NMR-based quantitative studies of the conformational equilibrium between their square and folded forms of ascidiacyclamide and its analogues.

Ascidiacyclamide [cyclo(-Ile-oxazoline-D-Val-thiazole-)] (1) is a cytotoxic cyclic peptide from the ascidian, or sea squirt. Through structural analyses using asymmetric analogues [Xxx: Ala (2), Val (3), Leu (4), Phe (5), cyclohexylalanine (6) and phenylglycine (7)], we previously showed 1 to exist in a conformational equilibrium between square and folded forms. In the present study, five new asymmetric analogues [Xxx: 2-aminobutyric acid (8), 2-aminopentyric acid (9), -butylalanine (10), cyclohexylglycine (11) and -leucine (12)] were synthesized, and their structures were analyzed with X-ray diffraction and CD spectral measurements.

Water-assisted synthesis of mesoporous calcium carbonate with a controlled specific surface area and its potential to ferulic acid release.

A carbonation process to control the specific surface area of mesoporous calcium carbonate and the dissolution profile of ferulic acid on mesoporous carbonate particles are presented. The effects of water content on the physicochemical properties, specific surface area, pore size, crystallinity, and morphology are evaluated. Mesoporous calcium carbonate particles are synthesised with well-controlled specific surface areas of 38.

Nitric oxide represses the proliferation of Caco-2 cells by inducing S-G/M cell cycle arrest.

There is conflicting data regarding the ability of nitric oxide (NO) to promote or inhibit colorectal cancer cell proliferation. Furthermore, NO reacts rapidly with endogenous superoxide at a diffusion-controlled rate to give peroxynitrite (ONOO), a strong oxidant and nitrating agent. The aim of this study was to assess the effects of exogenous NO and ONOO on the proliferation of the colorectal cancer cell line Caco-2.

Correction: Base recognition by l-nucleotides in heterochiral DNA.

[This corrects the article DOI: 10.1039/C2RA01013E.].

The peptide glycyl-ʟ-histidyl-ʟ-lysine is an endogenous antioxidant in living organisms, possibly by diminishing hydroxyl and peroxyl radicals.

Despite evidence that tripeptide glycyl-ʟ-histidyl-ʟ-lysine (GHK) is an endogenous antioxidant, its mechanism and importance are not fully understood. In the present study, the ability of GHK to reduce levels of reactive oxygen species (ROS) in Caco-2 cells was evaluated by flow cytometry with the oxidation-sensitive fluorescent dye 2',7'-dichlorodihydrofluorescein diacetate. Further, types of ROS diminished by GHK were assessed by utilizing an electron spin resonance (ESR) spin-trapping technique.

Three new cardiac glycosides obtained from the roots of Lour. and their cytotoxic and melanogenesis-inhibitory activities.

Three new cardiac glycosides strophanthidin-3--α-l-rhamnopyranosyl-(1→4)-6-deoxy-βd-allopyranoside (1), 5β-16β-acetylkamaloside (2), and mansonin-19-carboxylic acid (3) along with seven known steroids including five cardiac glycosides were isolated from the methanol extracts of Lour. roots. The structures of these compounds were established by spectroscopic analyses.

A crystal structure study when crystallized only in d(CG)3 + methylamine and a d(CG)3 + metal ion.

There is not an example of the crystallization only of d(CG)(3) and a metallic cation without putting the amine in addition in there is no example of the crystallization d(CG)(3) with methylamine that is the mono-amine so far either. We were able to obtain a very beautiful crystal with all sides of 0.3mm by the sitting drop method that had done the crystallization of d(CG)(3)+ methylamine and d(CG)(3)+ Mg(2 +).

The development of crystallization and X-ray crystallography method of long stem DNA.

We clarified stabilization mechanism of left-handed Z-DNA by X-ray crystal structure analysis. I was able to achieve it by burying big minor groove of Z-DNA because metal ion and polyamine connected it to minor groove of Z-DNA. On that occasion I understood that an electric charge and length of polyamine gave big influence to a combination brain very much.