The external magnetic field effects on photochemical, thermal, and electrochemical reactions were investigated with the aid of time-resolved laser spectroscopic techniques and so on. Significant magnetic field effects were observed for the primary reaction steps as well as the product yields of photoinduced hydrogen abstraction and electron transfer reactions of aromatic molecules in aqueous micellar solution. Analogous effects were observed for the photoreactions of bifunctional chain molecules. These effects can be interpreted in terms of the radical pair model. The effects on electrochemical reactions can be interpreted in terms of the magnetohydrodynamics mechanism.
Development of several highly selective and effective reactions or synthetic strategies and their application to the synthesis of complex, bioactive natural products are described. Particular attention was focussed on the role of new methodologies in constructing complex target molecules.
Some analogues of glycyrrhizin were synthesized by coupling of methyl glycyrrhetate with per-O-acetylated glycosyl bromides of mono- and disaccharides by means of Koenigs-Knorr type condensation followed by deprotection. Sophorosyl and 6, 6'-dideoxysophorosyl analogues were synthesized through stepwise glycosylation. The anomeric configuration of newly formed sugar-aglycone linkages of these glycosides (4a-p, and 7) were determined as β on the basis of 1H- and 18C-nuclear magnetic resonance spectral data.
Factors which affect the content of flavonoids in Kijitsu were studied. Flavonoids in immature citrus fruit decomposed gradually by standing after divided horizontally in two parts. About 90% of flavonoids were retained by use of hot air drying of fresh samples. The content of flavonoids in Kijitsu decreased to about 60% by standing one year. Flavonoid contents decreased corresponding with an increase in diameter of Kijitsu. There is no wide difference between Hassaku and other Citrus fruits in their essential oils determined by gaschromatography-mass spectrometry. It was concluded that C. hassaku might be used for the material for Kijitsu.
3, 5-Diacetyl-1, 4-dihydro-2, 6-dimethylpyridine (DDL), prepared by the condensation of 1 mol of formaldehyde with 2 mol of acetylacetone in the presence of ammonia and applied to a colorimetric determination of formaldehyde, was studied by polarography. It was found that the direct current and square wave polarograms and the cyclic voltammograms of DDL at pH 2 and 10 showed irreversible reduction waves. DDL was easily oxidized to colorless 3, 5-diacetyl-2, 6-dimethylpyridine in acidic solutions by exposure to daylight and air, but stable in basic solutions. Thus, DDL solution should be made to be basic by adding tetraethylammonium hydroxide immediately after the reaction of formaldehyde with acetylacetone in the presence of ammonium acetate. Formaldehyde can be easily determined by the polarography of the alkaline DDL solution.
Enantiomeric separation of Azerastine hydrochloride, antiallergic drug, was developped by high-performance liquid chromatography. Optical resolution was investigated by ion pair chromatography using d-10-camphorsulfonic acid as a chiral counter ion and a polar stationary phase, Nucleosil 5CN. The increase of the chiral counter ion decreases retention of Azerastine. Good separation was obtained at 0°C of column temperature. By the use of 1-10-camphorsulfonic acid, elution order of enantiomers was reversed. The precision of the method was tested by performing replicate assay.
It was found that a plasmid which had a foreign deoxyribonucleic acid (DNA) between two repeated sequences did not multiply in E. coli recBCsbcB, even if it multiplied in wild-type E. coli, E. coli recBC or E. coli recBCsbcBrecF when the insert was longer than 351 base pair. The multiplication of these plasmids were, however, inhibited when a plasmid expressing recF gene was introduced into E. coli recBCsbcBrecF. The inviability of the plasmid carrying the repeated sequence in E. coli recBCsbcB was discussed by the mechanism of recombination, and the functions of recF, recBC and sbcB were speculated. When E. coli recBC was transformed with pDR1 which was a derivative of pBR322 carring a directly repeated sequence between which a DNA fragment derived from plasmid R6K with its origin was inserted, the intramolecular recombinant appeared. The recombinant recovered was, however, only the plasmid which had the replication origin of pBR322. The result suggests that pBR322 is compatible with pDR1 but R6K is not. The replication origin of R6K seems to be preferrentially used by pDR1.
The crude extract (fraction II) prepared from E. coli could replicate plasmid pKYM, only when the extract contained the rep protein which was produced by the plasmid and essential for its multiplication in vivo. The intermediate of replication was accumulated when a dideoxynucleotide triphosphate was added to the reaction mixture. By analyzing the intermediate, the initiation site of the deoxyribonucleic acid replication and the direction of replication could be determined. The replication initiated inside the ori region of pKYM and the direction was unidirectional. The analysis also suggested that the synthesis of the lagging strand stopped at almost the same site as the initiation site.
Anti-ulcerogenic activities of a 50% ethanolic extract ([M]) from whole body of Agkistrodon blomhoffii blomhoffii BOIE were investigated in rats. [M] at oral doses of 250-500 mg/kg was found to show a prophylactic effect on the water-immersion stress-and ethanol-induced ulcer and a remedial effect on acetic acid-induced ulcer, but not Shay-ulcer in pylorus-ligated rats and indomethacin-induced ulcer. [M] increased the gastric mucosal blood flow in intact rats and improved the decrease of the blood flow in acetic acid-induced ulcer rats. [M] inhibited the decrease in content of hexosamine of gastric mucosa in rats treated with acetic acid. These results suggest that [M] have a prophylactic effect on ulcerogenics, and an anti-ulcer effect by the increase and/or maintenance of gastric mucosal blood flow and hexosamine, but further investigations are required to understand the mechanism involved.
The pharmacological actions such as analgesic effect, diuretic action, hypoglycemic activity and hypotensive action were studied on the methanol extract of the Japanese mistletoe and the European mistletoe. The both extracts showed the hypotensive action when administered intravenously to cat. The methanol extract of the Japanese mistletoe also showed a increase of K+ value in the urine when administered orally to rat.
Anthracene-1-carbonyl azide was found to be a sensitive fluorescent derivatization reagent for primary and secondary alcohols for high-performance liquid chromatography. Reaction conditions were investigated for cholestanol. The reagent reacts with alcohols in benzene in the presence of 4-dimethylaminopyridine to give the corresponding fluorescent urethanes at 100°C for 50 min. The detection limit for cholestanol was 250 fmol for an injection volume of 10 μl. Tertiary alcohols and phenols do not produce fluorescent derivatives under these conditions.