Thylakoid membranes contain two types of quinones, benzoquinone (plastoquinone) and naphthoquinone, which are involved in photosynthetic electron transfer. Unlike the benzoquinone, the chemical species of naphthoquinone present (phylloquinone, menaquinone-4 and 5'-monohydroxyphylloquinone) varies depending on the oxygenic photosynthetic organisms. The green alga Chlamydomonas reinhardtii has be...

the molecular geometry of complex of adenine with 8 water molecules was calculated with hartree-fock (hf). the standard 6-31g(d) basis set has been employed. the existence of c-h…o hydrogen bonds between the water molecules and the hydrophobic part of nucleobase is stablished. we optimized structures and computed interaction energies of all complexes of adenine with water molecules step by step...

A series of poly(p-arylene butadiynylene)s containing zero, one, and two co-facial pi-pi interactions per repeat unit were synthesized and characterized. A surprisingly selective and high-yielding Diels-Alder cycloaddition of anthracene and nonsymmetric, sterically hindered anhydrides proved essential to generating the cofacial arene-containing monomers. Single-crystal X-ray structures display ...

The title compound, C(6)H(6)N(2)O(2), was obtained as a product of an in vitro study of the metabolism of benzofuroxan. The molecule exhibits a amphi configuration of the oxime groups C=N-OH. One oxime group is involved in the formation of a strong intra-molecular O-H⋯N hydrogen bond, while another links mol-ecules into zigzag chains along the c axis via inter-molecular O-H⋯N hydrogen bonds.

A structure consisting of poly(A) complexed with other components is released from polysomes by ribonuclease treatment. The poly(A) complex has a sedimentation value of 12-15, while the corresponding sedimentation value for free poly(A) is 4. The complex does not appear to represent an artifact formed by interaction of free poly(A) with either cytoplasmic or polysomal proteins. The polynucleoti...

The presence of a quinone group in the structure of a series of model compounds was shown to produce cell kill by a mech anism involving free radicals and active oxygen species. Fur thermore, the ability of the compound to bind to DNA appeared to enhance its cytocidal activity. The same model compounds were used to investigate the effect of the quinone group on cellular DNA. DNA single-strand b...