Search results for "Mace"

Never Cared for What They Do: High Structural Stability of Guanine-Quadruplexes in the Presence of Strand-Break Damage

2022

DNA integrity is an important factor that assures genome stability and, more generally, the viability of cells and organisms. In the presence of DNA damage, the normal cell cycle is perturbed when cells activate their repair processes. Although efficient, the repair system is not always able to ensure complete restoration of gene integrity. In these cases, mutations not only may occur, but the accumulation of lesions can either lead to carcinogenesis or reach a threshold that induces apoptosis and programmed cell death. Among the different types of DNA lesions, strand breaks produced by ionizing radiation are the most toxic due to the inherent difficultly of repair, which may lead to genomi…

2α-Hydroxyalantolactone from Pulicaria undulata: activity against multidrug-resistant tumor cells and modes of action.

2020

Abstract Background Sesquiterpene lactones having α-methylene-γ-lactone moiety are promising natural metabolites showing various biological activity. One of the major metabolites isolated from Pulicaria undulata, 2α-hydroxyalantolactone (PU-1), has not been investigated in detail yet. Multidrug resistance (MDR) represents a major obstacle for cancer chemotherapy and the capability of novel natural products to overcoming MDR is of great interest. Purpose Exploring the molecular modes of action for potent natural product metabolites. Methods The resazurin reduction assay was employed to evaluate the cytotoxicity of PU-1 on sensitive and their corresponding drug-resistant cell lines (overexpre…

Arbutin synthase, a novel member of the NRD1β glycosyltransferase family, is a unique multifunctional enzyme converting various natural products and …

2002

Plant glucosyltransferases (GTs) play a crucial role in natural product biosynthesis and metabolization of xenobiotics. We expressed the arbutin synthase (AS) cDNA from Rauvolfia serpentina cell suspension cultures in Escherichia coli with a 6 x His tag and purified the active enzyme to homogeneity. The recombinant enzyme had a temperature optimum of 50 degrees C and showed two different pH optima (4.5 and 6.8 or 7.5, depending on the buffer). Out of 74 natural and synthetic phenols and two cinnamyl alcohols tested as substrates for the AS, 45 were accepted, covering a broad range of structural features. Converting rates comparable to hydroquinone were not achieved. In contrast to this broa…

Acetyltransfer in natural product biosynthesis--functional cloning and molecular analysis of vinorine synthase.

2004

Vinorine synthase (EC 2.3.1.160) catalyses the acetyl-CoA- or CoA-dependent reversible formation of the alkaloids vinorine (or 11-methoxy-vinorine) and 16-epi-vellosimine (or gardneral). The forward reaction leads to vinorine, which is a direct biosynthetic precursor along the complex pathway to the monoterpenoid indole alkaloid ajmaline, an antiarrhythmic drug from the Indian medicinal plant Rauvolfia serpentina. Based on partial peptide sequences a cDNA clone was isolated and functionally expressed in Escherichia coli. The Km values of the native enzyme for gardneral and acetyl-CoA were determined to be 7.5 and 57 microM. The amino acid sequence of vinorine synthase has highest level of i…

Transition Metal Complexes as DNA-intercalators

2008

DNA Binding and Biological Activity of Transition Metal Complexes

2011

The interaction of DNA with metal complexes: experimental and computational studies

2011

DNA interaction and biological activity of first row transition metal complexes

2011

IL DNA PUÒ ANCORA ESSERE CONSIDERATO UN BERSAGLIO D’ELEZIONE PER LO SVILUPPO DI NUOVI FARMACI ANTITUMORALI?

2012

Polish Yellow Sweet Clover (Melilotus officinalis L.) Honey, Chromatographic Fingerprints, and Chemical Markers

2017

A case study of Polish Melilotus officinalis honey was presented for the first time. Gas chromatography–mass spectrometry (GC-MS) (after steam distillation, Soxhlet extraction, ultrasonic solvent extraction, and solid phase extraction (SPE)) and targeted high performance liquid chromatography with a photodiode array detector (HPLC-PAD) were applied to determine the characteristic components of honey. While ubiquitous in most honeys, carbohydrates, terpene derivatives, and phenylacetic acid dominated in the Soxhlet extracts (25.54%) and in the application of SPE (13.04%). In addition, lumichrome (1.85%) was found, and may be considered as a marker of this honey. Due to the presence of these …