Biomedical subjects

T Nohara

Publications and source records attributed to T Nohara.

At least 55 records · Page 3Linked to original sources

PubMed1999

Phenethyl alcohol glycosides and isopentenol glycoside from fruit of Bupleurum falcatum.

Investigation on the constituents of the fruit of Bupleurum falcatum L. resulted in the isolation of the three new glycosides, phenethyl alcohol 8-O-beta-D-glucopyranosyl-(1-->2)-O-beta-D-apiofuranosyl-(1-->6)-b eta-D- glucopyranoside, phenethyl alcohol 8-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside and isopentenol 1-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside along with five known glycosides, icariside D1, icariside F2, saikosaponin a, saikosaponin c and saikosaponin d. The structures of these compounds were elucidated on the basis of interpretation of chemical and spectral data.

Carbohydrate Conformation↗

PubMed1999

Strong antinociceptive effect of incarvillateine, a novel monoterpene alkaloid from Incarvillea sinensis.

Incarvillea sinensis is a wild plant distributed in northern China. The dried whole plant has been traditionally used to treat rheumatism and relieve pain as an ancient Chinese crude drug. To investigate its antinociceptive activity, we evaluated several fractions derived from the methanolic extract of Incarvillea sinensis in the formalin-induced pain model in mice. Incarvillateine, a novel monoterpene alkaloid, has been found to show significant antinociceptive activity. Here we report the antinociceptive activity of incarvillateine and compare its activity with that of morphine. Additionally, we suggest that its action may be related to influence on the central opioid pathways.

Alkaloids↗

PubMed1999

Diterpenes from the fruits of Vitex rotundifolia.

Eight new labdane-type diterpenes (1-8) were isolated from the fruit of Vitex rotundifolia along with two known abietane-type diterpenoids (9, 10), and their structures were characterized on the basis of spectroscopic data and X-ray crystallographic analysis. Among them, the abietane-type diterpenoid ferruginol (9) exhibited a stronger antioxidative activity than the standard antioxidant, 3-tert-butyl-4-hydroxyanisole (BHA), using a ferric thiocyanate method.

Antioxidants↗

PubMed1999

Study of structure--hepatoprotective relationships of oleanene-type triterpenoidal glucuronides obtained from several fabaceous plants on rat primary hepatocyte cultures.

The protective effects of nine oleanene-type triterpenoidal glucuronides obtained from several fabaceous plants (Lupinus polyphyllus x arboreus Hybrid, Astragalus complanatus, Wistaria brachybotrys) on in vitro immunological liver injury in primary cultured rat hepatocytes were studied. Although all tested saponins showed hepatoprotective action, the levels of activity of the individual saponins differed. Structure-activity relationships for the sapogenol moiety suggested that the presence of the carbonyl group at C-22 would show a similar hepatoprotective effect to that of the hydroxyl group at C-22 while the presence of the hydroxyl group at C-30 would reduce the hepatoprotective action. This structure-activity relationship substantiated other recently obtained data. Furthermore, the beta-orientation of the hydroxyl group at C-21 is more effective than the alpha-configuration in regard to the hepatoprotection. Furthermore, structure-activity relationships for the sugar moiety substantiated previously obtained data that the hydroxyl group at C-5" enhances the hepatoprotective action.

Animals↗

PubMed1999

Hepatoprotective and hepatotoxic actions of oleanolic acid-type triterpenoidal glucuronides on rat primary hepatocyte cultures.

