Identification of viruses infected in Rehmannia glutinosa Libosch. var purpurea Makino and effect of virus infection on root yield and iridoid glycoside contents

Virus free plants of Rehmannia glutinosa Libosch. var. purpurea Makino were obtained through meristem tip tissue cultures from plants infected with a mixture of tabocco mosaic virus(TMV), a member of the carlavirus group, and an unknown spherical virus. The re-infection rate of the virus free plants by TMV in the field was determined by enzyme linked immunosorbent assay(ELISA). Twenty seven percent of the plants were re-infected during the first year, 31 % by the end of second year, and 63 % by the end of the third year. The yield of root and iridoid glycoside contents gradually decreased each year. These results led to the conclusion that virus infection causes marked decrease of the yield of roots and productivity of secondary metabolites.     

Production of monoclonal antibodies and development of an ELISA for solamargine

The ratio of hapten and bovine serum albumin in an antigen conjugate was determined by matrix-assisted laser desorption/ionization mass spectrometry. A hybridoma secreting monoclonal antibodies against solamargine was produced by fusing splenocytes immunized with a solamargine-bovine serum albumin conjugate with HAT-sensitive mouse myeloma cell line, P3-X63-Ag8-653. Extensive cross-reaction of anti-solamargine antibodies against solasonine appeared. Aglycone of solamargine, solasodine cross-reacted with anti-solamargine antibodies resulting in a 43.8% cross-reaction. Insignificant cross-reaction appeared with tomatine (2.06%). The full measuring range of the assay extends from 57.5 pmol ml^–1 to 11.5 nmol ml^–1 of solamargine.     

A new biologically active phenolic from Cattleya trianaei

A new phenolic, hydroxyeucomic acid, and dopamine were isolated from Cattleya trianaei and their biological activities examined.     

Alkaloids from the seeds of Sterculia lychnophora (Pangdahai)

Two alkaloids, named sterculinine I and sterculinine II, together with thirteen known compounds were isolated from the ethanol extract of a well-known Chinese traditional drug, Pangdahai (the seeds of Sterculia lychnophora Hance). Their structures were elucidated by NMR, UV, IR and MS spectroscopic analysis.     

Steroid 5alpha-reductase inhibitory activity and hair regrowth effects of an extract from Boehmeria nipononivea

The acetone extract of Boehmeria nipononivea showed both potent 5alpha-reductase inhibitory activity and hair regrowth promotion effects on mice. 5alpha-Reductase inhibitory activity-guided fractionation led to six active fatty acids: alpha-linolenic, linoleic, palmitic, elaidic, oleic and stearic acids. The extract of B. nipononivea, and alphalinolenic, elaidic and stearic acids exhibited a hair regrowth effect.     

Flavonoids from Goodyera schlechtendaliana

A flavonol glycoside, 3-[[6-O-(6-deoxy-alpha-L-mannopyranosyl)-beta-D- glucopyranosyl]oxi]-5,7-dihydroxy-8-[(4-hydroxy-3,5-dimethoxyphenyl)meth yl]- 2-(3,4-dihydroxypheny)-4H-1-benzopyran-4-one, trivially named goodyerin, was isolated from the whole plant of Goodyera schlechtendaliana, along with three known flavonoids, rutin, kaempferol-3-O-rutinoside and isorhamnetin-3-O-rutinoside. The structures were established by spectroscopic analysis.     

