit, decreases the somatic fat ratio, and thus its demand is increasing in the cosmetic and fiber sectors. A sesquiterpene hydrocarbon, (+)-valencene (1), which is cheaply obtained from Valencia orange, was biotransformed by the green algae Chlorella species and fungi such as Mucor species, Botryosphaeria dothidea, and Botryodiplodia theobromae to afford nootkatone (2) in high yield.

New diarylheptanoids from Alnus japonica and their antioxidative activity.

Abstract: In the course of research on the bioactive constituents of woody plants in the Cyugoku area of Japan, a methanol extract of the leaves of Alnus japonica were found to have strong antioxidative activity. Ethyl acetate soluble and n-buthanol soluble fractions of the methanol extract had a potent antioxidative effect. Both fractions were purified by silica gel column chromatography and HPLC using an ODS column to give four new diarylheptanoids along with known diarylheptanoids and flavonoids. These new compounds were elucidated to be 7-(3,4-dihydroxyphenyl)-5-hydroxy-1-(4-hydroxyphenyl)-3-heptanone-5-O-beta-D-xylopyranoside (1), 1-(3,4-dihydroxyphenyl)-5-hydroxy-7-(4-hydroxyphenyl)-3-heptanone-5-O-beta-D-xylopyranoside (2), 1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxy-3-heptanone-5-O-[2-(2-methylbutenoyl)]-beta-D-xylopyranoside (3) and 1,7-bis-(3,4-dihydroxyphenyl)-5-methoxy-3-heptanone (4) using spectral methods and especially 1H-, 13C-NMR and 2D-NMR measurements. The isolated compounds including their main constituent, oregonin (5), were tested for antioxidative activity. Some of these compounds having two catechol structures showed potent antioxidative activity. Compounds having one catechol structure showed moderate antioxidative activity, but a peracetate of 5 having no catechol structure exhibited no antioxidative activity. Thus the catechol structure of the diarylheptanoids is indispensable for antioxidative activity.

New anthraquinone and iridoid from the fruits of Morinda citrifolia.

Abstract: From the fruits of Morinda citrifolia L., one new anthraquinone, 5,15-O-dimethylmorindol, together with five known anthraquinones and one new iridoid, morindacin, together with two known iridoids, were isolated. Their structures were elucidated by analysis of spectroscopic data.

Improvement of fluorescence characteristics of coumarins: syntheses and fluorescence properties of 6-methoxycoumarin and benzocoumarin derivatives as novel fluorophores emitting in the longer wavelength region and their application to analytical reagents.

Abstract: To improve the fluorescence characteristics, especially emission wavelength, of coumarins, various 3-substituted-6-methoxycoumarin derivatives were synthesized, and then benzocoumarin derivatives were also synthesized in expectation of the shift to the longer wavelength region by the extension of the conjugated system. Their fluorescence properties were investigated spectrophotometrically in acetonitrile and evaluated from the viewpoint of the intramolecular charge transfer (ICT) between push- and pull-substituents in the ground and the excited states. Among them, benzocoumarin derivatives especially fluoresced in the longer wavelength around 540 nm with remarkably large Stokes shifts beyond 10000 cm - 1 . Using such fluorophores, some novel fluorescence derivatization reagents for carboxylic acids, alcohols, phenols, and amines were preliminarily prepared as an example, and their derivatized products were also found to fluoresce in the longer wavelength region with large Stokes shifts.

Stereoselective oxidation at C-4 of flavans by the endophytic fungus Diaporthe sp. isolated from a tea plant.

Abstract: The microbial transformation of five flavans (1—5) by endophytic fungi isolated from the tea plant Camellia sinensis was investigated. It was found that the endophytic filamentous fungus Diaporthe sp. oxidized stereoselectively at C-4 position of (+)-catechin (1) and (−)-epicatechin (2) to give the correspondent 3,4-cis-dihydroxyflavan derivatives (6, 10), respectively. (−)-Epicatechin 3-O-gallate (3) and (−)-epigallocatechin 3-O-gallate (4) were also oxidized by the fungus into 3,4-dihydroxyflavan derivatives (10, 12) via (−)-epicatechin (2) and (−)-epigallocatechin (11), respectively. Meanwhile, (−)-gallocatechin 3-O-gallate (5), (−)-catechin (ent-1) and (+)-epicatechin (ent-2), which possess a 2S-phenyl substitution, resisted the biotransformation.

Antimutagenic constituents from the thorns of Gleditsia sinensis.

