The esterase-like active sites of human serum albumin (HSA) are closely related to its drug binding sites. The enzymatic activities towards p-nitrophenyl acetate (NPA) and nitroaspirins are inhibited by the presence of various drugs. From the inhibition patterns drugs can be classified according to their binding site, and this classification corresponds well to those obtained by other conventional methods (Table V). The inhibition of enzymatic activities was quantitatively studied and theinhibition schemes presented were well verified by using analog computer analysis. The drug binding parameters were also determined from kinetic data, which fairly correspond to those obtained by equilibrium dialysis. The enzymatic active site towards NPA (named as R-site) was found to be locatednear Tyr-411, which was concluded from the quantitative decrease in enzymatic activity due to DFP modification of this amino acid residue. The e izymatic active site towards nitroaspirins (named as U-site) was found to be located near Lys-199, which can be concluded from the decrease in the activitydue to the acetylatioa of this amino acid residue with aspirin. U-site seems to be located also closely near to Trp-214, which can be confirmed by the quenching of fluorescence of this single amino acid in the presence of the substrates and the drugs bound to this site. The enzymatic activities of HSA towards other 6 substrates including amides and organic phosphate were studied.
Plant tissue culture is profitably used in biotechnology today to produce valuable compounds and to rapidly and uniformly propagate economically important plants. The main objective of this review is to outline the advances in the production of medicaments and biochemicals by plant tissue cultures. In relation to this objective, the development of newly advanced techniques such as transformation, cell fusion, biotransformation, bioreactor with immobilized plant cells, and synthetic seeds, is briefly discussed. Recent studies in my laboratory on the bioconversion of 2-phenylpropionic acid (mainly glycosylation) and l-menthol (glycosylation and hydroxylation) by plant suspension cells, and of codeinone (reduction) by the bioreactor with immobilized opium poppy cells, and on the de novo synthesis of stress metabolites in the immobilized licorice cells, are described. The production of Korean ginseng and saponin ginsenosides in Korean ginseng suspension cells, and of Vitamin E in safflower cells are also discussed.
The molecular structures of p-nitro and p-chlorobenzyl derivatives of barbital were established as 5, 5-diethyl-1, 3-bis (p-nitrobenzyl) barbituric acid (1) and 1, 3-bis (p-chlorobenzyl)-5, 5-diethylbarbituric acid (2) by means of the X-ray crystallographic analysis. Both crystals belong to a monoclinic system with a space group P211/n. The cell constants for 1 are a=14.650 (1), b=16.009 (1), c=9.549 (1)Å, β=97.70 (1)°, and those of 2 are a=18.027 (4), b=8.374 (1), c=15.271 (3)Å, β=106.92 (2)°. The structure of 1 was refined to be R=0.099 for 1802 reflections, and that of 2 to be R=0.088 for 2969 reflections.
The following results were obtained during synthetic studies of 4-and 5-nitro derivatives (7 and 8) of N-(2-nitroxyethyl) nicotinamide, a new antianginal drug (I). 1) Nicotinic acid 1-oxide (1a) and its derivatives (1b, c, d) resisted γ-nitration, whereas the methyl ester (1b) underwent β-nitration on treatment with N-nitropyridinium tetrafluoroborate at room temperature in dichloromethane. 2) 4-Nitronicotinic acid 1-oxide (2a) was successfully converted to the methyl ester (2b) and the amide (2c) in good yields by treatment with diazomethane and through the active ester with 1-hydroxybenzotriazole, respectively. 3) Deoxygenation of 2b and 2c was smoothly effbcted with phosphoryl bromide, but that of 2a gave no 4-nitronicotinic acid. 4) On the basis of these findings, 7 and 8 were synthesized starting from 2a through the amide 2f, and from 5-nitronicotinic acid, respectively.
