Biomedical subjects

Michiho Ito

Publications and source records attributed to Michiho Ito.

At least 19 recordsLinked to original sources

PubMed2006

Geraniol synthases from perilla and their taxonomical significance.

Geraniol synthases were isolated from five pure strains of Perilla citriodora and Perilla frutescens which vary in essential oil type, the main compounds of which were citral, elsholtziaketone, perillaketone, and perillene, respectively. This result supports the putative biosynthetic pathways of these three furylalkenes which are all produced by way of citral. Nucleotide sequences of geraniol synthases from three oil types of P. citriodora were identical, and almost the same as the sequence from P. frutescens, a species with twice the chromosome number of P. citriodora. This identity in sequence between P. citriodora and P. frutescens, together with other previous results, indicates that P. frutescens was formed as an amphidiploid of P. citriodora and an unknown wild species.

Acyclic Monoterpenes↗

PubMed2005

Antichagasic activity of komaroviquinone is due to generation of reactive oxygen species catalyzed by Trypanosoma cruzi old yellow enzyme.

A novel potent trypanocidal diterpene, komaroviquinone, was reduced by Trypanosoma cruzi old yellow enzyme (TcOYE) to its semiquinone radical. The reductase activity in trypanosome lysates was completely immunoabsorbed by anti-TcOYE antibody. Since TcOYE is expressed throughout the T. cruzi life cycle, komaroviquinone is an interesting candidate for developing new antichagasic drugs.

Animals↗

PubMed2004

New stilbene derivatives from Calligonum leucocladum.

Two new stilbene derivatives, (E)-resveratrol 3-(6' '-galloyl)-O-beta-D-glucopyranoside (1) and (E)-resveratrol 3-(4' '-acetyl)-O-beta-D-xylopyranoside (2), and five known stilbene derivatives (3-7) were isolated from the dried aerial parts of Calligonum leucocladum. Their structures were established on the basis of spectroscopic evidence. Compound 1 showed antioxidant activity and a restorative effect of the inhibition of oxacillin to oxacillin/methicillin-resistant Staphylococcus aureus.

Drug Resistance, Multiple↗

PubMed2004

Prenylated benzophenones and xanthones from Hypericum scabrum.

Two new polyprenylated benzophenones, a new polyprenylated phloroglucinol, and six new xanthone derivatives were isolated from the aerial parts of the Uzbekistan medicinal plant Hypericum scabrum. Their structures were elucidated on the basis of spectroscopic evidence. The isolated compounds showed moderate cytotoxicity for human tumor cells.

Antineoplastic Agents, Phytogenic↗

PubMed2004

cDNA isolation and functional expression of myrcene synthase from Perilla frutescens.

cDNA cloning of a monoterpene synthase from Perilla frutescens whose steam-distilled oil contains 92.9% perillaketone, was performed by the PCR method using primers designed based on limonene synthase. The full-length nucleotide sequence of this cDNA consisted of 1978 bp including a 1827-bp translational region encoding a deduced protein of 608 amino acids, which was similar to that of limonene synthase from P. frutescens (85% identity). Functional expression of this clone in Escherichia coli yielded an active monoterpene synthase enzyme, which converted geranyl diphosphate into 53.8% myrcene, 20.9% sabinene, 19.8% linalool and 5.5% limonene. As for the extraction of reaction products, we performed SPME (solid phase micro extraction) as well as conventional solvent extraction, and compared these two extraction methods.

Amino Acid Sequence↗

PubMed2004

Two new monoterpene glycosides and trypanocidal terpenoids from Dracocephalum kotschyi.

From the whole plant of Dracocephalum kotschyi BOISS., two new monoterpene glycosides (9, 10), together with seven known terpenoids and a phytosterol (1-8), were isolated. Their structures were determined to be limonen-10-al (1), geranial (2), neral (3), beta-sitosterol (4), oleanolic acid (5), ursolic acid (6), p-mentha-8-en-1,2-diol (7), colosolic acid (8), limonen-10-ol 10-O-beta-D-glucopyranoside (9), and limonen-10-ol 10-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside (10). Compounds 1 (3.1 microM), 2 (3.1 microM), 3 (3.1 microM), 5 (6.2 microM), 6 (6.2 microM), and 8 (6.2 microM) were effective against epimastigotes of Trypanosoma cruzi.

Animals↗

PubMed2004

New norditerpenoids with trypanocidal activity from Vitex trifolia.

