Biomedical subjects

Jun Uzawa

Publications and source records attributed to Jun Uzawa.

5 recordsLinked to original sources

PubMed2006

Incorporation of selective population transfer and homo-spin decoupling into selective one-dimensional experiments.

The incorporation of selective population transfer (SPT) and homo-spin decoupling (HSD) into selective one-dimensional (1D) experiments has been shown to be very useful in obtaining information on the elucidation of the structure of organic compounds. To demonstrate this, the determination of the relative configuration of the sugar moiety of Mi-saponins has been presented.

Carbohydrate Sequence↗

PubMed2004

A new selective population transfer experiment using a double pulsed field gradient spin-echo.

A new pulse sequence is proposed for the determination of scalar coupling correlation in small- and medium-sized organic compounds. The method uses a combination of the double pulsed field gradient spin-echo (DPFGSE) and the selective population transfer (SPT) techniques and is shown to be useful in the analysis of complex spectra with many overlapped signals. The usefulness of this method in the structural elucidation of natural substances is demonstrated using strychnine and digitoxin as examples.

Digitoxin↗

PubMed2004

Antibacterial diterpenes and their fatty acid conjugates from rice leaves.

Six structurally oryzalide-related compounds, oryzadione (1), 2, 3, 4, 5 and 6, were isolated from a neutral fraction of the extract of healthy leaves using a bacterial leaf blight-resistant cultivar of a rice plant, "Norin-27", as a group of antimicrobial substances. Their structures were determined by spectroscopic studies to be kaurane analogues and kaurane analogues conjugated with fatty acids, i.e., 1: ent-15,16-epoxy-kauran-2,3-dione (enol form: ent-15,16-epoxy-2-hydroxy-kauran-1-en-3-one), 2: ent-15,16-epoxy-3beta-hydroxy-kauran-2-one, 3: ent-15,16-epoxy-3-oxa-kauran-2-one, 4: ent-15,16-epoxy-3beta-myristoyloxy-kauran-2-one, 5: ent-15,16-epoxy-3alpha-palmitoyloxy-kauran-2-one, and 6: ent-15,16-epoxy-2beta-palmitoyloxy-kauran-2-one.

Anti-Bacterial Agents↗

PubMed2004

Pregnane glycosides from the stems of Marsdenia tenacissima.

Four new pregnane glycosides, named marstenacissides A (1), B (2), C (3), and D (4), have been isolated from the stems of Marsdenia tenacissima. Their structures were established on the basis of chemical and spectral methods.

Glycosides↗

PubMed2002

A new triterpenoid saponin with inhibition of luteal cell from the seeds of Vaccaria segetalis.

A new triterpenoid saponin, named segetoside B, showing inhibition of luteal cell activity, has been isolated from the seeds of Vaccaria segetalis. On the basis of chemical reactions and spectral analyses, its structure has been established as 28-O-[beta-D-xylopyranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 2)]-[alpha-L-(5-O-acetyl)arabinofuranosyl-(1 --> 3)]-beta-D-(4-O-acetyl)fucopyranosyl-gypsogenin-3-O-beta-D-galactopyranosyl-(1 --> 2)-beta-D-(6-O-methyl ester)-glucuronopyranoside.

Animals↗