Corni Fructus (shanzhuyu), one of the important crude drugs in the traditional Chinese medicine, was said to be the sarcocarp of Cornus officinalis SIEB. et ZUCC. from which the seed has been removed. Internal morphologies of the crude drug were observed by comparison with some developmental stages from the flower bud to the mature fruit. The result of the observation made it clear that this crude drug was matured tissue of hypanthium, and that the removed part was the true fruit whose pericarp had been transformed into stone cells. Corni Fructus (shanzhuyu), one of the important crude drugs in the traditional Chinese medicine, was said to be the sarcocarp of Cornus officinalis SIEB. et ZUCC. from which the seed has been removed. Internal morphologies of the crude drug were observed by comparison with some developmental stages from the flower bud to the mature fruit. The result of the observation made it clear that this crude drug was matured tissue of hypanthium, and that the removed part was the true fruit whose pericarp had been transformed into stone cells.
In the course of screening of natural products for Ca2+-blocking activity in rat thoracicaorta, Magnoliae Cortex, a Chinese harbal medicine, was found to possess such activity. Its active principles were identified as magnolol and honokiol. Both magnolol and honokiol showed inhibitory effects, similarly to that of verapamil, on contractile response to high concentration of potassium ion, Ca2+, norepinephrine in Ca2+-free medium and 45Ca2+-uptake, and two orders of magnitude less active than velapamil.
The active principles of Artemisia montana and A. princeps as “tannin” of these species were isolated and identified as 3, 5-, 3, 4- and 4, 5-di-O-caffeoylquinic acids. The results of relative astringency based on geraniin (RAG) and relative affinity to methylene blue based on geraniin (RMBG) value determination, quantitation of these compounds by high performance liquid chromatography and two-dimensional thin layer chromatography showed that the activity of the extracts of these species are mainly due to these components. Although a comparatively small amount of chlorogenic acid was also isolated, the low values of RAG and RMBG indicate that it is almost indifferent to the activity as “tannin” of these species. Fairly abundant presence of these caffeetannins was also found in the hair (moxa) on the leaf of A. montana. The distribution of these caffeetannins in the other species of Artemisia and in the species of several Genera in Compositae, showed that the species which have been used as hemostatics generally contain caffeetannin of composition similarly to those of A. montana and A. princeps and markedly different from that in coffee.
A method for the microdetermination of dihydroergotoxine (DHETX) levels in the human plasma by gas chromatography/high resolution-selected ion monitoring (GC/HRSIM)(M/ΔM=5000) has been investigated to study the pharmacokinetics of DHETX in man. Deuterium labelled dihydroergotamine was prepared by catalytic hydrogenation of ergotamine by deuterium gas and used as an internal standard for quantification.To the plasma was added [2H3] dihydroergotamine followed by extraction of DHETX by using ClinElut ®, and DHETX was hydrolysed to dihydrolysergic acid. Dihydrolysergic acid was analysed as its N-trimethylsilyl ethyl ester using the molecular ions with m/z 370.2076 and 373.2265. Thus, GC/HR-SIM made it possible to quantify selectively trace amounts of DHETX in the human plasma without interference of endogenous substances and/or silylating agent. Detection limit was 2 pg with S/N of 19, better than that of conventional GC/LR-SIM. Improvement of sensitivity in high resolution-mode may be attributable to enhancement of the S/N ratio in the detection of SIM.
Naphtidrofuryl oxalate (LS121), which is a peripheral blood vessel dilator, was intravenously infused to volunteers. The time courses of the blood concentration of naphtidrofuryl (LS84) and its three metabolites were determined to calculate pharmacokinetic parameters. The data were well simulated by the linear compartment model with two compartments for LS121 and one compartment for the metabolite. The dose of the LS121 increased from 120 mg to 200 mg, but the parameters estimated did not change, indicating the absence of the saturation of the metabolism. In case of the multiple intravenous infusion for 2 h every day for 7 d, the observed time courses of the blood concentration of all the four compounds were well simulated by the parameters calculated by the data of the first day. The conclusion was that the pharmacokinetic parameters did not change after the multiple dosing.
