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Biomedical subjects

T Nohara

Publications and source records attributed to T Nohara.

At least 91 records · Page 5Linked to original sources

Five new triterpene glycosides from Wisteria brachybotrys (Leguminosae).

From the vines of Wisteria brachybotrys (Leguminosae), five new oleanene glycosides, called wistariasaponins YC1,2, B3 and A2,3, together with four known ones were isolated. Their structures have been elucidated to be 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranosyl-(1-->2)-beta-D- glucuronopyranosyl yunganogenin C 21-O-beta-D-glucopyranoside (1), 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->2)-beta -D- glucuronopyranosyl yunganogenin C 21-O-beta-D-glucopyranoside (2), 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranosyl-(1-->2)-beta- -D-glucuronopyranosyl wistariasapogenol B 30-O-beta-D-glucopyranoside (3), 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranosyl-(1-->2)-beta-D- glucuronopyranosyl wistartiasapogenol A 30-O-beta-D-glucopyranoside (4) and 3-O-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl wistariasapogenol A 30-O-beta-D-glucopyranoside (5), respectively.

Carbohydrate Sequence↗

Transient bacteremia after tooth extraction with intravenous cefuroxime prophylaxis.

Twenty-four blood samples obtained after tooth extraction with intravenous cefuroxime prophylaxis were cultured on Bactec NR16A and NR 17A (Becton Dickinson, Maryland, U. S. A.). MIC of identified microbes and the serum levels of cefuroxime were also measured. The overall incidence of bacteremia was 16.7% (four out of 24). Although nine strains were isolated, no streptococcal bacteremia occurred. The MICs of cefuroxime varied from 0.05 to 12.5 micrograms/ml, and serum levels ranged from 100 to 233 micrograms/ml, which were satisfactory concentrations for the microorganisms isolated. The results suggested that intravenous cefuroxime prophylaxis for tooth extraction reduced the incidence of bacteremia, as well as the isolation rate of streptococci, significantly.

Adult↗

Identification of the SecA protein homolog in pea chloroplasts and its possible involvement in thylakoidal protein transport.

Recently, we identified the SecA and SecY proteins in the cyanobacterium Synechococcus PCC7942. Antibodies raised against cyanobacterial SecA specifically reacted with a 110-kDa protein of pea chloroplasts, suggesting the presence of SecA in higher plant chloroplasts. A part of the pea secA cDNA was polymerase chain reaction-amplified with degenerated oligonucleotide primers and with pea cDNA as a template. The deduced amino acid sequence shows 62% identity with cyanobacterial SecA and 52% identity with Escherichia coli SecA. Antibodies raised against the pea SecA fragment, which was expressed in E. coli cells from the obtained polymerase chain reaction-amplified cDNA, reacted with the 110-kDa chloroplast protein; the 110-kDa protein was mainly found in the stroma but partly in the thylakoid membrane. The anti-pea SecA IgG inhibited the in vitro import of the 33-kDa protein of the oxygen-evolving complex, but not of the 23-kDa protein of the oxygen-evolving complex, into thylakoids. These results suggest that SecA facilitates transport of a subset of thylakoid lumenal proteins including the 33-kDa protein into thylakoids. We propose that a bacterial-type Sec protein-dependent transport system operates for protein transport into thylakoids in higher plant chloroplasts.

Amino Acid Sequence↗

Identification and characterization of the sec-A protein homologue in the cyanobacterium Synechococcus PCC7942.

The secA gene product mediates protein translocation across the cytoplasmic membrane in Escherichia coli. We have cloned a gene homologous to secA from the genome of the cyanobacterium Synechococcus PCC7942. The deduced amino acid sequence, 948 amino acids long, shows 43% homology with that of the E. coli secA and 47-48% homology with those of the algal plastid secA genes. Upon subcellular fractionation, the cyanobacterial SecA protein was mainly found as soluble homodimer in the cytosol, but the remaining small but distinct fraction was associated with both the cytoplasmic and thylakoid membranes. The SecA protein likely participates in protein translocation across both the cytoplasmic and thylakoid membranes in cyanobacterial cells.

Adenosine Triphosphatases↗

Ergostane glycosides from Petunia hybrida.

Six new ergostane glycosides, designated as petunioside A, petunioside B, 24-epipetunioside B, petunioside C, 24-epipetunioside C and petunioside D, were isolated from the methanolic extract of the fresh aerial parts of Petunia hybrida. Their structures were determined by means of spectroscopic analysis and single crystal X-ray analysis.

Carbohydrate Conformation↗

Steroidal glycosides from Capsicum annuum.

Four new steroidal glycosides, named capsicosides A-D together with proto-degalactotigonin, were isolated from the roots and seeds of Capsicum annuum var. conoides and Capsicum annuum var. fasciculatum. On the basis of detailed chemical and spectroscopic evidence, the structures of capsicosides A-D were shown to be furostanol glycosides corresponding to gitogenin and tigogenin oligoglycosides. Capsicoside A was regarded as the same compound as the previously described capsicoside, whose structure now needs to be revised according to the data presented in this report.

