Ayumi Ohsaki

The isolation and in vivo Potent Antitumor activity of clerodane diterpenoid from the oleoresin of the brazilian medicinal plant, copaifera langsdorfi desfon.

Abstract An extremely potent antitumor neo -clerodane diterpene was isolated from the oleoresin of the Brazilian medicinal plant, Copaifera langsdorfii Desfon. This compound was identified as (-)-kolavenol 1 . The antitumor effect of 1 against IMC carcinomas as determined from the increase in lifespan (I.L.S.) in mice was twice that of 5-FU. The structure elucidation and the antitumor activity of the other related compounds 2 ∼ 6 in this oleoresin were also described.

Microanalysis of a selective potent anti-Helicobacter pylori compound in a Brazilian medicinal plant, Myroxylon peruiferum and the activity of analogues.

A selective potent anti-Helicobacter pylori isoflavone was isolated from a Brazilian Medicinal Plant, Myroxylon peruiferum. The isolation bioassay-guided and the characterization of an active anti-H. pylori constituent was performed using the methanol extract of plant of minute amount. The active compound was identified as cabreuvin (1), an isoflavone derivative. The structure-activity relationships of several related compounds were also investigated.

Brartemicin, an inhibitor of tumor cell invasion from the actinomycete Nonomuraea sp.

Brartemicin (1), a new trehalose-derived metabolite, was isolated from the culture broth of the actinomycete of the genus Nonomuraea. Its structure and absolute configuration were determined by spectroscopic analyses. The new compound inhibited the invasion of murine colon carcinoma 26-L5 cells with an IC(50) value of 0.39 microM in a concentration-dependent manner without showing cytotoxic effects.

Hypaphorine, an indole alkaloid from Erythrina velutina, induced sleep on normal mice

An indole alkaloid (hypaphorine (1)) was isolated from Brazilian medicinal plant, Erythrina velutina (Leguminosae). This compound was investigated for sleep promoting effects in mice, and the results showed that it significantly increased non-rapid eye movement (NREM) sleep time during the first hour after its administration. The NREM sleep time was enhanced by 33% in the experimental mice when compared to that of the controls. This study therefore confirmed its sleep promoting property.

Echinophyllins A and B, novel nitrogen-containing clerodane diterpenoids from Echinodorus macrophyllus

Two novel nitrogen-containing clerodane diterpenoids, echinophyllins A (1) and B (2), were isolated from the leaves of the Brazilian medicinal plant Echinodorus macrophyllus (‘Chapeu-de-couro’), and their structures and relative stereochemistry were elucidated by spectroscopic data. Echinophyllins A (1) and B (2) possess a unique α,β-unsaturated γ-lactam ring consisting of a clerodane diterpene and a tyramine unit or N-feruloyl putrescine unit, respectively.

Chemical and genetic study of Ligularia duciformis and related species in Sichuan and Yunnan Provinces of China.

The chemical constituents of the root extracts and the evolutionarily neutral DNA base sequences were studied for 28 samples of Ligularia duciformis, L. kongkalingensis, and L. nelumbifolia collected in Sichuan and Yunnan Provinces of China. The samples could be classified into four chemotypes (1–4). Sesquiterpenoids having eremophilane and oplopane skeletons were isolated from two (Chemotype 1) and three (Chemotype 2) samples, respectively. Two new oplopane derivatives were isolated and their structures were determined. In 18 samples, phenylpropenoids were the major components (Chemotype 3). In five samples, neither phenylpropenoids nor sesquiterpenoids were found (Chemotype 4). Despite this large chemical variety, no correlation was found between the chemotype and the morphological criteria of species identification. The analysis of the evolutionarily neutral DNA regions also indicated that the samples were not separated into distinct clades and that introgression was extensive.

Idebenone Acts against Growth of Helicobacter pylori by Inhibiting Its Respiration

ABSTRACT Growth of Helicobacter pylori was inhibited by the quinones, idebenone, duroquinone, menadione, juglone, and coenzyme Q1 at low concentrations of 0.8 to 3.2 μg/ml. Idebenone specifically inhibited H. pylori growth by inhibiting respiration and decreasing the cellular ATP level. The respiratory inhibition was accompanied by reduction of idebenone by the H. pylori cells.

Clerodane diterpenoids from Portulaca cv jewel

Three trans-clerodane diterpenes were isolated from the aerial part of the Portulaca cv Jewel. Their structures were elucidated by spectroscopic methods and chemical correlations.

TRAIL-enhancing activity of Erythrinan alkaloids from Erythrina velutina

A new Erythrinan alkaloid (1), erythodine N-oxide, was isolated from the seeds of Erythrina velutina together with seven known Erythrinan alkaloids (2-7, 9) and an indole alkaloid (8). The structure of new compound (1) was elucidated by spectroscopic methods. Six of the nine compounds showed enhanced activity when combined with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Erysotrine (4) did not show cytotoxic activity by itself, but exhibited significant cytotoxicity when combined with TRAIL.

Minor diterpenoids from Portulaca cv Jewel

Abstract A trans -clerodane and a diterpenoid with the bicyclo[5.4.0]undecane skeleton were isolated from the aerial part of Portulaca cv Jewel, and their structures were elucidated by spectroscopic methods, chemical correlation and X-ray diffraction analysis. The chemotaxonomical significance is discussed.