Abstract: Antimutagenic activity-guided fractionation of an extract prepared from the thorns of Gleditsia sinensis LAM. led to the isolation of one triterpenoid and four steroids, which were identified as D:C-friedours-7-en-3-one (1), stigmast-4-ene-3,6-dione (2), stigmastane-3,6-dione (3), stigmasterol (4), and beta-sitosterol (5). Triterpenoid 1 was found for the first time in a natural source and the steroids 2-5 were first isolated from this plant. Stigmasterol was the most active antimutagen, showing 51.2% and 64.2% reduction of the induction factor against the mutagens MNNG and NQO, respectively, in the SOS chromotest. Some NMR data of the steroids 2 and 3 obtained have to be revised.

Antioxidative Phenols and Phenolic Glycosides from Curculigo orchioides

Abstract: A new orcinol glucoside, orcinol-1-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (3), was isolated from the rhizomes of Curculigo orchioides GAERTN., together with seven known compounds: orcinol glucoside (1), orcinol-1-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (2), curculigoside (4), curculigoside B (5), curculigoside C (6), 2,6-dimethoxyl benzoic acid (7), and syringic acid (8). The structures of these compounds were elucidated using spectroscopic methods. The antioxidant activities of these isolated compounds were evaluated by colorimetric methods based on their scavenging effects on hydroxyl radicals and superoxide anion radicals, respectively. All the compounds showed potent antioxidative activities and the structure-activity relationship is discussed.

Synthesis of optically active vomifoliol and roseoside stereoisomers.

Abstract: A synthesis of optically active vomifoliol stereoisomers 1-4 and their glucosides, roseoside stereoisomers 5-8, was accomplished via alpha-acetylenic alcohol 11a or 11b effectively prepared by an asymmetric transfer hydrogenation of alpha,beta-acetylenic ketone 10. Simultaneous separation of these stereoisomers by HPLC was also performed.

Studies on the Constituents of Juglans Species. I. Structural Determination of (4S)- and (4R)-4-Hydroxy-α-tetralone Derivatives from the Fruit of Juglans mandshurica M AXIM. var. sieboldiana M AKINO

Abstract: Four enantiomerically pure new α-tetralones, (4S)- and (4R)-5-hydroxy-4-methoxy-α-tetralones and (4S)- and (4R)-5,8-dihydroxy-4-methoxy-α-tetralones were isolated, together with five known ones, (4S)- and (4R)-4,8-dihydroxy-α-tetralones, (4S)-4,8-dihydroxy-5-methoxy-α-tetralone and (4S)- and (4R)-4-hydroxy-α-tetralones, from the fruit of Juglans mandshurica MAXIM. var. sieboldiana MAKINO. Their structures were established on the basis of spectral analysis. To the best of our knowledge, this is the first isolation of the (4R)-4-hydroxy-α-tetralone derivative from Juglans species.

Bioactive Saponins and Glycosides. XXIII. Triterpene Saponins with Gastroprotective Effect from the Seeds of Camellia sinensis—Theasaponins E3, E4, E5, E6, and E7—

Abstract: The saponin fraction from the seeds of the tea plant [Camellia sinensis (L.) O. KUNTZE (Theaceae)] was found to exhibit potent protective effects on ethanol- and indomethacin-induced gastric mucosal lesions in rats. Five new triterpene saponins, theasaponins E3 (1), E4 (2), E5 (3), E6 (4), and E7 (5), were isolated together with 11 known saponins from the saponin fraction. The chemical structures of 1-5 were elucidated on the basis of chemical and physicochemical evidence. Among the isolated saponins, theasaponins E1 (6), E2 (7), and E5 (3) and assamsaponin C (10) showed an inhibitory effect on ethanol-induced gastric mucosal lesions at a dose of 5.0 mg/kg, p.o. and their activities were stronger than that of omeplazole. With regard to the structure-activity relationships of theasaponins, the following structural requirements for a protective effect on ethanol-induced gastric lesions were suggested; 1) the 21- and/or 22-acyl groups are essential for the activity, 2) acetylation of the 16-hydroxyl group reduce the activity.

Cytotoxic allyl retrochalcone from the roots of Glycyrrhiza inflata.

Abstract: Two known retrochalcones, licochalcone A (1) and licochalcone C (2), and one new retrochalcone, licochalcone E (4) were isolated by cytotoxicity-guided fractionation from the roots of Glycyrrhiza inflata along with an ordinary chalcone, isoliquiritigenin (3). The structure of the new retrochalcone was elucidated through a spectroscopic analysis.

