Quantitative determination of hexylresorcinol in commercial antiseptic solution by high-pressure liquid chromatography.

High-pressure liquid chromatography was used with a 5-micron silica gel column to quantitate hexylresorcinol in a commercial antiseptic solution following extraction with methylene chloride. This method shows linearity to at least 0.025% hexylresorcinol. A mobile phase consisting of 63% heptane, 34% chloroform, and 5% methanol was used with a UV detector (254 nm) and a flow of 3 ml/min. No interfering substances were observed.

High-pressure liquid chromatographic determination of camphor and parachlorophenol in camphorated parachlorophenol.

Quantitative analyses of both camphor and parachlorophenol in camphorated parachlorophenol by high-pressure liquid chromatography is described. A 5% solution of phenol in the mobile phase (heptane-chloroform 3:2) served as the internal standard; the assay involved addition of this phenol solution to the camphorated parachlorophenol, followed by further dilution using the mobile phase (heptane-chloroform, 3:2) and injection into the instrument.

Alkylamine salts and amides: in vitro inhibition of S mutans 6715.

Our studies with the salts and amides of alkylamines have shown that the undecylenate salts have significant in vitro activity against S mutans No 6715, suggesting that these agents are worthy of additional evaluation. The attempt to increase activity by combining undecylenic acid with the alkylamines was not successful; however, better attachment to tooth surfaces and/or retention during washing did occur. Our results suggest that the free amino group of alkylamines and the free acid group of undecylenic acid are required for these two classes of agents to demonstrate antibacterial activity.

Quantitative determination of phenol by high-pressure liquid chromatography.

High-pressure liquid chromatography was used with a 5-micrometer silica gel column to quantitate the phenol in phenolated calamine lotion USP and a commercial antiseptic solution. This method requires less than 10 min/assay, and other compounds present in the products analyzed did not interfere.

Sulfur-containing derivatives of amphetamine: thioureas, methanesulfonamides, and trifluoromethanesulfonamides.

N-Methylthiourea, methanesulfonamide, and trifluoromethanesulfonamide derivatives of amphetamine, 4-nitroamphetamine, and 4-aminoamphetamine were synthesized. The N-methylthiourea derivative of amphetamine, as well as the triethylammonium salt of the dithiocarbamate, produced significant depressor effects in normotensive dogs. N,N'-Bis(methanesulfonyl)-1-methyl-2-(4-aminophenyl)ethylamine and N-trifluoromethanesulofonyl-1-methyl-2-phenylethylamine, but not N-methanesulfonyl-1-methyl-2-phenylethylamine and N-trifluoroacetyl-1-methyl-2-(4-trifluoromethanesulfonamido-phenyl))ethylamine, showed significant antiobesity effects in rats.

Quantitative structure-activity relationships for 5-substituted 8-hydroxyquinolines as inhibitors of dental plaque.

Fourteen 8-hydroxyquinolines were tested for antiplaque activity by measuring their minimum inhibitory concentrations [MIC (M)] against Streptococcus mutans No. 6715. Linear regression analysis was conducted with the MIC (M) values and hydrophobic (log P), electronic (beta, pKaOH, pKaN), and steric [molar refractivity (MR), molecular weight (mol wt)] parameters. The best correlation (r2 = 0.90) was obtained with MR, log P, and beta. The smaller the steric contribution of the 5-substituent, the more active the compound. The parent 8-hydroxyquinoline was the most active. The negative contribution toward activity by 5-substituents larger than hydrogen can be overcome by the positive contributions of groups that are lipophilic and electron withdrawing; for example, the 5-chloro derivative is as active as the parent 8-hydroxyquinolines.

Catechol O-methyltransferase. 8. Structure-activity relationships for inhibtion by 8-hydroxyquinolines.

A series of 5- and 7-substituted 8-hydroxyquinolines was evaluated as inhibitors of catechol O-methyltransferase (COMT, E.C. 2.1.1.6). The electronic character of the substituents in the 5 position appeared to have only a small effect if any on the inhibitory activity of these compounds. A significant factor which contributes to the inhibitory activity of these compounds appears to be the nature of the 7-substituent. The structure-activity relationship for this series of inhibitors is discussed relative to the nature of the enzymatic binding site.

A physiochemical approach to the study of amines as antiplaque agents.

Alkyl and aromatic amines were evaluated for inhibitory activity against S mutans 6715. Only the alkylamines were active and this may be due to their greater basicity. The agents that showed good activity were decylamine, dodecylamine, tetradecylamine, and hexadecylamine. In addition to the free bases, the hydrochloride and hydrofluoride salts were also tested for inhibitory activity and the same four agents were shown to be most active. These agents appear to hold good promise as antiplaque agents against S mutans 6715, therefore, further in vitro studies against other plaque-forming bacteria and toxicological and clinical evaluation seems to be warranted to determine the best clinical agent.

Synthesis and in vitro evaluation of 8-hydroxyquinoline analogs as inhibitors of dental plaque.

A group of 5-substituted 8-hydroxyquinolines with predicted log P values in the 1-4 range has been prepared from either 8-hydroxyquinoline or its appropriate derivative. 5-Formyl-, 5-iodo-, 5-fluoro-, 5-acetyl-, and 5-methoxymethyl-8-hydroxyquinoline in addition to methyl-5(8-hydroxyquinolyl)acetate and ethyl 5-(8-hydroxyquinolyl)acetate displayed greater in vitro antiplaque activity than 8-hydroxyquinoline.