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Biomedical subjects

N Nagakura

Publications and source records attributed to N Nagakura.

At least 19 recordsLinked to original sources
PubMed2001

In vitro effects of E3040, a dual inhibitor of 5-lipoxygenase and thromboxane A(2) synthetase, on eicosanoid production.

In vitro pharmacological profiles of E3040, 6-hydroxy-5, 7-dimethyl-2-(methylamino)-4-(3-pyridylmethyl) benzothiazole were investigated. Against the 5-lipoxygenase activity of rat basophilic leukemia cells, E3040 and zileuton (a 5-lipoxygenase inhibitor) had an IC(50) of 0.23 and 0.93 microM, respectively. Against the thromboxane A(2) synthetase activity of human platelets, E3040 had an IC(50) of 0.01 microM, which was comparable to that of OKY-1581 (sodium (E)-3-[4-(3-pyridylmethyl) phenyl]-2-methylacrylate, a thromboxane A(2) synthetase inhibitor). Against cyclooxygenase activity of sheep seminal vesicles, E3040 showed no inhibition (IC(50), >300 microM). Sulfasalazine and 5-aminosalicylic acid, therapeutic drugs for inflammatory bowel disease, inhibited 5-lipoxygenase activity with an IC(50) of 293 and 970 microM, respectively. Sulfasalazine inhibited thromboxane A(2) synthetase activity with an IC(50) of 20 microM. In rat peritoneal leukocytes, E3040 inhibited leukotriene B(4) and thromboxane B(2) production with an IC(50) of 0.17 and 0.24 microM, respectively. E3040 inhibited leukotriene B(4) production in human neutrophils and thromboxane B(2) production in human platelets (IC(50) of 0.21 and 0.09 microM, respectively). These results indicated that E3040 potently inhibited 5-lipoxygenase and thromboxane A(2) synthetase and blocked leukotriene B(4) and thromboxane B(2) production in rat peritoneal and human blood cells.

Animals↗
PubMed2001

Tetrahydroisoquinoline-monoterpene and iridoid glycosides from Alangium lamarckii.

From the water soluble fraction of the dried fruits of Alangium lamrckii, four tetrahydroisoquinoline-monoterpene glycosides, 6-O-methyl-N-deacetylisoipecosidic acid, 7-O-methyl-N-deacetylisoipecosidic acid, 6,7-di-O-methyl-N-deacetylisoipecosidic acid and 6"-O-alpha-D-glucopyranosyl-6-O-methyl-N-deacetylisoipecosidic acid, and an iridoid glycoside, 6'-O-alpha-D-glucopyranosylloganic acid, were isolated, together with six known compounds. The structures of the previously unknown compounds were determined by spectroscopic and chemical means. The significance of these glucosides in the biogenesis of Alangium alkaloids is discussed; 6-O-methyl-N-deacetylisoipecosidic acid was also chemically converted into 10-O-demethylprotoemetine and dihydroisoalangine.

Asteraceae↗
PubMed2001

Dibenzofurans from the cultured lichen mycobionts of Lecanora cinereocarnea.

From the cultures of the spore-derived mycobionts of the lichen Lecanora cinereocarnea, five dibenzofurans, 3,7-dihydroxy-1,9-dimethyldibenzofuran, 2-chloro-3,7-dihydroxy-1,9-dimethyldibenzofuran, 2,8-dichloro-3,7-dihydroxy-1,9-dimethyldibenzofuran, 3-hydroxy-7-methoxy-1,9-dimethyldibenzofuran, and 2-chloro-7-hydroxy-3-methoxy-1,9-dimethyldibenzofuran, were isolated. Their structures were determined by spectroscopic methods.

Benzofurans↗
PubMed2001

Influence of natural and synthetic compounds on cell surface expression of cell adhesion molecules, ICAM-1 and VCAM-1.

Various natural and synthetic compounds including alkaloids, terpenoids and phenolics were tested for inhibition of the cell surface expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), both of which are crucial in the regulation of immune response and inflammation. Of 40 compounds tested, two compounds significantly downregulated the expression of VCAM-1 on murine endothelial cells (F-2) and ten compounds that of ICAM-1 on mouse myeloid leukemia cells (M1). Sanguinarine chloride (5) and isoliquiritigenin (13) were capable of lowering the levels of both ICAM-1 and VCAM-1. The structure-activity relationships study on chalcone and flavone derivatives related to 13 suggested that the inhibitory activity of the chalcone derivatives is attributable to the 4-hydroxy group as well as the possible coplanarity between the phenyl ring and the adjacent conjugated ketone.

Alkaloids↗
PubMed2001

Glycosides of benzyl and salicyl alcohols from Alangium chinense.