The protective effects of oleanolic acid-type saponins and their derivatives on in vitro immunological liver injury of primary cultured rat hepatocytes were studied. A known antihepatotoxic saponin (chikusetsusaponin IVa, 1) showed hepatoprotective activity in this model. Although a rhamnosyl derivative (2) of 1 similarly showed hepatoprotective activity, its prosapogenin (5) did not show any hepatoprotective activity. On the contrary, 5 exhibited cytotoxicity toward liver cells. In the absence of antiserum, monodesmosyl saponins showed hepatotoxicity, while the bisdesmosyl saponins except for 1, did not show such hepatotoxicity. In order to clarify the effects of the sugar residues at C-3 and C-28 responsible for hepatoprotective and hepatotoxic actions, oleanolic acid 3-O-glucuronide (2a) and oleanolic acid 28-O-glucoside (2b) were prepared and tested. 2b showed neither hepatoprotective action nor hepatotoxicity. In contrast, 2a was effective at 90 microM on hepatoprotection, although it showed strong hepatotoxicity. Oleanolic acid (2c) itself showed both hepatoprotective action and weak hepatotoxicity. Therefore, the hepatoprotective activity of these types of saponins could represent a balance between hepatoprotective action and hepatotoxicity.

Animals↗

PubMed1999

HPLC profile analysis of hepatoprotective oleanene-glucuronides in Puerariae Flos.

In order to confirm the constitution of hepatoprotective oleanene glucuronide (OG), HPLC profile analyses of the total OG fractions of both Puerariae Thomsonii Flos (the flowers of Pueraria thomsonii) and Puerariae Lobatae Flos (the flowers of P. lobata) were performed. No remarkable difference in the HPLC profiles with respect to OGs in the flowers was shown, in contrast to those of the roots. By repeated chromatography of the total OG fraction of Puerariae Thomsonii Flos, soyasaponin I (1), kaikasaponin III (2) and kakkasaponin I (3), which had been already isolated from Puerariae Lobatae Flos, were obtained. The hepatoprotective activity of 2 towards immunologically induced liver injury was significantly more effective than that of 1. This information supported previously obtained structure-hepatoprotective relationship data which was measured on another model. The structure-activity relationship information which suggested that the hydroxymethyl group of the galactosyl unit would enhance the hepatoprotective activity was also substantiated.

Animals↗

PubMed1998

Triterpenoidal saponins from Baptisia australis.

Extraction of the roots of Baptisia australis afforded a new triterpenoid saponin, baptisiasaponin I together with kaikasaponin III. The structure of baptisiasaponin I was elucidated as 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranosyl- (1-->2)-beta-D-glucuronopyranosyl sophoradiol on the basis of its spectral data and chemical degradation.

Carbohydrate Conformation↗

PubMed1998

Kaikasaponin III and soyasaponin I, major triterpene saponins of Abrus cantoniensis, act on GOT and GPT: influence on transaminase elevation of rat liver cells concomitantly exposed to CCl4 for one hour.

The antihepatotoxic activities of soyasaponin I and kaikasaponin III, triterpenoidal saponins isolated from Abri Herba, the whole plant of Abrus cantoniensis, were studied on liver injury induced by CCl4 in primary cultured rat hepatocytes. The antihepatotoxic activities of these saponins and glycyrrhizin (positive control) were demonstrated by measuring the levels of glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT). Soyasaponin I inhibited the elevation of GOT and GPT activities. The activities were comparable to those of glycyrrhizin. On the other hand, kaikasaponin III was more effective than soyasaponin I and glycyrrhizin. Kaikasaponin III showed the antihepatotoxic activity at less than 100 micrograms/ml. Furthermore, the highest activity was observed even in the lower doses (50, 100 micrograms/ml). However, soyasaponin I and kaikasaponin III showed some toxicity at the highest dose (500 micrograms/ml), though glycyrrhizin did not show toxicity at any dose.

Alanine Transaminase↗

PubMed1998

Structure-hepatoprotective relationships study of soyasaponins I-IV having soyasapogenol B as aglycone.

As a part of our study on the leguminous plants, we investigated the constituents of the aerial parts of Glycine soya. We isolated and identified four known saponins, soyasaponins I, II, III, and IV which have the same aglycone, soyasapogenol B. As a part of our studies concerning hepatoprotective drugs, we also examined the hepatoprotective actions of these saponins towards immunologically induced liver injury on primary cultured rat hepatocytes. The action of soyasaponin II was almost comparable with that of soyasaponin I, whereas those of soyasaponin III and IV were more effective than soyasaponins I and II. This means that the disaccharide group shows greater action than the trisaccharide group. Furthermore, the saponin having a hexosyl unit shows a slightly greater action than that of the pentosyl unit in each disaccharide group or trisaccharide group. Structure-activity relationships suggest that the sugar moiety linked at C-3 may play an important role in hepatoprotective actions of soybean saponins.