Naphtidrofuryl oxalate (LS121) was orally administered to volunteers in the fasted or non-fasted state and the time courses of the serum concentration of naphtidrofuryl (LS84) and its three metabolites were determined. In case of the non-fasted state, the maximum serum concentration (Cmax) decreased and the time when the Cmax appeared (Tmax) delayed compared to the fasted state, in all the four compounds. The area under concentration time curve calculated by the trapezoidal method using the observed data (AUCobs or AUCobs, m) increased in the non-fasted state. The bioavailability of LS84 estimated by the AUCobs devided by the calculated AUC (AUCcal) from the pharmacokinetic parameters in the intravenous infusion experiments which were reported in the preceding paper, were 23.0% in the non-fasted state and 20.2% in the fasted state. The AUCobs, m of three metabolites were larger than AUCcal, m calculated from the AUCobs of LS84 according to the intravenous infusion results reported in the preceeding paper. The percentages of the AUC of the first-pass effect were calculated by the equation that (AUCobs, m-AUCcal, m)/AUCobs, m, and were about 80% for three metabolites. It was concluded that about 20% of the oral dose removed unchanged to the circulation system and the rest 80% was metabolized by the first-pass effect.
The effect of aluminum ion on the gastrointestinal absorption of sulfisomidine was examined in rabbits. Aluminum ion significantly reduced the maximum blood concentration (Cmax) of sulfisomidine after oral administration. Aluminum ion also prolonged the time taken to reach the maximum blood concentration (Tmax) and the mean absorption time (MAT) of sulfisomidine. In addition, aluminum ion was found to delay gastric emptying in rabbits. On the other hand, aluminum ion had no effect on the area under the blood corlcentration-time curve (AUC0∞) or the pharmacokinetic parameters related to distribution and elimination of sulfisomidine. These results indicate that aluminum ion causes a decrease in the absorption rate of sulfisomidine, by delaying the gastric emptying.
The power consumption in a kneading mixer (granulator) is measured under various conditions. It is proved from the point of visual inspection, spheroidicity, apparent density and yield of granules that the process of agitating granulation can be estimated by power consumption change with time. Regardless of the presence of binder or the type (powder or liquid), end-point of granulation at which an excellent yield of spherical and well-compacted granules is obtained, is almost correspond to the point which the power consumption reaches a steady state (early phase of zone IV). The times required to reach the steady state power consumption after the completion of adding the binder are almost constant, regardless of the adding time, while the long time results in a wider granule size distribution and reduction of the yield of granule. It is suggested that 50% mean granule diameter and the yield of granules can be estimated by measurement of power consumption. Furthermore, physical properties, the yield and granulating time of granules produced by using the binder in the state of powder, which is convenient for handling in comparison of liquid, are similar to the use of liquid binder.
The chemical constituents of the methanol extracts of dried whole parts of Lysimachia japonica THUNB. and L. clethroides DUBY (Primulaceae) were studied. Salicylic acid and flavonol glycosides, hyperin, rutin and kaempferol-3-O-rutinoside were isolated from the former and four flavonol glycosides, astragalin, isoquercitrin, kaempferol-3-O-rutinoside and kaempferol-3-O-(2, 6-di-O-rhamnopyranosylglucopyranoside) were isolated from the latter. Salicylic acid and kaempferol-3-O-(2, 6-di-O-rhamnopyranosylglucopyranoside) were first isolated from Lysimachia plants.
Spectrophotometric determination of sodium bisulfite in parenteral admixture was attempted by use of spectral changes due to complexation with pyridoxal phosphate. By applying complementary tristimulus method with consideration of the stability constant, the exact concentration of each chemical species in the solution could be estimated accurately. When this method was applied to Primperan ® injection, the sodium bisulfite content could be determined rapidly. The coefficient of variation (n=3) in this determination was 1.92%.
The effect of Zingiberaceae crude drug extracts on the small intestinal absorption of sulfaguanidine was investigated in the rat by the in situ recirculating perfusing method. extracts of Zingiberaceae crude drugs such as Alpiniae officinarum Rhizoma, Alpiniae oxyphyllae Fructus, Zingiberis Rhizoma, Curucumae Rhizoma, Amomi Semen, Amomi rotundi Fructus, Cardamomi Fructus Zeodriae Rhizoma (from China and Yaku-shima), were prepared by use of H2O and/or MeOH. The absorption of sulfaguanidine was affected in various ways by these extracts.The H2O extract of Alpiniae officinarum Rhizoma enhanced the absorption of sulfaguanidine most effectively. This extract was more effective than sodium deoxycholate which increased sulfaguanidine absorption from the rat small intestine. These results showed that Zingiberaceae crude drugs might affect the small intestinal absorption of any other drugs.