Capsicum↗

Triterpene glycosides from thalictri herba. II.

Five new triterpene glycosides were isolated from the methanolic extract of Thalictri Herba (Takatogusa), the dried aerial parts of Thalictrum sp. plants (Ranunculaceae). They were designated as thalictosides III (1) and IV (2), being cycloartane-type glycosides, and thalictosides VI (3), VII (4) and VIII (5), being oleanene-type glycosides. By chemical and spectroscopic evidence, their structures were elucidated as 22R-21S,23R-epoxy- and 22R-21R,23R-epoxy-21-methoxycycloart-24-en-3 beta,22,30-triol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]- beta-D-glucopyranosides (1 and 2, respectively), 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L- rhamnopyranosyl-(1-->4)-beta-D-xylopyranosyl hederagenin 28-O-beta-D-glucopyranosyl ester (3) and 3-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->3)-alpha- L- rhamnopyranosyl-(1-->4)-beta-D-xylopyranosyl oleanolic acid and hederagenin 28-O-beta-D-glucopyranosyl esters (4 and 5, respectively).

Carbohydrate Sequence↗

Two new triterpenoidal glycosides from Medicago polymorpha L.

Two new triterpenoid glycosides called medicago-saponins P1 (1) and P2 (2) were isolated together with five known glycosides from the aerial parts of Medicago polymorpha L. (Leguminosae). The structures of 1 and 2 were determined to be 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl caulophyllogenin 28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside and the desglucoside of 1.

Carbohydrate Sequence↗

Five new triterpene glycosides from Russell lupine.

In a continuing study on the ingredients of Lupinus genus, we examined the oligoglycoside constituents of the Russell lupine (L. polyphyllus x L. arboreus hybrid). Five new oleanene glycosides, called Lupinosides PA1-5 (1-5), together with three known ones were isolated. Their structures of 1-5 were determined to be 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl- (1-->2)-beta-D-glucuronopyranosyl soyasapogenol A 21-O-beta-D- xylopyranoside (1), 3-O-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl soyasapogenol A 21-O-beta-D-xylopyranoside (2), 3- O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->2)-beta-D -glucuronopyranosyl kudzusapogenol A 21-O-beta-D- xylopyranoside (3), 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D- galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl soyasapogenol B 22-O-alpha-L-rhamnopyranoside (4), and 3-O-alpha-L-rhamnopyranosyl-(1-->2)- beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl soyasapogenol B 22-O- beta-D-glucopyranosyl-(1-->4)-alpha-L-rhamnopyranoside (5), respectively.

Carbohydrate Sequence↗

Effect of Desmodium styracifolium-triterpenoid on calcium oxalate renal stones.

We have studied the inhibitory effects of Desmodium styracifolium-triterpenoid (Ds-t) (extracted from Desmodium styracifolium (Osbeck) Merr, a herbal medicine) on the formation of calcium oxalate renal stones induced experimentally by ethylene glycol (EG) and 1 alpha(OH)D3 (1 alpha D3) in rats. The incidence of urinary stone formation was 81% in the control group, which received EG and 1 alpha D3, and 29% in the Ds-t group, which received EG and 1 alpha D3 supplemented by Ds-t. The serum calcium (Ca) concentration in the Ds-t group was significantly elevated and urinary Ca excretion was markedly reduced. Urinary excretion of citrate (Cit), a factor that prevents stone formation, was significantly increased in the Ds-t group. Excretion of urinary phosphorus (P), which was elevated to a significantly greater extent in the controls than in the Ds-t group, was increased in both groups. The increase in urine volume in the Ds-t group was significantly greater than in the control group. The 24-h creatinine clearance rate (Ccr) was significantly lower in the controls. These findings suggest that Ds-t inhibits the formation of Ca oxalate stones in rat kidneys by increasing the output of urine, decreasing the excretion of calcium and increasing the urinary excretion of citrate. Ds-t may be useful in preventing the recurrence of urinary Ca oxalate stones in the clinical setting.

Animals↗

Triterpene glycosides from the bark of Robinia pseudo-acacia L. II.

From the bark of Robinia pseudo-acacia L., six new triterpene glycosides, Robiniosides E--J, were isolated and their structures were elucidated as abrisapogenol B 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D - glucuronopyranoside (1), abrisapogenol B 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D- glucopyranosyl(1-->2)-beta-D-glucuronopyranoside (2), 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D - glucuronopyranosyl abrisapogenol B 22-O-alpha-L-rhamnopyranoside (3), 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D- glucopyranosyl(1-->2)-beta-D-glucuronopyranosyl abrisapogenol B 22-O-alpha-L-rhamnopyranoside (4), 3-O-alpha-L- rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D-glucuron opyranosyl abrisapogenol E 30-O-beta-D-apiofuranosyl(1-->6)-beta-D-glucopyranoside (5) and 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl(1-->2)-beta-D- glucuronopyranosyl abrisapogenol E 30-O-beta-D-apiofuranosyl(1-->6)-beta-D-glucopyranoside (6), respectively.