Animals↗

PubMed1998

Preventive effects of saponins from the Pueraria lobata root on in vitro immunological liver injury of rat primary hepatocyte cultures.

Preventive effects of nine saponins obtained from Puerariae Radix (the roots of Pueraria lobata) on in vitro immunological liver injury in primary cultured rat hepatocytes were studied. Although all tested saponins showed hepatoprotective action, the levels of activity of individual saponins differed. Structure-activity relationships for the sapogenol moiety suggested that the hydroxy group at C-29 would reduce the hepatoprotective activity while the hydroxy group at C-21 could enhance the hepatoprotective activity. Furthermore, structure-activity relationships for the sugar moiety suggested that the oxygen-bearing group at C-5" would enhance the hepatoprotective activity, though the configuration of the hydroxy group at C-3" could be less important for hepatoprotective activity.

Animals↗

PubMed1998

Structures of three new oleanene glucuronides isolated from Lathyrus palustris var. pilosus and hepatoprotective activity.

Three new saponins, named palustrosides I, II and III, together with azukisaponins II, V and soyasapogenol B monoglucuronide, were isolated from the aerial parts of Lathylus palustris L. var. pilosus Ledeb. The structures of palustrosides I, II and III were identified as 3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucuronopyranosides of soyasapogenol E, abrisapogenol E, and bredemolic acid 28-O-beta-D-glucopyranoside, respectively, by spectroscopic and chemical methods. As part of our studies on hepatoprotective drugs, we also examined the hepatoprotective effects of these saponins towards immunologically induced liver injury in primary cultured rat hepatocytes. The activity of the disaccharide group was greater than that of the trisaccharide group. This information regarding the structure-activity relationships substantiated previously obtained data. Structure-hepatoprotective relationships for the sapogenol moiety suggested that the hydroxyl group at C-30 reduces the hepatoprotective effect. On the other hand, the carbonyl group at C-22 may be equivalent to a hydroxyl group at C-22 in terms of hepatoprotective action. Oleanolic acid-type saponins also exhibited hepatoprotective action.

Animals↗

PubMed1998

Bile acids of Fel Ursi.

The first direct separation of Fel Ursi using octadecyl silica (ODS) open column chromatography has been accomplished and provided to provide several pure, free and conjugated bile acids, the structures of which were substantiated by spectroscopic methods.

Animals↗

PubMed1998

Partial hydrolysis of soyasaponin I and the hepatoprotective effects of the hydrolytic products. Study of the structure-hepatoprotective relationship of soyasapogenol B analogs.

As a part of our studies of hepatoprotective drugs, we prepared some soyasapogenol B analogs from soyasaponin I. We examined the hepatoprotective effects of these analogs, using immunologically-induced liver injury, in primary cultured rat hepatocytes. Soyasaponin III and soyasapogenol B monoglucuronide were more effective than soyasaponin I. Both compounds were significantly effective even at 30 microM. The action of soyasapogenol B was almost equal to that of soyasaponin I, although glucuronic acid did not show any activity even at the highest dose (500 microM). When the two compounds were mixed, the hepatoprotective action did not change, compared with soyasapogenol B. Therefore, we concluded that the linkage between glucuronic acid and soyasapogenol B could enhance the hepato-protective activity.

Animals↗

PubMed1998

A new oleanene glucuronide having a branched-chain sugar from Melilotus officinalis.

A new oleanene glucuronide called melilotus-saponin O1 (1) was isolated together with three known ones from the roots of Melilotus officinalis (L.) PALLAS (Leguminosae). The structure of 1 was determined to be 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1--> 3)]- beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl soyasapogenol B by spectroscopic and chemical methods.