Trypanocidal constituents of the fruits of Vitex trifolia were investigated. Activity-guided isolation of the acetone extract resulted in the isolation of two new norditerpene aldehydes, 1 and 2, together with five known diterpenes: vitexifolin E (3), vitexifolin F (4), vitexilactone (5), 6-acetoxy-9-hydroxy-13(14)-labden-16,15-olide (6), and previtexilactone (7). In vitro minimum lethal concentrations of the isolated compounds against epimastigotes of Trypanosoma cruzi were 11 microM (1), 36 microM (2), 34 microM (3), 34 microM (4), 66 microM (5), 66 microM (6), and >265 microM (7).

Animals↗

PubMed2004

New sesquiterpene hydroperoxides with trypanocidal activity from Pogostemon cablin.

Trypanocidal constituents of Pogostemon cablin were investigated. Activity guided isolation of the acetone extract resulted in isolation of three new sesquiterpene hydroperoxides 1-3, together with a known sesquiterpene, patchouli alcohol (4). In vitro minimum lethal concentrations of the hydroperoxides 1-3 against epimastigotes of Trypanosoma cruzi were 0.84 microM (1), 1.7 microM (2) and 1.7 microM (3). The activity of the corresponding alcohols and patchouli alcohol was very weak (MLC>200 microM).

Animals↗

PubMed2003

New icetexane and 20 norabietane diterpenes with trypanocidal activity from Dracocephalum komarovi.

Two new icetexane diterpenes, cyclocoulterone (1) and komaroviquinone (2), and a novel 20-norabietane diterpene, dracocephalone A (3), were isolated from Dracocephalum komarovi. Their structures were elucidated by extensive analyses of spectral data. Komaroviquinone (2) showed strong trypanocidal activity against epmastigotes of Trypanosoma cruzi, the causative agent of American trypanosomiasis, with a minimum lethal concentration of 0.4 micro M.

Animals↗

PubMed2003

Field survey of Glycyrrhiza plants in Central Asia (1). Characterization of G. uralensis, G. glabra and the putative intermediate collected in Kazakhstan.

The characteristics of Glycyrrhiza plants from 12 collection sites in southeastern Kazakhstan were investigated. G. uralensis was observed at 9 of the sites from Almaty to Shu, and G. glabra was observed at 8 sites. At 4 sites near Shu, and 1 site near Almaty, G. glabra and G. uralensis grew together forming a mixed population, and intermediate-type plants between them were also observed at 3 sites. Although two nucleotide substitutions of the chloroplast rbcL gene were observed between G. uralensis and G. glabra, rbcL sequences of the intermediate-types were divided into G. uralensis-type (G-A type) and G. glabra-type (A-T type). HPLC analysis of the roots indicated that species-specific flavonoids, glabridin and glycycoumarin, were detected in the roots of G. glabra and G. uralensis, respectively, but neither flavonoid was detected in underground parts of the intermediate-types. HPLC analysis of their leaves indicated a significant difference among G. uralensis, G. glabra and the intermediate-type plants. Both G. glabra-specific and G. uralensis-specific compounds were detected in the leaves of the intermediate-type, thus suggesting that the intermediate plants are hybrids of G. glabra and G. uralensis.

Chromatography, High Pressure Liquid↗

PubMed2003

Field survey of Glycyrrhiza plants in central Asia (2). Characterization of phenolics and their variation in the leaves of Glycyrrhiza plants collected in Kazakhstan.

A new prenylated flavanone, licoleafol, and a new prenylated dihydrostilbene, uralstilbene, together with four known compounds, 8-dimethylallyleriodictyol, sophoraflavanone B, gancaonin R, and 6-dimethylallyleriodictyol, were isolated from the leaves of Glycyrrhiza uralensis collected in Kazakhstan. HPLC analysis of the leaves of Glycyrrhiza plants collected in Kazakhstan showed that both G. uralensis-specific and Glycyrrhiza glabra-specific compounds were detected in the leaves of the morphologically intermediate-type plants, suggesting that the intermediate-type plant is a hybrid of G. glabra and G. uralensis. In addition, HPLC profiles of leaf extracts from offspring of intermediate-type plants were divided into the three types: the G. uralensis type, G. glabra type, and the intermediate type. From these results, it appears likely that the intermediate-type plant back-crosses with G. glabra and G. uralensis to generate a G. glabra-type plant and a G. uralensis-type plant, respectively.

Glycyrrhiza↗

PubMed2003

Field survey of Glycyrrhiza plants in Central Asia (3). Chemical characterization of G. glabra collected in Uzbekistan.

