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At least 1,063 records · Page 59Linked to original sources
PubMed1991

[Determination of myristicin and safrol in the volatile oil of semen Myristicae and its processed products by TLC-scanning].

This paper reports the determination of myristicin and safrol in the volatile oil of Semen Myristicae and its processed products by TLC-Scanning. The results showed that in the processed products myristicin decreased markedly and safrol decreased slightly. The quantity of myristicin roasted with paste less than with wheat bran less than with talcum powder less than the unprocessed one. The toxicity of Semen Myristicae is related to the quantities of myristicin.

Allylbenzene Derivatives↗
PubMed1991

[Toxicologic investigations of selected phenolic compounds. I. Acute and subacute toxicity of guaiacol, methyl-guaiacol and syringol].

The aim of the investigations were determination of acute (A-DL50) and subacute (C-DL50) toxicity of guaiacol, methyl-guaiacol and syringol. White Wistar male rats, body weight 250 g +/- 20, were used. From the data obtained it was concluded that tested compounds could be classified to the fourth toxicity class (Hodge-Sterner classification). Cumulation coefficients show that no cumulation of there compounds occurs in a rat organism.

Animals↗
PubMed1990

[Effects of processing on volatile oil constituents in nutmeg and on the contents of myristicin].

This paper reports a GC analysis of the volatile oil contained in the nutmeg (Semen Myristicae) prepared by simmering wrapped in flour in hot purified talc, scalding in hot purified talc and stir-frying in smoking wheat bran. The experimental results showed that before and after processing the volatile oil compounds in nutmeg are the same and during processing no known compounds disappeared. The contents of the main volatile oil compounds in nutmeg changed, however, before and after processing, including the amounts of myristicin, one of the toxic compounds in nutmeg. It is suggested that the amounts of myristicin could be decreased notably under certain processing conditions.

Allylbenzene Derivatives↗
PubMed1990

[Effects of processing methods on the amounts of volatile oil of nutmeg and on isolation and characterization of the volatile oil constituents].

In this paper, the authors investigated the effects of various processing methods, i.e., scalding in hot purified talc, simmering wrapped in flour in hot purified talc and stir-frying in smoking wheat bran, on nutmeg (Semen Myristicae) in terms of the quantities of the volatile oil. The experimental results revealed that the amounts of volatile oil contained in nutmeg vary remarkably with the lengths of cooking time and the fluctuation of temperature. Detected by GC-MS-computer, 32 compounds of nutmeg were characterized, and their contents were determined by GC respectively.

Allylbenzene Derivatives↗
PubMed1989

Interactions between human extracellular superoxide dismutase C and sulfated polysaccharides.

The high heparin affinity subtype C of the secretory enzyme extracellular superoxide dismutase (EC-SOD) exists in the body mainly complexed with extracellular sulfated glycosaminoglycans (SGAGs). Addition of sulfated polysaccharides to EC-SOD C resulted in a prompt partial inhibition of the enzymic activity, in most cases amounting to 10-17%, but with the large dextran sulfate 500,000 amounting to 35%. Complex formation between heparin and EC-SOD C could also be observed as increases in apparent molecular weight of the enzyme. The findings suggest that the binding sites for SGAGs on EC-SOD C are localized far from the active site and that EC-SOD in vivo associated with SGAGs should retain the major part of its enzymic activity. Studies with amino acid-specific reagents suggested that both lysine and arginine residues are involved in the binding of SGAGs. In particular, modification of only a few lysine residues/subunit resulted in loss of high SGAG affinity, whereas arginine modification resulted in loss of not only SGAG affinity but also enzymic activity. We propose that this is due to modification of Arg-186, which is homologous to the highly conserved arginine in the entrance to the active site of the copperzinc-SODs.

Animals↗
PubMed1989

[Experimental methodology on pharmacological studies on crude drugs].

Properties of crude drugs are different from those of a pure synthetic compound which is prepared as a candidate for a newly developed drug in that; crude drugs are composed of innumerable ingredients and have at least some therapeutic efficacies. Accordingly, a pharmacological study of crude drugs resembles studying of a sample such as a complex combined preparation and a lot of problems upon pharmacological examination arises from properties inherent in crude drugs. In this review, these problems are discussed, being based on pharmacological studies which have been performed in several crude drugs.

Aconitine↗
PubMedDate not supplied

Investigation of some effects of levamisole on dog blood pressure.

The effects of levamisole were investigated on the blood pressure of anaesthetized dog. Levamisole (0.5 to 4.0 mg/kg) elicited a biphasic effect, an initial brief depressor response followed by a pressor response. The pressor response was dose-related and was blocked by phenoxybenzamine. The residual depressor response was blocked by propranolol. Repeated administration of a high dose of levamisole produced tachyphylaxis. The pressor response to levamisole was not modified by either reserpinization, acute bilateral adrenalectomy or pretreatment with cocaine, whereas pretreatment with dexamethasone, nialamide or pyroaallol shifted the dose-response curve to the right. Levamisole potentiated the pressor responses to noradrenaline, angiotensin and acetylcholine. The effects of levamisole are ascribed to inhibition of monoamine oxidase, catechol-O-methyl transferase, catecholamine uptake2 mechanism and cholinesterase.

