Masao Hirotani

Cloning and expression of UDP-glucose: flavonoid 7-O-glucosyltransferase from hairy root cultures of Scutellaria baicalensis

Abstract. A cDNA encoding UDP-glucose: baicalein 7-O-glucosyltransferase (UBGT) was isolated from a cDNA library from hairy root cultures of Scutellaria baicalensis Georgi probed with a partial-length cDNA clone of a UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT) from grape (Vitis vinifera L.). The heterologous probe contained a glucosyltransferase consensus amino acid sequence which was also present in the Scutellaria cDNA clones. The complete nucleotide sequence of the 1688-bp cDNA insert was determined and the deduced amino acid sequences are presented. The nucleotide sequence analysis of UBGT revealed an open reading frame encoding a polypeptide of 476 amino acids with a calculated molecular mass of 53 094 Da. The reaction product for baicalein and UDP-glucose catalyzed by recombinant UBGT in Escherichia coli was identified as authentic baicalein 7-O-glucoside using high-performance liquid chromatography and proton nuclear magnetic resonance spectroscopy. The enzyme activities of recombinant UBGT expressed in  E. coli were also detected towards flavonoids such as baicalein, wogonin, apigenin, scutellarein, 7,4′-dihydroxyflavone and kaempferol, and phenolic compounds. The accumulation of UBGT mRNA in hairy roots was in response to wounding or salicylic acid treatments.

N6-(2-hydroxyethyl)adenosine, a biologically active compound from cultured mycelia of Cordyceps and Isaria species☆

Abstract The water-ethanol extracts of the cultured mycelia of 17 species of Cordyceps and six species of Isaria were each examined for the presence of

Flavonoids and phenylethanoids from hairy root cultures of Scutellaria baicalensis

We successfully established hairy root cultures of Scutellaria baicalensis by direct inoculation on sterile seedlings with Agrobacterium rhizogenes pRil5834 harbouring pBI121. Transformation was proved by direct detection of the inserted T-DNA by the polymerase chain reaction. To determine the optimal medium for growth of hairy roots, the effects of five basal media were investigated; growth was best in B5 liquid medium. A new flavone glucoside, 5,7,2′,6′-tetrahydroxyflavone 2′-O-β-d-glucopyranoside 15 known flavonoids and five known phenylethanoids were isolated from the hairy root cultures of S. baicalensis for the first time. Their structures were elucidated by various spectroscopic methods.

Ganoderic acid derivatives and ergosta-4,7,22-triene-3,6-dione from Ganoderma lucidum ☆

Abstract Seven new triterpenoids, ganoderic acid T, ganoderic acid S, ganoderic acid R, ganoderic acid P, ganoderic acid Q, ganoderic acid 0, 7-O-methyl-ganoderic acid 0 and a known ergosterol derivative, ergosta-4,7,22-triene-3,6-dione were isolated from the cultured mycelium of Ganoderma lucidum. The structure of the first compound was determined using spectroscopic and X-ray analysis, and the structures of the other compounds were elucidated by spectroscopic data.

Restoration of cardenolide-synthesis in redifferentiated shoots from callus cultures of Digitalis purpurea

Abstract No cardenolide was detected in cultured cells and roots of root forming callus of Digitalis purpurea under such conditions as addition of auxins, varied sugar concentration of the medium and illumination. Cardenolides such as digitoxin and purpurea glycoside A were found in leaves from the regenerated shoot from callus cultures. The manifestation of cardenolide-synthesizing potentiality seems to be closely related to some process of leaf development.

Astragalosides from hairy root cultures of Astragalus membranaceus

Abstract A new astragaloside, named agroastragaloside I and four known astragalosides, acetylastragaloside I, astragaloside I, astragaloside III and astragaloside IV were isolated from the hairy root cultures of Astragalus membranaceus . The structures of these compounds were elucidated by the spectroscopic data.

Production of ginsenoside saponins by culturing ginseng (Panax ginseng) embryogenic tissues in bioreactors

SummaryGinseng (Panax ginseng) embryogenic tissues were cultured in three types of reactors and the ginsenoside productivities in these tissues were compared. As a result, the saponin productivity was the best when an airlift reactor was used, and more than twice of that when a paddle or internal turbine reactor was used. The tissues grew 9 fold during 42 days, and the ginsenoside pattern resembled that of ginseng leaves.

Biotransformation of progesterone and pregnenolone by plant suspension cultures

Abstract Progesterone was converted to 5α-pregnanolone palmitate in high yield by tobacco ( Nicotiana tabacum var. Bright Yellow) and Sophora angustifolia callus tissues. In Sophora angustifolia callus, 5α-pregnanolone was detected at the same time. The results showed that progesterone undergoes stereospecific reduction of the α,β-unsaturated keto group and esterification. Pregnenolone was also converted to pregnenolone palmitate and 5α-pregnanolone palmitate by tobacco and Sophora angustifolia callus tissues.

Purification and characterization of UDP-glucuronate: baicalein 7-O-glucuronosyltransferase from Scutellaria baicalensis Georgi. cell suspension cultures.

UDP-glucuronate: baicalein 7-O-glucuronosyltransferase (UBGAT) catalyzes the transfer of glucuronic acid from UDP-glucuronic acid to the 7-OH of baicalein. UBGAT was purified from cultured cells of Scutellaria baicalensis Georgi (Lamiaceae). It was purified 95-fold using various chromatography and chromatofocusing procedures to apparent homogeneity. The Mr was estimated to be 110 kDa by gel filtration chromatography with a 52 kDa subunit by SDS-PAGE. The isoelectric point was pH 4.8. UBGAT was specific to UDP-glucuronic acid as a sugar donor and flavones with substitution ortho- to the 7-OH group such its baicalein (6-OH), scutellarein (6-OH) and wogonin (8-OMe).

A ganoderic acid derivative, a highly oxygenated lanostane-type triterpenoid from Ganoderma lucidum ☆

Abstract Ganoderic acid C, a new lanostane-type triterpenoid was isolated from the fruit body of Ganoderma lucidum. The structure of ganoderic acid C was elucidated by spectroscopic data and X-ray analysis of methyl ganoderate C acetate.