Carbohydrate Sequence↗

Two new steroidal saponins from dried fermented residues of leaf-juices of Agave sisalana forma Dong No. 1.

In a previous paper, we reported the isolation and structure determination of three new steroidal saponins, dongnosides C (3), D (2) and E (1) from the dried fermented residues of leaf-juices of Agave sisalana forma Dong No. 1. In a continuing study on this plant, two additional new major steroidal saponins, named dongnosides B (4) and A (5), were obtained. Their structures were characterized respectively as tigogenin 3-O-alpha-L-rhamonpyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->2)- [beta-D- glucopyranosyl-(1-->3)]-beta-D-glucopyranosyl-(1-->4)-beta-D-galactop yranoside and 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->2)-[beta- D- xylopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->3)]-beta-D- glucopyranosyl-(1-->4)-beta-D-galactopyranoside on the basis of chemical and physicochemical evidence.

Carbohydrate Sequence↗

Cyclic peptides, acyclic diterpene glycosides and other compounds from Lycium chinense Mill.

The chemical structures of four cyclic peptides, lyciumins A-D (1-4), three acyclic diterpene glycosides, lyciumosides I-III (5-7) and other three compounds, a tryptophan derivative glycoside (8), a monoterpene glycoside (9) and a steroidal glycoside (10) isolated from Lycium chinense, have been elucidated by a combination of chemical, 1H- and 13C-NMR, and mass spectrometric studies. Lyciumins are interesting because of their monocyclic octapeptides containing a novel C-N linkage between tryprophan N1 and glycine C alpha.

Amino Acid Sequence↗

Three new oleanene glycosides from Sophora flavescens.

Three new oleanene glycosides, sophoraflavosides II-IV (2-4) were isolated together with sophoraflavoside I (1) as the corresponding methyl ester forms from Sophorae Radix, the fresh roots of Sophora flavescens AITON (Leguminosae). Their structures have been elucidated as oxytrogenin 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->2)-beta -D- glucuronopyranoside (2), 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->2)-beta -D-glucuronopyranosyl oxytrogenin 22-O-alpha-L-arabinopyranoside (3) and 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->2)-beta -D-glucuronopyranosyl oxytrogenin 22-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranoside (4), along with unambiguous characterization as 3 beta,22 beta,24-trihydroxyolean-12-en-29-oic acid for their sapogenol, named oxytrogenin (5) on the bases of chemical reactions and spectral analyses.

Carbohydrate Sequence↗

Triterpene glycosides from the bark of Robinia pseudo-acacia L. I.

From the bark of Robinia pseudo-acacia L., five new triterpene glycosides, robiniosides A-D (3, 5-7) and compound III (4), were isolated and their structures were elucidated as 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl(1-->2)-beta-D- glucuronopyranosyl 3 beta,22 beta-dihydroxyolean-12-en-29-oic acid (3), 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D -glucuronopyranosyl 3 beta,22 beta,24-trihydroxyolean-12-en-29-oic acid (4), whose sapogenol was unambiguously characterized and designated as oxytrogenin, 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl(1-->2)-beta-D glucuronopyranosyl oxytrogen (5), 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl oxytrogenin 22-O-alpha-L-rhamnopyranoside (6), 3-O-alpha-L- rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl(1-->2)-beta-D-glucuronop yranosyl oxytrogenin 22-O-alpha-L-rhamnopyranoside (7), respectively, together with two known triterpene glycosides, kaikasaponin III (1) and 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D - glucuronopyranosyl 3 beta,22 beta-dihydroxyolean-12-en-29-oic acid (2).

Carbohydrate Sequence↗

Six new triterpenoidal glycosides including two new sapogenols from Albizziae Cortex. V.

Six new triterpenoid glycosides called julibrosides A1-A4, B1 and C1 were isolated from Albizziae Cortex, the dried stem bark of Albizzia julibrissin Durazz. Their structures were determined based on spectral and chemical evidence. Julibrosides B1 and C1 had new sapogenols, designated julibrogenin B and C, respectively, while julibrosides A3 included N-acetyl-D-glucosamine as a sugar component.

Carbohydrate Sequence↗

Triterpene glycosides from the seeds of Astragalus sinicus L.

From the seeds of Astragalus sinicus L. (Leguminosae), seven triterpene glycosides were isolated and identified as soyasaponin I-III methyl esters (1-3) which were treated with CH2N2 during the separation procedure, soyasaponin IV (4), soyasapogenol B 3-O-beta-D-glucuronopyranoside (5), 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-xylopyranosyl(1-->2)-beta-D- glucuronopyranosyl 3 beta, 22 beta, 24-trihydroxy-11-oxoolean-12-ene (6), whose sapogenol (8) was obtained by enzymatic hydrolysis using glycyrrhizinic acid hydrolase, unambiguously characterized and designated as complogenin, and 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D - glucuronopyranosyl complogenin (7).

Glycosides↗