The advances in molecular genetics and biotechnology in the field of medicinal plant research are discussed with focusing on the works using transgenic plants. Differentiated organ cultures and transgenic teratomas, incited by the infection with mutants of Agrobacterium Ti and Ri plasmids, were established in quinolizidine-alkaloid producing plants and Solanaceae plants. These cultured cells were used for the production and bioconversion of specific alkaloids produced in these plants. The methods of integration of foreign genes into medicinal plants were developed using an Ri binary vector. The mode of gene expression driven by TR1'-2' promoters was elucidated in transgenic medicinal plants, e.g., Nicotiana tabacum, Glycyrrhiza uralensis, Digitalis purpurea and Atropa belladonna. The genes for herbicide resistance, mammalian cytochrome P450 and bacterial β-hydroxydecanoylthioester dehydrase were transferred and expressed in plants either to confer herbicide-resistant trait or to change the pattern of metabolites. The cDNA clones encoding cysteine synthase responsible for sulfur assimilation and biosynthesis of non-protein amino acids were isolated and characterized from Spinacea oleracea and Citrullus vulgaris. The functional lysine residue was identified by site-directed mutagenesis experiments. An over-expression system in Escherichia coli was constructed for the bacterial production of the plant specific non-protein amino acids. We made transgenic N. tabacum integrated with sense- and antisense-constructs of cysteine synthase cDNA driven by cauliflower mosaic virus 35S promoter for the purpose of genetic manipulation of biosynthetic flow of cysteine in plants. The future prospects of medicinal plant research are also discussed in the context of modern plant molecular biology.
Procaine hydrochlorate is identified by the melting point of Procaine picrate (JP XII). Although the melting points of monopicrate (1) and dipicrates (2) of procaine have been reported, they are inconsistent each other in their reports. It is not specified 1 or 2 in JP XII. From these reasons, the crystal structures of 1 and 2 of procaine have been elucidated by X-ray crystallographic analysis and each melting point is clarified. 1 is formed through the hydrogen bond between the phenolic hydroxyl group of a picric acid molecule and the tertiary amine of a procaine molecule, and the melting point of 1 was 133-135°C (decomp.). 2 is formed through the hydrogen bonds between the tertiary and the first amines of a procaine molecule and the phenolic hydroxyl groups of two picric acid molecules, respectively. The melting point of 2 was 152-155°C (decomp.).
A new chemotype of Microlepia marginata, P-type strain, was found in the Central districts of Japan. The two main constituents were characterized to be 2β, 15 (R), 16-trihydroxy-ent-pimar-7-en-3-one (fumotoshidin A) and 3α-α-L-arabinofuranosyloxy-15 (R), 16-dihydroxy-ent-pimar-7-ene (fumotoshidin arabinoside). The young fronds of this strain have reddish stipes, which is a common feature to Y-type strains also containing ent-pimarane-type glycosides.
A simple and precise method was established for the determination of synephrine in oriental pharmaceutical decoctions containing Evodiae Fructus using high-performance liquid chromatography with sodium dodecyl sulfate (SDS) as an ion-pair reagent. Synephrine was eluted within 25 min without interference from co-existing components using an ODS column and a mixture of water-acetonitrile-SDS-phosphoric acid (70 : 30 : 0.5 : 0.1, v/v/w/v) as a mobile phase.
A Cl--intercalated hydrotalcite-like compound (HTAL) is a promising material as a better phosphate adsorbent for further clinical use than the currently marketed aluminum hydroxide gels. In the preceding study, we found that Cl- ions in the interlayer of HTAL can be exchanged with phosphate ions equivalently. In the present study, we have investigated the adsorption of porcine pancreas trypsin on HTAL and the influence of trypsin adsorption on the phosphate/Cl- ion-exchange properties of HTAL. The isotherm for trypsin adsorption at 310 K and pH 8.4 showed the curve of BDDT V type and gave an adsorption capacity of 88.6 mg/g for trypsin. The zeta-potential analysis of HTAL suggested that the trypsin adsorption on HTAL at pH 8.4 was restrained by the electrostatic repulsion between HTAL surface and trypsin with positive charge. XRD and nitrogen adsorption studies showed that trypsin was adsorbed on the external surface of HTAL by occupying the area (ca. 22 nm2) per trypsin molecule. The phosphate/Cl- ion-exchange reaction with HTAL was not affected by the presence of trypsin ; the phosphate ion-exchange capacity reached 73.6 mg P/g from the solution containing 3200 mg trypsin/dm3. On the other hand, the trypsin adsorption was significantly depressed by the loading of phosphate ions. The XRD analysis of the phosphate-loaded HTAL revealed that the layered structure of hydrotalcite holds after the phosphate ion-exchange, but shows a slight increase of the interlayer distance from 0.3 nm to 0.5 nm by the intercalation of phosphate ions.
Aqueous solution of oxo [5, 10, 15, 20-tetra (4-pyridyl) porphyrinato] titanium (IV) complex, a Ti-TPyP reagent, was found to be very useful for the spectrophotometric determination of hydrogen peroxide. The reagent (λmax 432 nm) reacts with hydrogen peroxide to form a monoperoxocomplex, resulting in a significant decrease of the absorbance at 432 nm. The decrease (ΔA) in absorbance was proportional to the concentration of hydrogen peroxide. The Ti-TPyP reagent was successfully applied to the assay of uric acid in the serum, using uricase to produce hydrogen peroxide through enzymatic oxidation. Using only 5 μl serum, a linear relationship was obtained between ΔA and uric acid concentration in the serum ranging from 5×10-6 to 1×10-3 M. The apparent molar ΔA of uric acid was 2.2×105 M-1 cm-1. The relative standard deviation of repeated runs (n=8) was 2.8% at 3.77×10-4 M uric acid. The analytical recovery of uric acid (5×10-4M) added to the serum was 96.8 to 105.0%. No pre-concentration and deproteinization were required to determine uric acid in the serum by the present method because of the high sensitivity and selectivity of the Ti-TPyP reagent for hydrogen peroxide.
The N-alkylcarboxylic acids of 1, 2, 3, 4, 10, 14b-hexahydrodibenzo [c, f] pyrazino [1, 2-α] azepine (6a) and 2, 3, 4, 9-tetrahydro-1H-dibenzo [3, 4 : 6, 7] cyclohepta [1, 2-c] pyridine (6b) were synthesized and examined for pharmacological activities in vitro : an inhibitory effect on the monoamine [noradrenaline (NA) and 5-hydroxytryptamine (5-HT)] uptake into the rat crude synaptosome, an inhibitory effect on the 5-HT- and NA-induced contraction in the isolated rabbit aorta and on the histamine- and acetylcholine-induced contraction in the isolated guinea-pig ileum, and binding affinity for α2-adrenoceptor and D2-receptor. The in vitro tests indicated that zwitter-ionization was capable of maintaining antihistaminic activity while greatly reducing other pharmacological activities such as effects on central nervous system. 3-[2, 3, 4, 9-Tetrahydro-1H-dibenzo [3, 4 : 6, 7] cyclohepta [1, 2-c] pyridin-2-yl] propionic acid (6b-2), selected as a candidate antiallergic agent having equally potent activities in rats and guinea-pigs, exhibited strong inhibitory effects on 48 h homologous passive cutaneous anaphylaxis (PCA) in rats (ED50=0.012 mg/kg, p.o.) and on histamine-induced bronchoconstriction in anesthetized guinea-pigs (ED50=0.0088 mg/kg, p.o.).