Joseph Corse

Antimicrobial properties of 6,7-dihydroxy-, 7,8-dihydroxy-, 6-hydroxy- and 8-hydroxycoumarins

Abstract The effects of daphnetin, aesculetin, scopoletin, 6-hydroxycoumarin and 8-hydroxycoumarin and their alkyl and acyl derivatives on the growth of bacteria and fungi are reported.

Identification of several components of isochlorogenic acid

Abstract “Isochlorogenic acid” has been shown to be a complex mixture of closely related compounds. Three of the major fractions have been purified and shown by NMR spectroscopy to be 4,5-dicaffeoylquinic acid, 3,4-dicaffeoylquinic acid and 3,5-dicaffeoylquinic acid. A fourth major fraction appears to be a mixture of the 3′-methyl ethers of 3,5-dicaffeoylquinic acid.

Conformation analyses of D-(−)-quinic acid and some of its derivatives by nuclear magnetic resonance

Abstract D -(−)-Quinic acid, eight monoacyl esters, three diacyl esters, and 5-dehydroquinic acid have been examined by NMR spectroscopy and shown to exist in solution in a chair conformation with the carboxyl equatorial. The efiects of this conformation on chemical and physical properties are discussed.

Nondiffusible allergenic contaminant isolated from samples of chlorogenic acid causing allergic reactions: Pure chlorogenic acid not an allergen

Abstract A sample of chlorogenic acid submitted by Sehon and Freedman as the allergen of green coffee was subjected to simple dialysis in cellophane bags. The diffusible low-molecular-weight component (dialysate) contained all of the chlorogenic acid of the original sample but was shown by Prausnitz-Kustner tests to be nonallergenic. The nondiffusible high-molecular-weight component retained within the dialysis bag contained no chlorogenic acid but did contain a coffee-specific antigen that caused positive skin reactions in Prausnitz-Kustner tests with sera from patients with atopy to green coffee. Samples of chlorogenic acid obtained from commerical sources contained nondiffusible antigen. A sample of synthetic chlorogenic acid from M. L. Scarpatis laboratory was found to be without allergenic activity in clinical tests upon French patients with severe allergy to green coffee. Nuclear magnetic resonance (NMR) spectra determined on all samples studied showed that all were correctly identified as chlorogenic acid (3-caffeoylquinic acid). These results together with our previous studies show that the coffee-specific allergenicity (antigenicity) present in some samples of chlorogenic acid is due entirely to protein present as a contaminant. It appears to be highly improbable that chlorogenic acid ever functions as an allergen in human atopic hypersensitivity to materials of plant origin.

3-O-Sinapolyquinic acid

Abstract 3- O -Sinapoylquinic acid has been synthesized and its chromatographic and distribution characteristics described.

Two homogeneous immunoassays for pyridoxamine

Protein conjugates of pyridoxal have been used to elicit anti-vitamin B6 antibodies in rabbits. These antibodies have been incorporated into 2 homogeneous assays systems, a spin immunoassay, using a paramagnetic derivative of the vitamin as ligand, and a fluorescence enzyme immunoassay, using beta-galactosidase conjugated to vitamin B6 as the indicator molecule. These assay systems do not require fractionation steps, and could be the basis of analytical methodology for nutritional research or clinical diagnosis.

Subcellular fractionation of wheat leaf protoplasts by centrifugal elutriation

A new method using centrifugal elutriation for subcellular fractionation of plant cells has been developed. This method takes advantage of the fact that particles sedimenting in a gravitational field can be eluted by flow against the field. A wheat protoplast homogenate was fed into an elutriation rotor spinning at high speed and the flow rate into the rotor was gradually increased. The smaller and less dense materials such as mitochondria, microbodies, endoplasmic reticulum, and cytoplasm were elutriated earlier than the larger and denser nuclei and chloroplasts. The intact chloroplasts, free of mitochondria, microbodies, endoplasmic reticulum, and cytoplasm, could be obtained within 40 min following the rupture of protoplasts. The chlorophyll-free mitochondria could be obtained within 80 min.