High-throughput determination of free D-aspartic acid in mammals by enzyme immunoassay using specific monoclonal antibody

A method for rapid determination of free d-aspartic acid (d-Asp) in mammals has been established using a highly specific mouse monoclonal antibody against d-Asp for the first time. An anti-d-Asp monoclonal antibody was obtained by the immunization of bovine-serum-albumin-conjugated d-Asp to BALB/c mice. The obtained antibody has a high specificity toward d-Asp but shows a slight cross-reactivity to all other d- and l- amino acids including l-Asp. The calibration range of the competitive enzyme linked immunosorbent assay (ELISA) is 0.016-16 μmol/mL d-Asp in rat serum samples. The precisions of this method were evaluated by inter-plate and intraplate assays, and the relative standard deviation values were 4.8% and 4.5%, respectively. The values of d-Asp determined by the present ELISA have a good correlation to those determined by high-performance liquid chromatography with the correlation coefficient of 0.963. Using this ELISA, the time course of d-Asp in the rat serum after intravenous administration was successfully demonstrated. The present method provides a simple and high-throughput determination of d-Asp in mammals, and is a useful tool for clarifying the physiological roles and diagnostic values of this d-amino acid.     

Modulation of plumbagin production in Plumbago zeylanica using a single-chain variable fragment antibody against plumbagin

A single-chain variable fragment antibody (scFv) against plumbagin (PL) accumulated the PL production in the hairy roots of Plumbago zeylanica. Recombinant Agrobacterium rhizogenes (ATCC 15834) containing an scFv gene against PL (PL-scFv) were obtained through triparental mating and transformed into P. zeylanica to induce PL-scFv protein in the hairy roots. Up to 40 μg recombinant PL-scFv were expressed per milligram of soluble protein in transgenic P. zeylanica hairy root cultures. The mean PL content obtained from transgenic hairy roots (12.24 μg/100 mg dry weight) exhibited 2.2 times higher than those obtained from wild-type (5.48 μg/100 mg dry weight). The high correlation between the PL-scFv expression level and PL content of the recombinant plants suggested that the PL biosynthesis pathway had been modulated by the expression of PL-scFv protein in the hairy roots of P. zeylanica.     

Reforestation of abandoned pasture on Hokkaido, northern Japan: effect of plantations on the recovery of conifer-broadleaved mixed forest

When pasture land is abandoned, there are, in many cases, inhibitory factors that slow the rate of transition to a natural vegetation. Accordingly, the planned management of restoration has become an important issue in various parts of the world, where environmental conditions can vary widely. Although tree plantations are widely used as a management tool for restoration, there have been few studies addressing the practical aspects of the procedure. I examined effects of tree plantations within the framework of an evaluation of methods for restoring abandoned pasture on Hokkaido, northern Japan. I developed and analyzed vegetation maps spanning the past 57 years for the old-growth site influenced by artificial disturbance; the procedure revealed the pattern of change in the vegetation cover. Matrix model analysis showed that intensive use of plantations contributed to reduction of the area occupied by dwarf bamboo and pasture land (i.e., superior to simple abandonment). Furthermore, the field study of vegetation types and changes in species composition over 20 years suggests that plantations have contributed to a reduction in the effects of factors that inhibit revegetation. However, the establishment of monoculture plantations is frequently viewed skeptically as a procedure that is applied without fundamental ecological knowledge. For sustained management, adequate historical and ecological information on the restoration site should be provided to all stakeholders. An erratum to this article can be found at     

Production of glycyrrhizin in callus cultures of licorice

Licorice plants, Glycyrrhiza glabra, G. uralensis, and G. inflata, were investigated for callus induction using Murashige and Skoog (MS) medium combined with auxins and cytokinins. After 4 weeks of culture, 33-100% of leaf or stem explants formed calli. Maximum of shoot induction from callus cultures was achieved by G. inflata stem explants cultured on MS medium supplemented with 1 mg/l alpha-naphthaleneacetic acid (NAA) and 0.5 mg/l 6-benzyladenine (BA) (67%) which also gave maximum shoot formation per explant (two shoots per explant). These results indicated that all three Glycyrrhiza species regenerated shoots from callus cultures on MS medium combined with NAA and BA or only thidiazuron (TDZ; 0.1 and 0.5 mg/l). Glycyrrhizin contents of G. uralensis calli induced using MS medium in combination with NAA and BA [(27.60 +/- 8.47) microg/g DW] or TDZ alone [(36.52 +/- 2.45) microg/ g DW] were higher than those found in other combinations.