Identity of daniellic acid with illurinic acid

African copaiba balsam is the product of Daniellia olliveri (Rolfe) Hutch. and Dalz. Daniellic acid is identical with illurinic acid.     

Legume lectins interact with muramic acid and N-acetylmuramic acid

The inhibitory potency of both muramic acid (MurAc) and N-acetylmuramic acid (MurNAc) on various legume lectins, including Glc/Man- and Gal/GalNAc-specific lectins, was investigated by a haemagglutination inhibition technique. Data indicated that many lectins, especially those specific for Glc/Man, specifically interact with MurAc and MurNAc often to a greater extent than with other monosaccharides and their derivatives, such as N-acetylglucosamine (GlcNAc) and sialic acid. Glc/Man-specific lectins were also shown to interact with the muramyl-dipeptide MurNAc-D-Ala-D-isoGln. These interactions could explain why various lectins readily agglutinate some bacterial strains of which cell walls contain peptidoglycans with high amounts of MurNAc.     

Reaction of linoleic acid hydroperoxide with thiobarbituric acid.

The linoleic acid hydroperoxide obtained by enzymatic peroxidation of linoleic acid was found to react with thiobarbituric acid to yield a red pigment. The optimum pH for the reaction was found to be 4.0. In the early stages of peroxidation of linoleic acid, thiobarbituric acid value, the amount of conjugated diene, oxygen consumption, and peroxide value were in parallel with one another. The data were compared with those on peroxidation of linolenic acid and arachidonic acid.     

Sialic acid interference with the thiobarbituric acid method for measuirng 3-deoxyoctulosonic acid.

Sialic acid produced an interfering color in an assay designed for measuring 3-deoxyoctulosonic acid. The color yield from sialic acid was not as high as that from 3-deoxyoctulosonic acid but was high enough to cause concern about problems arising when sialic acid-containing substances are present in preparations of bacterial lipopolysaccharides. The instabilityof 3-deoxyoctulosonic acid in acidic media led to reduced color yields. In general, the results suggested that data generated by the application of the thiobarbituric acid method to the measurement of 3-deoxyoctulosonic acid should be approached with caution.     

Chemiluminescence associated with amino acid oxidation mediated by hypochlorous acid

Although most amino acids readily react with hypochlorous acid (HOCl), only the reaction involving tryptophan (Trp) produces a measurable chemiluminescence (CL). Most of this luminescence takes place after total consumption of HOCl when the process is carried out in an excess of Trp. The quantum yield of the process is relatively low (2 × 10^?8 Einstein/mol HOCl reacted). The luminescence is attributed to free radical‐mediated secondary reactions of the initially produced chloramines. This is supported by experiments showing that the chloramines produced when HOCl reacts with alanine are able to induce Trp chemiluminescence, and that this luminescence is partially quenched by free radical scavengers. The spectral changes and the effect of pH upon the observed luminescence are compatible with light emission from products produced in the free radical oxidation of Trp. Copyright © 2002 John Wiley & Sons, Ltd.     

Gelatinization with formic acid.

1. A study has been made of the gelatins obtained by treating a number of fresh and fossil collagens with dilute formic acid. 2. Compositions of their peptides separated by filtration through polyacrylamide gels has been established. 3. Solubilization results in the freeing of much aspartic acid and less glycine, the amounts being determined for the collagens investigated.     

Conjugation of aspartic acid with 4-bromophenylacetic acid,an auxin analogue of aspartic acid

Tobacco mesophyll protoplasts conjugate the auxins indoleacetic acid and naphthaleneacetic acid with aspartic acid very efficiently. This conjugation was found to be correlated with the toxicity of these molecules to protoplast-derived cells grown at low densities. Among a series of halogenated phenylacetic acids, 4-bromophenylacetic was toxic to cells grown at low densities although not able to stimulate proliferation at high cell densities, as opposed to indoleacetic acid and naphthaleneacetic acid. [¹⁴C-car☐yl]-4-bromophenylacetic acid was conjugated with aspartic acid by tobacco protoplasts. Although 4-bromophenylacetic acid is not an auxin, this molecule shares with auxins some of their properties.     

New derivatives of picolinic acid and nicotinic acid with anticonvulsant activity

Previously obtained Pic-BZA is a potent anticonvulsant with low neurotoxicity, but its half-time of action is only about 15 min. In search for equally effective anticonvulsants but with a longer time of action fourteen Pic-BZA analogs were obtained. The compounds were evaluated in the Anticonvulsant Screening Project (ASP) of Antiepileptic Drug Development Program (ADDP) of NIH. Picolinic acid 2-fluorobenzylamide (Pic-2-F-BZA, 7) appeared to be the most effective compound of the series.     

Interactions of human serum albumin with chlorogenic acid and ferulic acid

The interactions of chlorogenic acid and ferulic acid with human serum albumin (HSA) have been investigated by fluorescence and Fourier transformed infrared (FT-IR) spectrometry. Fluorescence results showed that one molecule of protein combined with one molecule of drugs at the molar ratio of drug to HSA ranging from 1 to 10, and their binding affinities (KA) are 4.37 x 10(4) M(-1) and 2.23 x 10(4) M(-1) for chlorogenic acid and ferulic acid, respectively. The primary binding site for chlorogenic acid is most likely located on IIA and that for ferulic acid in IIIA. The main mechanism of protein fluorescence quenching was static quenching process. Combining the curve-fitting results of infrared amide I and amide III bands, the alterations of protein secondary structure after drug complexation were estimated. With increasing the drug concentration, the protein alpha-helix structure decreased gradually and the reduction of protein alpha-helix structure reached about 7% and 5% for protein binding with chlorogenic acid and ferulic acid individually at the drug to protein molar ratio of 30. This indicated a partial unfolding of HSA in the presence of the two acids. From the fluorescence and FT-IR results, the binding mode was discussed.