Antiviral Agents↗

PubMed1998

HPLC profile analysis of oleanene-glucuronides in several edible beans.

HPLC analysis and yield of oleanene-glucuronide (OG) was done on some commercially available edible beans: seeds of Glycine max, Glycine max cv. Kuromame, Phaseolus vulgaris cv. Torosuku, Phaseolus vulgaris cv. Toramame, Phaseolus vulgaris cv. Taishokintoki, Phaseolus coccineus cv. Ooshirobana, Phaseolus coccineus cv. Murasakihanamame, Vigna unguiculata cv. Chuguro, Vigna angularis cv. Dainagon, Arachis hypogaea, Pisum sativum, and Vicia faba. All the beans listed above have OG, though in varying the amounts. Furthermore the HPLC profiles of beans belonging to the same genus were very similar except for that of the Vigna genus. There was no great difference of the HPLC profiles with respect to the cultivated varieties. The structures of the major OGs in each type of beans were identified as soyasaponins I (1) and V (2), and phaseoside I (3) (Phaseolus vulgaris and P. coccineus); 1 and soyasaponin II (4) (Glycine max); 1 and 2 (Vigna unguiculata); 1 (Pisum sativum, Arachis hypogaea and Vicia faba). In contrast, those in Dainagon (Vigna angularis cv. Dainagon) were identified as azukisaponins II (5) and VI (6).

Carbohydrate Sequence↗

PubMed1998

Prognostic value of tumor cell proliferation and intratumor microvessel density in advanced gastric cancer treated with curative surgery.

To clarify the prognostic value of tumor cell proliferation [proliferating cell nuclear antigen (PCNA)-positive rate assessed by anti-PCNA immunostaining] and intratumor microvessel density (/0.74 mm2, assessed by anti-CD34 immunostaining) in gastric cancer, 192 advanced gastric cancer patients who underwent curative surgery were investigated. Multivariate analysis showed that the following variables were significantly related to prognosis: age (P=0.029), depth of invasion (P=0.005), lymph node metastasis (P=0.006), lymphatic invasion (P=0.038), venous invasion (P=0.0005), PCNA-positive rate (P=0.049) and intratumor microvessel density (P=0. 011). In conclusion, tumor cell proliferation and intratumor microvessel density were independent prognostic factors in patients with advanced gastric cancer undergoing curative surgery.

Adult↗

PubMed1997

Cytotoxic glycosides from Albizia julibrissin.

During the course of a study of leguminous plants, cytotoxicity was demonstrated by the crude saponin fraction of Albizia julibrissin. Following chromatographic purification, the structures of three novel saponins, julibrosides I-III (1-3), inclusive of a cytotoxic principle, were elucidated. A comparison of the cytotoxicity of julibrosides (1-3) and their prosapogenins (4-15) prepared by alkaline hydrolysis clearly indicated that both an alpha-L-arabinofuranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->3)]-alpha- L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester unit and a monoterpene-quinovopyranosyl moiety are crucial substituents for cytotoxicity among this class of compounds. The hydroxy group at C-16 of aglycon may play an important role in mediating cytotoxicity, and the N-acetyl-glucosamine moiety at C-3 seems to enhance activity because 3 showed the strongest cytotoxicity.

Antineoplastic Agents, Phytogenic↗

PubMed1997

Pharmacological studies on Puerariae flos III: protective effects of kakkalide on ethanol-induced lethality and acute hepatic injury in mice.

Kakkalide, one of the major isoflavonoid components of Puerariae flos, has been investigated for its effect on ethanol-induced intoxication and on hepatic injury, including hyperglycaemia, in mice. Kakkalide reduced mortality associated with administration of ethanol. At doses of 100 and 200 mg kg-1 the effect of kakkalide was significant. The same dose of kakkalide prevented increased serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase activity. At a dose of 200 mg kg-1 it also counteracted ethanol-induced elevation of glucose levels. These results suggest that kakkalide might be useful for counteracting the effects of alcohol and might be effective for treating hepatic injury.

Acute Disease↗