6-Aminocoumarin on treatment with oxalyl chloride gives coumarinyl-6-isocynate (1a-c) which on treatment with glycine gives 1H-3-[2'-oxo-2'H-benzopyran-6'-yl]-5-imidazolidine-2, 4-dione (2a-c). (2a-c) when refluxed with o-chlorobenzaldehyde, m-hydroxybenzaldehyde, 3,4-dimethoxybenzaldehyde and 3-nitrobenzaldehyde separately gives 1H-5-(2"-chlorobenzylidene)-3-(2'-oxo-2'H-benzopyran-6'-yl) imida...

Intracellular antioxidants, glutathione and ascorbate, and two molecular markers of oxidative DNA damage, 5-hydroxy-2'-deoxycytidine (5-OH-dCyd) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo), were measured in lymphocytes from 105 healthy volunteers. The analysis of 5-OH-dCyd and 8-oxo-dGuo was carried out by HPLC with electrochemical detection such that both compounds were detected on th...

BACKGROUND Coumarin and their derivatives are important and useful compounds with diverse pharmacological properties. In the present study, we evaluated the in vitro cytotoxic activity of new acetoxycoumarin derivatives: 4-(7-methoxy-4-methyl-2-oxo-2H-chromen-3-yl)phenyl acetate (1), 4-(1-methyl-3-oxo-3H-benzo[f]chromen-2-yl)phenyl acetate (2), 4-(6-propionamido-4-methyl-2-oxo-2H-chromen-3-yl) ...

1. The effect of the branched-chain amino acids, namely leucine, isoleucine and valine and their corresponding 2-oxo acids on the metabolism of 2-oxoglutarate by developing rat and human brain preparations was investigated. 2. The decarboxylation of 2-oxo[1-(14)C]glutarate to (14)CO(2) by mitochondria from adult rat brain was inhibited by the branched-chain 2-oxo acids whereas the branched-chai...

Human NUDT5 (hNUDT5) hydrolyzes various modified nucleoside diphosphates including 8-oxo-dGDP, 8-oxo-dADP and ADP-ribose (ADPR). However, the structural basis of the broad substrate specificity remains unknown. Here, we report the crystal structures of hNUDT5 complexed with 8-oxo-dGDP and 8-oxo-dADP. These structures reveal an unusually different substrate-binding mode. In particular, the posit...

Photoisomerization processes involving five isomers of cytosine were induced by narrowband tunable UV irradiation of matrix-isolated monomers of the compound. Irradiation of an argon matrix containing cytosine monomers with UV λ = 313 nm laser light resulted in syn↔anti photoisomerizations between the two imino-oxo forms, whereas the substantially more populated amino-hydroxy and amino-oxo form...

The incubation of 15beta-hydroxy-3-oxo-ent-kaur-16-ene (1) with the fungus Gibberella fujikuroi afforded 11beta-hydroxy-3,15-dioxo-ent-kaurane (6), 11beta,15beta-dihydroxy-3-oxo-ent-kaur-16-ene (8), 7beta,11beta,15beta-trihydroxy-3-oxo-ent-kaur-16-ene (9), 7alpha,11beta-dihydroxy-3,15-dioxo-ent-kaurane (7), and 7alpha,11beta,15beta-trihydroxy-3-oxo-ent-kaur-16-ene (10). The incubation of 15beta...

BACKGROUND Cancers have dysfunctional redox regulation resulting in production of reactive oxygen species (ROS), damaging DNA, RNA and free NTPs, and causing the accumulation of oxidative nucleic acids in cytoplasm. The major types are 8-oxo-7,8-dihydroguanine(8-oxoGsn) in RNA and 8-oxo-7,8-dihydro-2' deoxyguanosine(8-oxodGsn) in Mt-DNA. The MTH1 protein sanitizes oxidized nucleotide pools from...

Oxidative stress contributes to genomic instability in chronic lymphocytic leukemia (CLL), but its relationship with the acquisition of specific chromosomal abnormalities is unknown. We recruited 55 untreated CLL patients and assessed 8-oxo-2'-deoxyguanosine (8-oxo-dG), glutathione, and malondialdehyde (MDA) levels, and we compared them among the cytogenetic subgroups established using fluoresc...