From the water-soluble fraction of the dried leaves of Alangium chinense, three new glycosides, benzyl alcohol beta-D-glucopyranosyl-(1 --> 2)-[beta-D-xylopyranosyl-(1 --> 6)]-beta-D-glucopyranoside, 2'-O-beta-D-glucopyranosylsalicin, and 2'-O-beta-D-glucopyranosyl-6'-O-beta-D-xylopyranosylsalicin were isolated along with seven known glycosides. The structures of the new compounds were determined by spectroscopic and chemical means.

Benzyl Alcohols↗
PubMed2000

Two Alangium alkaloids from Alangium lamarckii.

Two new Alangium alkaloids, 1',2'-dehydrotubulosine (1) and alangine (2), were isolated from the dried fruits of Alangium lamarckii along with tubulosine (3), isotubulosine (4), deoxytubulosine, cephaeline, isocephaeline, psychotrine, neocephaeline, 10-O-demethylcephaeline, 2'-N-(1"-deoxy-1" -beta-D-fructopyranosyl)cephaeline, protoemetine, protoemetinol, salsoline, and alangiside. The structures of the new alkaloids (1 and 2) were determined by spectroscopic and chemical means.

Alkaloids↗
PubMed2000

Five phenolic glycosides from Alangium chinense.

From the dried leaves of Alangium chinense, five novel phenolic glycosides, 6'-O-galloylsalicin (1); 4',6'-di-O-galloylsalicin (2); 4',6'-O-(S)-hexahydroxydiphenoylsalicin (3); 4', 6'-O-(R)-hexahydroxydiphenoylsalicin (4); and pyrocatechol 1-O-beta-D-xylopyranosyl(1-->6)-beta-D-glucopyranoside (5) were isolated. The structures of these new compounds were determined by spectroscopic methods.

Carbohydrate Conformation↗
PubMed2000

Quaternary isoquinoline alkaloids from Stephania cepharantha.

From the quaternary alkaloidal fraction of the dried tubers of Stephania cepharantha, two new isoquinoline alkaloids, stecepharine and tetradehydroreticuline have been isolated along with the known compounds, magnoflorine, menisperine, steponine, cyclanoline, oblongine, cis-N-methylcapaurine and 2'-N-methylisotetrandrine. cis-N-Methylcapaurine (=9-O-methylstecepharine) was isolated as a natural product for the first time. Their structures were determined on the basis of spectroscopic evidence.

Alkaloids↗
PubMed2000

A tetrahydroisoquinoline-monoterpene glucoside and an iridoid glucoside from Alangium kurzii.

From the leaves of Alangium kurzii, a new tetrahydroisoquinoline-monoterpene glucoside, 6-O-methyl-N-deacetylipecosidic acid and a new iridoid glucoside, 10-O-benzoyladoxosidic acid, were isolated along with alangiside, demethylalangiside, 6''-O-beta-D-glucosylhenryoside, uridine and four known flavonoid glycosides. The structures of new glucosides were determined on the basis of spectroscopic and chemical methods.

Acetylation↗
PubMed2000

Secoiridoid glucosides from Fraxinus americana.

Investigation of the leaves of Fraxinus americana led to the isolation of five secoiridoid glucosides, demethylligstroside, (2"R)- and (2"S)-2"-hydroxyoleuropeins, fraxamoside and frameroside, together with 18 known compounds. Their structures were determined on the basis of spectroscopic studies and chemical evidence.

Journal Article↗
PubMed2000

Secoiridoid glucosides from Fraxinus americana.

Investigation of the leaves of Fraxinus americana led to the isolation of five secoiridoid glucosides, demethylligstroside, (2"R)- and (2"S)-2"-hydroxyoleuropeins, fraxamoside and frameroside, together with 18 known compounds. Their structures were determined on the basis of spectroscopic studies and chemical evidence.

Glucosides↗
PubMed1999

Effects of ER-34122, a novel dual 5-lipoxygenase/cyclooxygenase inhibitor, on indices of early articular lesion in MRL/MpJ-lpr/lpr mice.

OBJECTIVE AND DESIGN: To investigate effects of ER-34122, a novel dual 5-lipoxygenase (LOX)/cyclooxygenase (COX) inhibitor, and indomethacin on progression of articular lesions in MRL/MpJ-lpr/lpr (MRL/1) mice. MATERIAL: 100 male MRL/l mice. TREATMENT: ER-34122 (1-100 mg/kg) and indomethacin (1 mg/kg) were orally administered once a day to MRL/l mice from 6 to 10 or 16 weeks old. METHODS: Articular lesions were analyzed histopathologically in the early (10 weeks old) or late (16 weeks old) stages of MRL/l mice arthritis. Serum levels of rheumatoid factor were measured by using enzyme-linked immunosorbent assay. RESULTS: Articular lesions in the late stage of MRL/l mice arthritis were characterized by cartilage degeneration and pannus formation which were severer than those in the early stage. Polymorphonuclear leukocyte (PMN) infiltration and subsynovial soft tissue edema were observed as characteristic lesions in the early stage. ER-34122 suppressed progression of PMN infiltration, subsynovial soft tissue edema and multiplication of synovial lining cells in the early stage of the arthritis, even though it had no significant effect on other indices of articular lesion, enlargement of lymph nodes and serum levels of rheumatoid factors. On indices of late articular lesion, ER-34122 had no significant beneficial effects. Neither in the early nor late stage, indomethacin, a COX inhibitor, had significant effect on the arthritis at the examined dose. CONCLUSIONS: These results disclosed that ER-34122, a dual LOX/COX inhibitor, has anti-inflammatory activity in the early stage of the spontaneous arthritis.