Adrenalectomy↗
PubMed1987

Effect of mercury on rabbit myelin CNP-ase in vitro.

2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) catalyzes hydrolysis of 2',3'-cyclic nucleotides to form the corresponding 2'-monophosphates. Rabbit myelin fraction with CNPase specific activity between 30-40 mumoles/min/mg protein was incubated in the presence of various inorganic and organic heavy metal compounds: HgCl2; (CH3Hg)OH; Pb(NO3)2; Pb(C2H302)2.3H20; (C2H5)2Pb; (C2H5)3SnCl. The enzyme has been shown to be almost exclusively sensitive to mercurials in microM concentration range. This would arise from the high solubility of mercurials in organic solvents, which allows them to penetrate into hydrophobic regions of the enzyme to react with active sulfhydryl groups. CNP-ase inhibition by methylmercury was biphasic: A reversible, non-competitive inhibition with an apparent Ki = 1 microM occurred after a 5 min preincubation time of the enzyme with the inhibitor. In the case of longer preincubation time, as well as in the presence of HgCl2, the graph of enzyme activity versus protein concentration intercepted the abscissa to the right of the origin, indicating that mercurials are irreversible inhibitors of the enzyme. After 45 min of preincubation of the inhibitors with the enzyme 1 nmol of HgCl2 completely blocks CNP-ase activity equivalent to 15.6 micrograms of myelin protein, whereas 1 nmole of Met-Hg blocks activity in 9.9 micrograms proteins. This apparently irreversible inhibition of CNP-ase activity by HgCl2 could be fully restored by the use of an excess of hydrophobic low molecular weight thiols, lipoic acid being the most efficient. Dithiothreitol, a hydrophilic complexing agent, was potent to reverse the inhibition caused by Met-Hg only during the short time experiments. Both low molecular weight thiols, and also EDTA in the case of inorganic mercury could prevent the inhibition of CNP-ase by mercurials, if preincubated for 15 min with the inhibitors, prior to the addition of the enzyme. The irreversible type of inhibition of CNP-ase by Met-Hg was only partially reversed in the presence of low molecular weight thiols. This suggests that the formation of a metal-mercaptide complex is not the only mechanism of inhibition by methylmercury. The possibility of lipid peroxidation triggered by methylmercury with subsequent inhibition of the enzyme activity was not supported by the experimental results. In fact, myelin associated CNP-ase activity appears to be very resistant to the structural membrane alterations caused by lipid peroxidation.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1987

Dimerization of 2,6-dimethoxyphenol by Aspergillus flavus: evidence for the reaction occurring close to mycelia.

Aspergillus flavus grown on 2,6-dimethoxyphenol as sole carbon source produced tetramethoxy-p-dibenzoquinone by a free radical mechanism. The product was identified by H-nmr and ms. Scanning electron microscopy and light microscopy were used to follow the growth of mycelia and the attachment of crystals to the mycelial surfaces. Formation of dimer was inhibited by the presence of glucose in the medium.

Aspergillus flavus↗
PubMed1985

Stabilization of cytochrome P-450 in hepatocytes by free radical scavengers of different nature.

The stabilizing effects of various free radical scavengers on cytochrome P-450 content in isolated rat hepatocytes were studied. It has been shown that incubation of hepatocytes in vitro leads to spontaneous degradation of cytochrome P-450 to accumulation of lipid peroxidation products, e.g. malonyl dialdehyde (MDA). Activation of lipid peroxidation in hepatocyte suspensions by the Fe2+-ADP+NADPH system results in acceleration of cytochrome P-450 degradation due to a considerable increase in the rate of MDA accumulation. There is experimental evidence about the relationship between these two processes in hepatocytes, i.e. addition of 2-ethyl-6-methyl-3-hydroxypyridine, 2, 6-di(tert)butyl-4-hydroxytoluene, and 1, 2, 3-tri-hydroxybenzene to the incubation medium leads to inhibition of lipid peroxidation and stabilization of cytochrome P-450. 2, 6-di(tert)butyl-4-hydroxytoluene is a much more effective inhibitor of lipid peroxidation in hepatocytes and a more potent stabilizer of cytochrome P-450 than the water soluble 1, 2, 3-trihydroxybenzene and 2-ethyl-6-methyl-3-hydroxypyridine. Hydroxylation of 3,4-benz (alpha) pyrene in hepatocytes is also concomitant with a decrease of MDA accumulation and cytochrome P-450 degradation. Free radical scavengers of phenolic type, both exogenously added or endogenously formed via oxidative metabolism of hydrophobic substrates are powerful stabilizers of cytochrome P-450 in liver cells.

Adenosine Diphosphate↗