This review involves the recent progress of "The Chemistry of Benzo [c] phenanthridine Alkaloids" developed in our laboratory. Structural establishment of naturally occurring four new amides, arnottianamide, isoarnottianamide, integriamide, and iwamide, was performed by deriving from chelerythrine, nitidine, avicine, and decarine, respectively, by using the Baeyer-Villiger type oxidation of an immonium group, developed in our group. The fully aromatized O5-benzo [c] phenanthridine alkaloids, chelirubine, chelilutine, sanguilutine, and sanguirubine, were synthesized by photo-cyclization of an enamide or by the revised Robinson method. In general, this revised method is also applicable to the synthesis of the 8, 9-oxygenated O4-bases, for example nitidine was prepared by this method in 40% total yield. The induced shift of 1H-NMR signals of oxybases is discussed.
An automatic recording system was developed for the dynamic measurement of the unfrozen water content and the spin-spin relaxation time as a continuous function of temperature. The system consists of a broad-line pulsed NMR spectrometer, a wave form memory apparatus, and a minicomputer, by using the special thermocouple shielded from electric noise by aluminum metal and coated with thermal insulater. The freezing and thawing processes were measured for aqueous solutions of saccharides and sugar alcohols, and the mobilities of solute and hydrated water molecules in frozen solutions were investigated. It was shown that sugar alcohol and mono- and oligosaccharide molecules are clustered by freezing of free and loosely-bound water and solidified in low temperature regions together with tightly-bound water. Mannitol is unusual amongst carbohydrates because that it crystallizes out in the thawing process, at about -22°C, and the freeze-drying of its aqueous solution is very easy. Hence mannitol is the most suitable dilient of drugs for freeze-drying use. But at the colling rate of one degree per minute or more slowly, it crystallizes out in the freezing process, and by freeze-drying powder which is unpractical in appearance and solubility with many spherulite crystals of about 1 mmφ was given. The advantages of the above method, namely the freezing curve method in pharmaceutical sciences were emphasized.
Inhibitory effects of tannins on copper (II)-catalyzed autoxidation of ascorbic acid were examined. Tannic acid JP and geraniin were shown to be much more effective than the related polyphenols of smaller molecules, gallic acid and pyrogallol etc. Geraniin showed a stronger antioxidative effect than tannic acid JP. This result is attributable to the possible chelation between the potential triketone moiety in geraniin, and the metal ion. The quantitative analysis of ascorbic acid in the reaction mixture was carried out by dual-wavelength thin-layer chromatography-densitometry which gave reproducible results in the presence of polyphenols.
By the screening for passive cutaneous anaphylaxis and haemagglutination anaphylaxis, ethyl α-D-fructofuranoside was isolated from EtOH extract of Zizyphi Fructus. Ethyl α-D-fructofuranoside, an artifact, indicates a possible use as an anti-allergic agent.
Conventionally, in gel permeation chromatography (GPC) it has been almost impossible to separate and identify proteins having near molecular weight. As for high performance liquid chromatography (HPLC) method, which has been developed in our previous report, it was examined whether it can be applied to simultaneous, efficient separation and identification of six kinds of proteins having molecular weight of 21000-26000 ; trypsin inhibitor (soy beans), trypsin, trypsinogen, α-chymotrypsin, α-chymotrypsinogen and elastase. Under isocratic elution system by using Nucleosil CN as a stationary phase and sodium ethanesulfonate, sodium pentanesulfonate or octanesulfonate as an ion-pair reagent in mobile phase, all of them could be satisfactorily chromatographed.
The structures of polysaccharides obtained from hot water extract of Mycobacterium tuberculosis strain Aoyama B were investigated. The polysaccharides fractionated by moleculer sieve-, ion exchange- and affinity-chromatographies and ethanol precipitation were analysed. Main polysaccharides clarified from the results are ; 1) arabinomannan in which arabinan core and mannan core coupled alternately, having average molecular weight of about 12000, 2) mannan with many side chains and average molecular weight of about 5000, 3) a mixture of lipoarabinomannan and lipomannan with fatty acid ester of about 18%, 4) acidic lipoglucan consisting of 6-O-methyl-D-glucose, glucose, 3-O-methyl-D-glucose, glyceric acid, and 6-9 moles of lower fatty acid esters, 5) glycogen-like highmolecular glucan, 6) low-molecular mannan and glucan.