Animals↗
PubMed1999

Ipecac alkaloids from Cephaelis acuminata.

From the dried roots of Cephaelis acuminata, five ipecac alkaloids, neocephaeline, 7'-O-demethylcephaeline, 10-O-demethylcephaeline, 2'-N-(1"-deoxy-1"-beta-D-fructopyranosyl)cephaeline and 2'-N-(1"-deoxy-1"-beta-D-fructopyranosyl)neocephaeline, were isolated, along with emetine, cephaeline, psychotrine, protoemetine, 9-demethylprotoemetinol and isocephaeline. Structures were determined by spectroscopic and chemical means.

Ipecac↗
PubMed1999

Three secoiridoid glucosides from Jasminum nudiflorum.

Phytochemical study of the leaves and stems of Jasminum nudiflorum has led to the isolation of three secoiridoid glucosides, jasnudiflosides A-C (1-3). The structures of these compounds were elucidated on the basis of chemical and spectroscopic evidence.

Carbohydrate Conformation↗
PubMed1998

ER-34122, a novel dual 5-lipoxygenase/cyclooxygenase inhibitor with potent anti-inflammatory activity in an arachidonic acid-induced ear inflammation model.

OBJECTIVE AND DESIGN: To investigate the effect of ER-34122, a novel pyrazole derivative, on 5-lipoxygenase (LOX) and cyclooxygenase (COX) metabolite production in vitro, ex vivo and in vivo. MATERIAL: In vitro, lysate of rat basophilic leukemia cells, the microsome fraction of sheep seminal vesicles, human polymorphonuclear leukocytes, human synovial cells, and human monocytes. Ex vivo and in vivo, male Balb/c mice or SD rats. TREATMENT: In ex vivo study, ER-34122 (0.03-1 mg/kg) was orally administered 1 h before withdrawal of blood samples. In carrageenin-induced paw edema, ER-34122 (3-100 mg/kg) and indomethacin (1-10mg/kg) were orally administered 1 h before carrageenin injection. In arachidonic acid-induced ear inflammation, ER-34122 (0.3-10mg/kg), zileuton (10-100mg/kg) and indomethacin (0.3-3mg/kg) were orally administered 1 h before arachidonic acid application. METHODS: 5-Hydroxyeicosatetraenoic acid and other eicosanoids were determined by using an HPLC method and enzyme immunoassay, respectively. Rat hind paw edema and mouse ear edema were assessed by measuring paw volume and ear thickness, respectively. Myeloperoxidase (MPO) activity and eicosanoid content of the ear tissue were also determined. RESULTS: ER-34122 inhibited both LOX and COX product generation in vitro, and ex vivo. ER-34122 and indomethacin inhibited carrageenin-induced paw edema formation. In the arachidonic acid-induced ear inflammation, ER-34122 inhibited inflammatory responses (edema formation and MPO accumulation) as well as eicosanoids (LTB4, LTC4 and PGE2) generation. A representative LOX inhibitor, zileuton, also inhibited these inflammatory responses, while a COX inhibitor, indomethacin, did not suppress them though it completely inhibited PGE2 generation. CONCLUSIONS: The anti-inflammatory characteristics of ER-34122 are considered to be superior to those of COX inhibitors such as indomethacin, because in addition to its inhibitory activity on the COX pathway, ER-34122 inhibits LOX products generation, as revealed by the inhibition of edema formation or polymorphonuclear leukocyte infiltration in the arachidonic acid-induced ear inflammation model.

Animals↗
PubMed1997

Bisbenzylisoquinoline alkaloids from Stephania cepharantha and their effects on proliferation of cultured cells from the murine hair apparatus.

Bisbenzylisoquinoline alkaloids were isolated from Stephania cepharantha Hayata and their proliferative activities on cultured hair cells from the murine skin were evaluated. Cepharanthine (1), cepharanoline (9), isotetrandrine (2), and berbamine (7) showed significant activities in the range of 0.01-0.1 microgram/ml, but had no activity on cultured keratinocytes or fibroblasts from the murine skin.

Alkaloids↗