Biolocalisation and photochemical properties of novel macrocyclic photosensitisers, guanidiniocarbonyl-substituted tetraphenylporphyrin (1) and sugar-substituted sapphyrin (2) were investigated by spectroscopic methods. Both photosensitisers absorb in far visible region and showed good tumour localisation. Photosensitiser 2 demonstrated significantly larger absolute and relative to normal tissue (T/N) amount in tumour (330 microg g(-1) wet tissue, T/N=19.0) than photosensitiser 1 did (13 microg g(-1) wet tissue, T/N=2.1). According to iodometric and uric acid assays, compound 1 produced large amount of 1O2 (phidelta=0.60-0.68), while compound 2 showed non-significant 1O2 production (phidelta=0.04). The electronic spectroscopic study confirms that only photosensitiser 1 is able to mediate photooxidation of model compounds (BSA, poly(Trp), Tyr, Trp, and GMP) after light irradiation. Pour photochemical activity of compound 2 was explained by its self-aggregation. Raman spectroscopic study indicated that monomerised photosensitiser 2 effectively damaged BSA and calf thymus DNA after light excitation at the conditions of high excess of these macromolecules.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.jphotobiol.2004.02.003 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Improving ultrafiltration efficiency of acidified skim milk using bipolar membrane electrodialysis: Impact on protein concentrate composition, process performance, and fouling.
Food Res Int
January 2025
Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark. Electronic address:
The efficiency of ultrafiltration (UF) of acidified skim milk (SM) is impaired by protein aggregation and mineral scaling. The aim of this study is to assess the potential of acidification by electrodialysis with bipolar membranes (EDBM), in comparison with citric acid (CA), prior to the UF process on filtration performance, fouling and composition of the protein concentrates. Electro-acidification, facilitated by a water-splitting reaction, decreased the pH of milk to ∼ 5.
View Article and Find Full Text PDFPhotodynamic inactivation mediated by natural alizarin on bacteria for the safety of fresh-cut apples.
Food Res Int
January 2025
College of Food Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China. Electronic address:
Most photosensitizers have limited responsiveness to visible light, however, visible light is a light source with a wide range of wavelengths and the most common in daily life, and making full use of visible light can help to enhance the photodynamic antimicrobial properties of photosensitizers. To tackle this issue, this study confirmed that alizarin has a good absorption capacity for visible light by UV-DRS analysis. Theoretical calculations showed that alizarin might be excited through the charge transfer (CT) mechanism.
View Article and Find Full Text PDFNMR spectroscopic studies of chitin oligomers - Resolution of individual residues and characterization of minor amide cis conformations.
Carbohydr Polym
March 2025
Department of Molecular Sciences, Swedish University of Agricultural Sciences, Almas Allé 5, Uppsala 75651, Sweden. Electronic address:
Chitin is the second most abundant biopolymer in nature after cellulose and is composed of N-acetylglucosamine (GlcNAc) connected via β(1 → 4)-glycosidic bonds. Despite its prominence in nature and diverse roles in pharmaceutical and food technological applications, there is still a need to develop methods to study structure and function of chitin and its corresponding oligomers. Efforts have been made to analyse chitin oligomers by NMR spectroscopy, but spectral overlap has prevented any differentiation between the interior residues.
View Article and Find Full Text PDFA Complete Description of the Ultrafast Proton Transfer Dynamics in the Excited State of D-Luciferin.
J Phys Chem B
January 2025
UM-DAE Centre for Excellence in Basic Sciences, Kalina Campus of Mumbai University, Santacruz (E), Mumbai 400098, India.
Excited-state proton transfer (ESPT) in organic photoacids is a widely studied phenomenon in which D-luciferin is of special mention, considering the fact that apart from its phenolic OH group, the nitrogen atoms at either of the two thiazole moieties could also participate in hydrogen bonding interactions with a proton-donating solvent during ESPT. As a result, several transient species could appear during the ESPT process. We hereby deploy subpicosecond time-resolved fluorescence upconversion (FLUP) and transient absorption (TA) spectroscopic techniques to understand the detailed photophysics of D-luciferin in water as well as in dimethyl sulfoxide (DMSO) and ethanol.
View Article and Find Full Text PDFNew C-linked diarylheptanoid dimers as potential α-glucosidase inhibitors evidenced by biological, spectral and theoretical approaches.
Int J Biol Macromol
January 2025
Key Laboratory of Phytochemistry and Natural Medicines, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China. Electronic address:
Diabetes mellitus (DM) is a chronic metabolic disorder characterized by elevated blood glucose levels, generally due to defects of insulin action or secretion. Inhibition of α-glucosidase, an enzyme responsible for carbohydrate degradation, is a promising strategy for managing postprandial hyperglycemia in diabetic patients. In this study, two new C-linked diarylheptanoid dimers, kaemgalanganols A (1) and B (2), were isolated from K.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!