|
| ||
|
|
||
Chlorophyll Derivatives (chlorophyll + derivative)
Selected AbstractsAntioxidant and Antimutagenic Activity of Dietary Chlorophyll Derivatives Determined by Radical Scavenging and Bacterial Reverse Mutagenesis AssaysJOURNAL OF FOOD SCIENCE, Issue 7 2002M.G. Ferruzzi ABSTRACT: In vitro antioxidant and antimutagenic activity of dietary chlorophyll derivatives was assessed. Antioxidant activity was determined by the ability of each compound to scavenge the long-lived free radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2,-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS+). Antimutagenic activity was assayed with a modified microscreen bacterial reverse mutagenicity assay using Salmonella typhimurium TA100 and benzo[a]pyrene as the tester strain and mutagen respectively. Derivatives of chlorophyll a were found to be more effective radical quenchers than those of chlorophyll b. Furthermore, metal-free derivatives such as chlorins, pheophytins, and pyropheophytins exhibited significantly lower antiradical capacity than metallo-derivatives such as Mg-chlorophylls, Zn-pheophytins, Zn-pyropheophytins, Cu-pheophytina, andCu-chlorophyllins. Both metal-free and metallo-chlorophyll derivatives demonstrated similar dose-dependent inhibitory activity against B[a]P induced mutagenesis. These results demonstrate that dietary chlorophyll derivatives prevalent in both fresh and processed foods and dietary supplements have antioxidant and antimutagenic activities. [source] Design, synthesis and properties of synthetic chlorophyll proteinsFEBS JOURNAL, Issue 11 2001Harald K. Rau A chemoselective method is described for coupling chlorophyll derivatives with an aldehyde group to synthetic peptides or proteins modified with an aminoxyacetyl group at the ,-amino group of a lysine residue. Three template-assembled antiparallel four-helix bundles were synthesized for the ligation of one or two chlorophylls. This was achieved by coupling unprotected peptides to cysteine residues of a cyclic decapeptide by thioether formation. The amphiphilic helices were designed to form a hydrophobic pocket for the chlorophyll derivatives. Chlorophyll derivatives Zn-methylpheophorbide b and Zn-methyl-pyropheophorbide d were used. The aldehyde group of these chlorophyll derivatives was ligated to the modified lysine group to form an oxime bond. The peptide,chlorophyll conjugates were characterized by electrospray mass spectrometry, analytical HPLC, and UV/visible spectroscopy. Two four-helix bundle chlorophyll conjugates were further characterized by size-exclusion chromatography, circular dichroism, and resonance Raman spectroscopy. [source] Antioxidant and Antimutagenic Activity of Dietary Chlorophyll Derivatives Determined by Radical Scavenging and Bacterial Reverse Mutagenesis AssaysJOURNAL OF FOOD SCIENCE, Issue 7 2002M.G. Ferruzzi ABSTRACT: In vitro antioxidant and antimutagenic activity of dietary chlorophyll derivatives was assessed. Antioxidant activity was determined by the ability of each compound to scavenge the long-lived free radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2,-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS+). Antimutagenic activity was assayed with a modified microscreen bacterial reverse mutagenicity assay using Salmonella typhimurium TA100 and benzo[a]pyrene as the tester strain and mutagen respectively. Derivatives of chlorophyll a were found to be more effective radical quenchers than those of chlorophyll b. Furthermore, metal-free derivatives such as chlorins, pheophytins, and pyropheophytins exhibited significantly lower antiradical capacity than metallo-derivatives such as Mg-chlorophylls, Zn-pheophytins, Zn-pyropheophytins, Cu-pheophytina, andCu-chlorophyllins. Both metal-free and metallo-chlorophyll derivatives demonstrated similar dose-dependent inhibitory activity against B[a]P induced mutagenesis. These results demonstrate that dietary chlorophyll derivatives prevalent in both fresh and processed foods and dietary supplements have antioxidant and antimutagenic activities. [source] Characterization of the Photochromic Pigments in Red Fluorescent Proteins Purified from the Gut Juice of the Silkworm Bombyx mori L.PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 6 2008Santosh G. Sunagar Multiple forms of red fluorescent proteins (RFPs) were observed in the gut juice of the silkworm, Bombyx mori L. It is to be noted that only one RFP band is reported in the literature so far. However, we report here three electrophoretically separated RFPs (A, B and C) found to be heterogeneous with respect to their components, namely the protein part and the fluorescent tetrapyrrole pigment moiety. Of the three RFPs, band C was found to be a glycoprotein. The absorption extinction coefficients and fluorescence quantum yields of the three RFPs were estimated. Further, this is the first communication demonstrating the presence of three different chlorophyll derivatives associated with the three different RFPs. The pigments were analyzed by thin layer chromatography followed by their elution to characterize the pigments by spectrophotometric and spectrofluorometric methods. Spectral characteristics have led to the identification of monovinyl chlorophyllide a, divinyl protochlorophyllide a and monovinyl pheophytin a as being associated with RFP bands A, B and C, respectively. These three purified RFPs can serve as the source of the three pigments as the standards. [source] | ||||||||||