Biomedical subjects

Hitoshi Tanaka

Publications and source records attributed to Hitoshi Tanaka.

22 records · Page 2Linked to original sources

PubMed2002

Isoflavonoids from the roots of Erythrina poeppigiana.

Five isoflavonoids, 7,4'-dihydroxy-2'-methoxy-8-(gamma,gamma-dimethylallyl)isoflav-3-ene, 4'-hydroxy-2'-methoxy-6",6"-dimethylpyran[2",3":7,8]isoflav-3-ene, 5,7,4'-trihydroxy-2'-methoxy-5'-(gamma,gamma-dimethylallyl)isoflavanone, 5,4'-dihydroxy-7,2'-dimethoxy-5'-(gamma,gamma-dimethylallyl)isoflavanone and 3,9-dihydroxy-4-(gamma,gamma-dimethylallyl)pterocarpene as well as six known compounds were isolated from the roots of Erythrina poeppigiana. Their structures were established on the basis of spectroscopic evidence.

Fabaceae↗

PubMed2002

Two diphenylpropan-1,2-diol syringates from the roots of Erythrina variegata.

Two new diphenylpropan-1,2-diols, eryvarinols A (1) and B (2), were isolated from the roots of Erythrina variegata. Their structures were elucidated as 1-(4-hydroxy-2-methoxyphenyl)-2-(4-hydroxy-3,5-dimethoxybenzoyloxy)-3-(4-hydroxyphenyl)propan-1-ol (1) and its 3"-prenyl derivative (2) on the basis of spectroscopic and chemical evidence. Both these compounds are unusual diphenylpropan-1,2-diols with a syringyl group.

Erythrina↗

PubMed2002

Peroxynitrite scavenging activities of aromatic compounds isolated from Konnyaku, Amorphophallus konjac K.Koch.

(+/-)-5,5'-Dimethoxysesamin, erythrinasinate, indole-3-carbaldehyde, (7R,8S)-dihydrodehydrodiconiferyl alcohol 9-O-beta-D-glucopyranoside, cis- and trans-N-(p-coumaroyl)serotonin, serotonin, 3,4-dihydroxybenzoic acid, and 3,4-dihydroxybenzaldehyde have been found in tobiko, a food by-product, and evaluation of their peroxynitrite scavenging activities has been done. Among these compounds, serotonin, trans-N-(p-coumaroyl)serotonin, 3,4-dihydroxybenzaldehyde, and 3,4-dihydroxybenzoic acid showed stronger activities than that of BHT (butylated hydroxytoluene) at 200 microM.

Amorphophallus↗

PubMedDate not supplied

Effects of oral squamous cell carcinoma-derived TGF-beta1 on CD26/DPPIV expression in T cells.

BACKGROUND: Enzymatic activity levels of serum CD26/dipeptidylpeptidase (DPP) IV in oral cancer patients are lower than those in healthy subjects. However, the mechanism for this decrease is not yet fully understood. MATERIALS AND METHODS: The influence of malignant cell-derived cytokines on cell surface CD26/DPPIV expression in human T cells was analyzed using an oral squamous cell carcinoma (SCC) cell line, KB, and peripheral blood T cells. RESULTS: Tumor growth factor (TGF)-beta1 in KB-conditioned medium (KBCM) down-regulated CD26/DPPIV expression in T cells, which was responsible for the decreased DPPIV activities in the cultured supernatant. Expression p27kip in T cells was maintained in addition to G1 arrest when cultured with KBCM but was abolished by inclusion of anti-TGF-beta1 antibody. CONCLUSION: SCC-derived TGF-beta1 down-regulates CD26/DPPIV expression in T cells, resulting in decreased serum CD26/DPPIV activity in oral cancer patients.

Carcinoma, Squamous Cell↗