Metabolomics is a rapidly developing branch of science that concentrates on identifying biologically active molecules with potential biomarker properties. To define the best biomarkers for diseases, metabolomics uses both models (in vitro, animals) and human, as well as, various techniques such as mass spectroscopy, gas chromatography, liquid chromatography, infrared and UV–VIS spectroscopy and nuclear magnetic resonance. The last one takes advantage of the magnetic properties of certain nuclei, such as ¹H, ¹³C, ³¹P, ¹⁹F, especially their ability to absorb and emit energy, what is crucial for analyzing samples. Among many spectroscopic NMR techniques not only one-dimensional (1D) techniques are known, but for many years two-dimensional (2D, for example, COSY, DOSY, JRES, HETCORE, HMQS), three-dimensional (3D, DART-MS, HRMAS, HSQC, HMBC) and solid-state NMR have been used. In this paper, authors taking apart fundamental division of nuclear magnetic resonance techniques intend to shown their wide application in metabolomic studies, especially in identifying biomarkers.

The aim of this study was to characterize a 1:1 molar ratio of a pharmacologically relevant co-amorphous atorvastatin-irbesartan (ATR-IRB) system obtained by quench cooling of the crystalline ATR/IRB physical mixture for potential use in the fixed-dose combination therapy. The system was characterized by employing standard differential scanning calorimetry (DSC), Fourier transform-infrared spectroscopy (FT-IR), and intrinsic dissolution rate studies. Quantum mechanical calculations were performed to obtain information regarding intermolecular interactions in the studied co-amorphous ATR-IRB system. The co-amorphous formulation showed a significant improvement in the intrinsic dissolution rate (IDR) of IRB over pure crystalline as well as its amorphous counterpart. An unusual behavior was observed for ATR, as the IDR of ATR in the co-amorphous formulation was slightly lower than that of amorphous ATR alone. Short-term physical aging studies of up to 8 h proved that the ATR-IRB co-amorphous system remained in the amorphous form. Furthermore, no physical aging occurred in the co-amorphous system. FT-IR, density functional theory calculations, and analysis of T_g value of co-amorphous system using the Couchman–Karasz equation revealed the presence of molecular interactions between APIs, which may contribute to the increased physical stability.

Resveratrol is a plant-derived phytoalexin found in grapes, red wine and many other plants used in Asian folk medicine. It is extensively studied for pleiotropic biological activity. The most crucial are anticancer and chemopreventive properties. Resveratrol has also been reported to be an antioxidant and phytoestrogen. The phytoestrogenic activity of resveratrol was assayed in different in vitro and in vivo models. Although these works brought some, on the first look, conflicting results, it is commonly accepted that resveratrol interacts with estrogen receptors and functions as a mixed agonist/antagonist. It is widely accepted that the hydroxyl groups are crucial for resveratrol’s cytotoxic and antioxidative activity and are responsible for binding estrogen receptors. In this work, we assayed 11 resveratrol analogues, seven barring methoxy groups and six hydroxylated analogues in different combinations at positions 3, 4, 5 and 3′,4′,5′. For this purpose, recombined estrogen receptors and estrogen-dependent MCF-7 and Ishikawa cells were used. Our study was supported by in silico docking studies. We have shown that, resveratrol and 3,4,4′5′-tetrahydroxystilbene, 3,3′,4,5,5′-pentahydroxystilbene and 3,3′,4,4′,5,5′-hexahydroxystilbene may act as selective estrogen receptor modulators.

Phenolic acids constitute a family of natural compounds that can be found in a wide variety of plants and food. Among them only ferulic, p -coumaric, chlorogenic, and caffeic acids were recently investigated. There are no data about antioxidant activity of single molecules of fertaric, coutaric, caftaric, dactylifric, and neochlorogenic acids and prenyl caffeate. In a continuation of our attempts to clarify their antioxidant activity, we present herein in silico studies concerning four mechanisms of interaction of phenolic antioxidants with free radicals: hydrogen atom transfer (HAT), (sequential proton loss electron transfer (SPLET), single electron transfer followed by proton transfer, and transition metals chelation, determining several parameters such as bond dissociation enthalpy; proton affinity; adiabatic ionization potential; highest occupied molecular orbital, lowest unoccupied molecular orbital, singly occupied molecular orbital; spin density; stabilization energy (Δ E _ISO ); deprotonation enthalpy/energy (Δ H _acidity and Δ G _acidity ); and second-order perturbation energy E (2). We have proved that for all studied compounds the HAT mechanism was preferred in vacuum as well as in benzene and amyl acetate solvent media, whereas SPLET approach was significantly exposed especially in water. The most active antioxidants (according to the HAT approach) were compounds prenyl caffeate, methyl caffeate, and caffeic acid phenethyl ester, whereas the activity of trans and cis isomers of chicoric derivatives was related to the SPLET protocol. We also observed that trans isomers of caffeic, ferulic, and p -coumaric derivatives were not enough effective in all environments, when compared with other studied molecules. Moreover, we have noticed that the ortho position of the phenylic ring influenced profitably on antioxidant activity in all analyzed compounds.