Ground mixtures containing 2-oxo-3-[4-(1-oxo-2-isoindolinyl) phenyl] butanamide (OIB) were prepared from synthetic high molecular compounds, celluloses, sugars, peptides and amino acids in order to improve dissolution and absorption characteristics of OIB, and the physicochemical properties and the gastrointestinal absorption of these various ground mixtures were compared. Endothermic heat due to the fusion of OIB on differential scanning calorimetry disappeared in some of the ground mixtures of OIB-additives (1 : 9), and X-ray diffraction of the ground mixture indicated that OIB was an amorphous form. The dissolution rates of all of the ground mixtures were found to be faster than that of OIB alone, but differences in dissolution rates were observed by the kind of additive. The ground mixtures with peptides, such as gelatin (GEL) and lysozyme, showed the highest dissolution rate. The absorption of OIB alone and of four ground mixtures containing GEL, polyvinylpyrrolidone, methyl cellulose and microcrystalline cellulose were investigated in dogs. The serum concentration of OIB was enhanced more markedly than that of drug alone, and especially, the ground mixture with GEL increased 15-fold with respect to the amount of OIB absorbed.
The ground mixtures of several poorly water soluble drugs such as diphenylhydantoin (DPH) and soluble proteins such as gelatin, were prepared in order to improve dissolution properties and gastrointestinal absorption of the drugs. The drugs in the ground mixtures were found to be an amorphous form by the differential scanning calorimetry (DSC) and the X-ray diffraction measurement. The dissolution rates of the ground mixtures of poorly water soluble drugs and soluble proteins increased more markedly than the drugs alone and were greater than those of the ground mixtures of the drugs and microcrystalline cellulose (MCC). The ground mixture of DPH and gelatin (A), DPH alone (B) and the ground mixture of DPH and MCC (C) were administered in the dogs, and the DPH concentration in the serum were measured. As the result, the area under the serum concentration-time curve of A was 5.3, 1.7 times greater than those of B and C, respectively.
The dissolution behavior and bioavailability in man of 1 : 1 sulfamethoxazole-trimethoprim complex (STC) and its physical mixture (STM) were compared. The mean particle size of both drug powders used in this study was less than 10 μm. In the pH range of gastrointestine, no difference in solubility between STC and STM was substantially detected and the stability constant of STC in its dissolved form was less than about 19 M-1. Furthermore STC and STM exhibited an equal dissolution rate in the pH range of less than 3, while STC showed a lower dissolution rate than STM in pH 4.5-7.5. On the other hand, no difference was found between STC and STM in fine granules as to the rate and extent of bioavailability in man. These findings lead to a conclusion that the dissolution processes of both drug powders are not rate-limiting in absorption because these particle sizes are fine enough. STC did not have a bitter taste due to trimethoprim : this may be interpreted by the fact that the concentration of trimethoprim during dissolution process of STC in a salivary pH did not reach the threshold concentration for a bitter taste. The above results showed that STC has a great advantage in formulation of the oral preparations with no bitter taste bioequivalent to STM-containing oral preparations.
Germanium dioxide and 4 molar equivalents of L-cysteine were heated in water to give a crystalline compound which was assigned to tetrakis (2-amino-2-carboxyethylmercapto) germane on the basis of microanalytical and spectroscopic data.
A sensitive and selective gas chromatographic method for the determination of glycerophosphate was carried out and good results were obtained, in which a flame photometric detector (FPD) was used as a detector and the emission was measured with a photomultiplier tube through an interference filter with a transmission maximum at 526 nm. Glycerophosphate was trimethylsilylated with bis (trimethylsilyl) fluoroacetamide containing 1% trimethychlorosilane in pyridine. Tetrakis (trimethylsilyl)-glycerophosphate was subjected to a gas chromatograph equipped with an FPD and a glass column (3 mm i.d.×1 m) packed with 2% OV-17 on Chromosorb W, AW-DMCS. The column temperature was 160°C, the carrier gas was nitrogen at a flow-rate of 40 ml/min, the fuel gas was hydrogen (100 ml/min) and oxygen (20 ml/min), and detector gas was nitrogen (40 ml/min). The photomultiplier voltage was 700 V. Response to glycerophosphate was found to be linear from 1 ng to 1 μg. The retention times of glycerophosphates of GC-FPD were as follows : β-glycerophosphate (3.2 min), α-glycerophosphate (3.8 min). This method was found to be much more rapid and simple than a paper chromatography and a thin-layer chromatography. Thus the method is convenient for the measurement of glycerophosphates in commercial phospholipids.