The conformational space of dipeptide models derived from glycine, alanine, phenylalanine, proline, tyrosine, and cysteine has been searched extensively and compared with the corresponding C(α) dipeptide radicals at the G3(MP2)-RAD level of theory. The results indicate that the (least-substituted) glycine dipeptide radical is the thermochemically most stable of these species. Analysis of the structural parameters indicates that this is due to repulsive interactions between the C(α) substituents and peptide units in the radical. A comparison of the conformational preferences of dipeptide radicals and their closed-shell parents also indicates that radical stability is a strongly conformation-dependent property.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/chem.201002620 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Three New Dipeptide and Two New Polyketide Derivatives from the Mangrove-Derived Fungus sp.: Antioxidant Activity of Two Isolated Substances.
Mar Drugs
December 2024
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology/Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
Five new metabolites, including three cyclic dipeptide derivatives (-) and two new polyketides (-), together with nine known ones (- and -), were isolated from the mangrove-sediments-derived fungus sp. SCSIO 41431. Their structures were determined using detailed NMR, MS spectroscopic analyses, and quantum chemical calculations.
View Article and Find Full Text PDFSequential Photocatalysis for Homologative Diversification of α-Amino Acids to β-Amino Acids Via Phosphonium Ylide Linchpin Strategy.
J Am Chem Soc
December 2024
Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan.
β-Amino acids serve as crucial building blocks for a broad range of biologically active molecules and peptides with potential as peptidomimetics. While numerous methods have been developed for the synthesis of β-amino acids, most of them require multistep preparation of specific reagents and substrates, which limits their synthetic practicality. In this regard, a homologative transformation of abundant and readily available α-amino acids would be an attractive approach for β-amino acid synthesis.
View Article and Find Full Text PDFNovel application of cyclo(-Phe-Pro) in mitigating aluminum toxicity through oxidative stress alleviation in wheat roots.
Environ Pollut
December 2024
MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou, 310058, China. Electronic address:
Microbial secondary metabolites are crucial in plant-microorganism interactions, regulating plant growth and stress responses. In this study, we found that cyclo(-Phe-Pro), a proline-based cyclic dipeptide secreted by many microorganisms, alleviated aluminum toxicity in wheat roots by increasing root growth, decreasing callose deposition, and decreasing Al accumulation. Cyclo(-Phe-Pro) also significantly reduced Al-induced reactive oxygen species (ROS) with HO, O, and •OH levels decreasing by 19.
View Article and Find Full Text PDFFour Tremulanes and Two Pyroglutamate-Containing Dipeptides from the Mangrove Endophytic Fungus Phaeosphaeriopsis sp. P11.
Chem Biodivers
October 2024
School of Pharmaceutical Sciences, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, China.
Article Synopsis
- * Phaeosphaerienols A-C (1-3) are unique due to their tremulane structure featuring a 1,10-epoxide group, while their structures were determined using various scientific methods, including NMR and X-ray analysis.
- * The isolated compounds were tested for cytotoxicity, antibacterial properties, and free radical scavenging
Equipping Uridine with Three Dipeptide Motifs for the Inhibition of Radical-Induced DNA Oxidation.
J Org Chem
September 2024
Department of Organic Chemistry, College of Chemistry, Jilin University, Changchun 130021, People's Republic of China.
We report the discovery and characterization of antioxidative effects of uridine linked with three dipeptide motifs against DNA oxidation induced by peroxyl radicals. First, the dipeptide motifs are constructed by using the Ugi four-component reaction (Ugi 4CR), in which caffeic, ferulic, sinapic, and syringic acids are used as the carboxylic acid resources, vanillin, benzaldehyde, and -hydroxybenzaldehyde are used as the aldehyde resources, tyramine- and dopamine-related isocyanides as well as ethyl isocyanoacetate are used as the isocyanide resources, and 2-(-aminophenyl)ethanol is used as the amine component. We found that the antioxidative effects of the Ugi 4CR products are 1.
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!