NMR Analysis of Extra Virgin Olive Oil of the Epirus Region of Greece with Emphasis on Selected Phenolic Compounds.

Extra virgin olive oil (EVOO) is recognized for its numerous health benefits, attributed to its rich phenolic components. NMR has emerged as a prevalent technique for precisely identifying these compounds. Among Mediterranean countries, Greece stands as the third-largest producer of olives, with the Epirus region notably advancing in olive cultivation, contributing significantly to the dynamic growth of the region. In this study, an NMR method was employed based on the acquisition of a 1H NMR spectrum along with multiple resonant suppression in order to increase the sensitivity. Using the above method, 198 samples of extra virgin olive oil, primarily sourced from the Epirus region, were analyzed, and both the qualitative and quantitative aspects of the phenolic compounds were obtained. In addition, we examined the effects of various factors such as variety, harvest month, and region origin on the phenolic compounds' concentration. The results revealed an average total phenolic content of 246 mg/kg, closely approaching the EU health claim limit of 250 mg/kg. Approximately 15% of the samples were confidently characterized as high-phenolic olive oil. The highest concentrations were observed in the Thesprotia samples, with several Lianolia varieties exceeding the total phenolic content of 400 mg/kg. Statistical tests demonstrated a significant influence of the olive variety and the month of fruit harvest on phenolic component concentration, followed by the region of origin. A very strong correlation was noted between the total phenolics content and the levels of oleocanthal and oleacein, with a correlation coefficient (r) of 0.924. Upon optimization of all factors affecting olive oil quality, the majority of the EVOOs from the Epirus region have the potential to be characterized as high in phenolic content.

Synthesis, characterization, interactions with the DNA duplex dodecamer d(5'-CGCGAATTCGCG-3')2 and cytotoxicity of binuclear η6-arene-Ru(II) complexes.

The novel binuclear η6-arene-Ru(II) complexes with the general formula {[(η6-cym)Ru(L)]2(µ-BL)}(PF6)4, and their corresponding water soluble {[(η6-cym)Ru(L)]2(µ-BL)}Cl4, where cym = p-cymene, L = 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen), BL = 4,4'-bipyridine (BL-1), 1,2-bis(4-pyridyl)ethane (BL-2) and 1,3-bis(4-pyridyl)propane (BL-3), were synthesized and characterized. The structure of {[(η6-cym)Ru(phen)]2(µ-BL-1)}(PF6)4 was determined by X-ray single crystal methods. The interaction of {[(η6-cym)Ru(phen)]2(µ-BL-i)}Cl4 (i = 1, 2, 3; (4), (5) and (6) correspondingly) with the DNA duplex d(5'-CGCGAATTCGCG-3')2 was studied by means of NMR techniques and fluorescence titrations. The results show that complex (4) binds with a Kb = 12.133 × 103 M-1 through both intercalation and groove binding, while (5) and (6) are groove binders (Kb = 2.333 × 103 M-1 and Kb = 3.336 × 103 M-1 correspondingly). Comparison with the mononuclear complex [(η6-cym)Ru(phen)(py)]2+ reveals that it binds to the d(5'-CGCGAATTCGCG-3')2 with a Kb value two orders of magnitude lower than (4) (Kb = 0.158 × 103 M-1), indicating that for the binuclear complexes both ruthenium moieties participate in the binding. The complexes were found to be cytotoxic against the A2780 and A2780 res. cancer cell line with a selectivity index (SI) in the range of 3.0-5.9.