Synthesis and anti-inflammatory activity of resveratrol analogs.

Abstract: Seventeen novel resveratrol derivatives were synthesized. Their anti-inflammatory activities were tested on xylene-induced mouse ear edema. The pharmacological results showed that some compounds have potent anti-inflammatory activities.

Xanthine Oxidase Inhibitors from the Heartwood of Vietnamese Caesalpinia sappan

Abstract: From the MeOH extract of Vietnamese Caesalpinia sappan, a novel biogenetically exclusive benzindenopyran, with a new carbon framework, neoprotosappanin (1), and a new compound, protosappanin A dimethyl acetal (3), were isolated together with protosappanin E-2 (2), neosappanone A (4), and 13 previously reported phenolic compounds (5-17). Their structures were elucidated on the basis of spectroscopic data. Compounds 1-4, 7, 13, and 15-17 showed significant xanthine oxidase inhibitory activity in a concentration-dependent manner, and sappanchalcone (17) showed the most potent activity with an IC50 value of 3.9 microM, comparable to that of positive control allopurinol (IC50, 2.5 microM). The kinetic study of these inhibitors indicated that they are competitive inhibitors, the same as allopurinol, except for 1 and 16 which are noncompetitive inhibitors.

Bioactive Constituents from Chinese Natural Medicines. XV. : Inhibitory Effect on Aldose Reductase and Structures of Saussureosides A and B from Saussurea medusa

Abstract: The 80% aqueous acetone extract from the whole plant of Saussurea medusa MAXIM. was found to inhibit rat lens aldose reductase (IC50=1.4 microg/ml). From this extract, flavonoids, lignans, and quinic acid derivatives were isolated together with two new ionone glycosides, saussureosides A and B. Their absolute stereostructures were elucidated on the basis of chemical and physicochemical evidence including the application of modified Mosher's method. In addition, some isolates were found to show an inhibitory effect on aldose reductase.

Preparation and Evaluation of Proliposomes Containing Clotrimazole

Abstract: Clotrimazole (CT)-containing proliposomes were prepared by penetrating an ethanol solution of CT and Egg phosphatidylcholine (PC) into microporous sorbitol particles, followed by vacuum evaporation of the solvent. As a result, CT proliposomes with free-flowing flowability were obtained. On contact with water, the proliposomes were rapidly converted into a liposomal dispersion, in which a certain amount of CT was entrapped by the liposomes. The result in scanning electronic micrograph confirmed the formation of liposomes structures from proliposomes, and the particles revealed round or ellipse. The ratio of drug to total lipid, ratio of PC to cholesterol and ratio of lipid to sorbitol affected the entrapment efficiency (EE%). The EE% of optimized formulation (CT 10 mg, 0.1 g total lipid, PC/CH ratio is 60 : 40 and 1 g sorbitol) in this investigation was 96.2±1.5%. The proliposomes system can provide sustaining release in simulated vaginal fluid at 37±1 °C for 24 h. In-vivo performance of blank proliposomes, a physical mixture of sorbitol and drug, clotrimazole proliposomes and commercial ointment formulation were evaluated using antifungal activity test. At 7 d post-dose, the c.f.u. of C. albicans decreased in proliposomes-treated groups than ointment and the physical mixture (t-Student, p<0.05). The results indicated that CT-containing vaginal proliposomes prolonged drug release and may increase amount of drug retention into the mucosa to result in more antifungal efficacy. In addition, CT-proliposomes did not affect the morphology of vaginal tissues. Therefore, the dosage form might be further developed for safe, convenient, and effective treatment of vaginal candidasis with reduced dosing interval.

Cyclooxygenase-2 inhibitory phenylbutenoids from the rhizomes of Zingiber cassumunar.

Abstract: Phenylbutenoids isolated previously from the CHCl3 extracts of the rhizomes of Zingiber cassumunar, were evaluated for their cyclooxygenase-2 (COX-2) inhibitory activity along with a new isolate, from the n-BuOH extracts of this plant. The COX-2 inhibitory assay was performed by measuring prostaglandin E2 production in lipopolysaccharide-stimulated mouse macrophage RAW 264.7 cells. Two phenylbutenoid dimers, and, exhibited considerable activity with IC50 values of 2.71 and 3.64 microM. Two phenylbutenoid monomers, and, showed moderate activity (IC50 14.97, 20.68 microM, respectively). The other three phenylbutenoids, were found to be inactive. Compound was elucidated as a new phenylbutenoid glycoside, namely, (E)-4-(3,4-dimethoxyphenyl)but-3-en-1-O-beta-D-glucopyranoside by spectral analysis including various 1D- and 2D-NMR experiments.