The chemical characteristics of Glycyrrhiza glabra L. were investigated at a habitat in Uzbekistan. HPLC analysis of the underground parts indicated that glycyrrhizin contents varied from 3.3 to 6.1% of dry weight, and that glabridin, a species-specific flavonoid for G. glabra, was detected in all underground samples (0.08-0.35% of dry weight). HPLC analysis of the leaves indicated that G. glabra plants collected in the present study could be divided into two types, RT-type and IQ-type, according to their major flavonol glycosides, rutin or isoquercitrin, respectively.

Asia, Central↗

PubMed2003

Four new 2-(2-phenylethyl)chromone derivatives from withered wood of Aquilaria sinensis.

Four new chromone derivatives, 5-hydroxy-6-methoxy-2-(2-phenylethyl)chromone (1), 6-hydroxy-2-(2-hydroxy-2-phenylethyl)chromone (2), 8-chloro-2-(2-phenylethyl)-5,6,7-trihydroxy-5,6,7,8-tetrahydrochromone (3), 6,7-dihydroxy-2-(2-phenylethyl)-5,6,7,8-tetrahydrochromone (4) were isolated from the MeOH extract of withered wood of Aquilaria sinensis, together with seven known constituents of agarwood.

Chromatography, Thin Layer↗

PubMed2002

Coumarins and gamma-pyrone derivatives from Prangos pabularia: antibacterial activity and inhibition of cytokine release.

The n-hexane and ethyl acetate extracts of the stems and the ethyl acetate extracts of roots from Prangos pabularia afforded an gamma-pyrone derivative and furanocoumarin derivatives with three glucose and gamma-pyrone (pabularin A, B and C), along with 26 previously known compounds (18 coumarins, six terpenoids and two glycosides). Their structures were established on the basis of spectroscopic studies. Of these, 16 coumarin derivatives isolated from P. pabularia were tested for antibacterial activity and inhibition of cytokine release.

Anti-Bacterial Agents↗

PubMed2002

Benzoylphloroglucinol derivatives from Hypericum scabrum.

Nine new polyprenylated benzoylphloroglucinol derivatives, hyperibones A-I (1-9), were isolated from the aerial parts of the Uzbekistan medicinal plant Hypericum scabrum. Their structures were determined mainly on the basis of spectroscopic evidence (2D NMR and HRMS). Compounds 1, 2, and 4 showed mild in vitro antibacterial activity against methicillin-resistance Staphylococus aureus (MRSA) and methicillin-sensitive Staphylococus aureus (MSSA).

Anti-Bacterial Agents↗

PubMed2002

Polysulfide derivatives from Ferula foetida.

The ethyl acetate-soluble fraction from a methanol extract of Ferula foetida has afforded six new sulfide derivatives, (E)-3-methylsulfinyl-2-propenyl sec-butyl disulfide (foetisulfide A) (1), (Z)-3-methylsulfinyloxy-2-propenyl sec-butyl disulfide (foetisulfide B) (2), (E)-3-methylsulfinyloxy-2-propenyl sec-butyl disulfide (foetisulfide C) (3), bis(3-methylthio-2E-propenyl) disulfide (foetisulfide D) (4), 3,4,5-trimethyl-2-thiophenecarboxylic acid (foetithiophene A) (5), 3,4,5-trimethyl-2-(methylsulfinyloxymethyl)thiophene (foetithiophene B) (6), along with six known compounds. The structures of 1-6 were established on the basis of spectroscopic studies, with the elucidation of 5 confirmed by single-crystal X-ray crystallography.

Chromatography, High Pressure Liquid↗

PubMed2002

Sesquiterpenes from Ferula penninervis.

The ethyl acetate soluble extract of the dried roots of Ferula penninervis gave 17 new sesquiterpenes [15 of the guaiane-type, ferupennins A-O (1-15), and two of the eudesmane-type, 1alpha-hydroxy-2-oxo-5alpha,7beta,11betaH-eudesm-3-en-6alpha,12-olide (16) and penninervin (17)] and nine known sesquiterpenes. The structures of the new compounds were elucidated on the basis of spectroscopic evidence and X-ray analysis. The absolute configuration of ferupennin A (1) was determined by a modified Mosher method.

Acetates↗

PubMed2002

An unusual sesquiterpene derivative from Ferula kuhistanica.

An unusual new sesquiterpene derivative, kuhistaferone (1), was isolated from the fruits of the Uzbekistan medicinal plant Ferula kuhistanica. The structure of 1 was established on the basis of spectroscopic evidence. Compound 1 showed moderate cytotoxicity against the human colon tumor cell line HCT116.

Anti-Bacterial Agents↗