Newbouldiaquinone and newbouldiamide: a new naphthoquinone-anthraquinone coupled pigment and a new ceramide from Newbouldia laevis.

Abstract: Newbouldiaquinone (1), a new naphthoquinone–anthraquinone coupled pigment and a new ceramide named newbouldiamide (2), have been isolated from Newbouldia laevis, besides the known compounds lapachol (3), canthic acid, oleanolic acid, 2-methyl-9,10-anthracenedione, 2-acetylfuro-1,4-naphthoquinone, 2,3-dimethoxy-1,4-benzoquinone, 2-(4-hydroxyphenyl)ethyl triacontanoate, β-sitosterol and β-sitosterol glucopyranoside. The structure elucidations of the isolated new compounds were performed on the basis of spectroscopic and chemical evidence. Preliminary studies showed that 1 is moderately antibacterial against Gram-positive Bacillus megaterium and that 3 has moderate herbicidal and antibacterial activities.

Inhibitors of Nitric Oxide Production from the Rhizomes of Alpinia galanga: Structures of New 8–9′ Linked Neolignans and Sesquineolignan

Abstract: The 80% aqueous acetone extract from the rhizomes of Alpinia galanga showed nitric oxide (NO) production inhibitory activities in mouse peritoneal macrophages. From the aqueous acetone extract, three new 8-9' linked neolignans, galanganal, galanganols A and B, and a sesquineolignan, galanganol C, were isolated together with nine known phenylpropanoids and p-hydroxybenzaldehyde. The structures of new neolignans were determined on the basis of physicochemical and chemical evidence. In addition, the inhibitory effects of the constituents from the rhizomes of A. galanga on NO production induced by lipopolysaccharide in mouse peritoneal macrophages were examined. Among them, galanganal (IC50=68 microM), galanganols B (88 microM) and C (33 microM), 1'S-1'-acetoxychavicol acetate (2.3 microM), 1'S-1'-acetoxyeugenol acetate (11 microM), trans-p-hydroxycinnamaldehyde (ca. 20 microM), trans-p-coumaryl alcohol (72 microM), and trans-p-coumaryl diacetate (19 microM) were found to show inhibitory activity.

Two New Aromatic Compounds from Hericium erinaceum (B ULL .: F R .) P ERS .

Abstract: 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.

Myrothenones A and B, cyclopentenone derivatives with tyrosinase inhibitory activity from the marine-derived fungus Myrothecium sp.

Abstract: New 3-amino-5-ethenylcyclopentenones, myrothenones A (4) and B (5), were isolated together with known 6-n-pentyl-α-pyrone (1), trichodenone A (2), and cyclonerodiol (3) from the marine algicolous fungus of genus of Myrothecium. The structure and absolute stereochemistry of the new compounds were established by spectral interpretation and X-ray analysis. Compounds 1 and 4 exhibited a tyrosinase inhibitory activity with IC50 value of 0.8 and 6.6 μM, respectively, which are more active than kojic acid (IC50, 7.7 μM) currently being used as a functional personal-care compound.

Development of new synthetic methods and its application to total synthesis of nitrogen-containing bioactive natural products

Abstract: A group of naturally occurring substances containing nitrogen is widely distributed in plants as well as in fungi, animal, marine organisms, and insects, and many exhibit significant biological activity. These natural products with a huge variety of chemical structures include antibiotics, antitumor agents, immunostimulants, drugs affecting the cardiovascular and central nervous systems, analgesics etc. The diverse activities and low natural abundance of this group of natural products when coupled with their molecular complexity warrant development of new and efficient synthetic methods and strategy for the total synthesis of these products, in particular alkaloids. The purpose of this review is to describe some of our achievements in the total synthesis of the naturally-occurring bases including the Dendrobatid alkaloids pumiliotoxin B and allopumiliotoxin A, the anitibiotic streptazolin, the tricyclic marine alkaloids isolated from the ascidians such as fasicularin, lepadiformine, and cylindricine C, and the dimeric monoterpene alkaloid incarvillateine as well as the formal total synthesis of the spirocyclic marine alkaloids halichlorine and pinnaic acid, which are isolated from the Japanese marine sponge and the Okinawan bivalve, respectively.