Association between cognitive function and supplementation with omega-3 PUFAs and other nutrients in ≥ 75 years old patients: A randomized multicenter study

A few studies have assessed the association between omega-3 polyunsaturated fatty acids (n-3 PUFA) and cognitive impairment (CI) in very old adults. The aim of this study was to evaluate the effect of a multinutrient supplementation rich in n-3 PUFA on the cognitive function in an institutionalized ≥75-year-old population without CI or with mild cognitive impairment (MCI). A multicenter placebo-controlled double-blind randomized trial was conducted between 2012 and 2013. Cognitive function was assessed at baseline and after one year using 4 neuropsychological tests. Nutritional status was assessed using Mini Nutritional Assessment (MNA). Interaction between Mini-Mental State Examination (MMSE) score and nutritional status were analyzed using linear regression models. A total of 99 participants were randomized to receive placebo or pills rich in n-3 PUFA. After 1-year follow-up, both groups decreased their MMSE score (-1.18, SD:0. 53 and -0.82, SD:0. 63, p = 0.67 for the control and the intervention group respectively). The memory subscale of the MMSE showed an improvement (+0.26, SD:0.18) in the intervention group against a worsening in the control group (-0.11, SD: 0.14; p = 0.09 for differences between groups). Patients at intervention group with normal nutritional status (MNA ≥24) showed an improvement in the MMSE (+1.03, p = 0.025 for differences between 1-y and baseline measurements) against a worsening in the group with malnutrition (MNA<24) (-0.4, p = 0.886 for differences between 1-y and baseline; p of interaction p = 0.05). Supplementation with n-3 PUFA did not show an improvement in the global cognitive function in institutionalized elderly people without CI or with MCI. They only suggest an apparent improvement in memory loss if previously they were well nourished

Nonhalogenated organic molecules from Laurencia algae

The marine red algae of the genus Laurencia have produced more 700 secondary metabolites and exhibited high molecular diversity and intriguing bioactivity. Since the halogenated structures have been comprehensively reviewed previously, this review, covering up to the end of 2012, mainly focuses on the source, structure elucidation, and bioactivity of nonhalogenated organic molecules from Laurencia spp. as well as the relationship between nonhalogenated and halogenated products. Overall, 173 new or new naturally occurring compounds with 58 skeletons, mainly including sesquiterpenes, diterpenes, triterpenes, and C15-acetogenins, are described.The marine red algae of the genus Laurencia have produced more 700 secondary metabolites and exhibited high molecular diversity and intriguing bioactivity. Since the halogenated structures have been comprehensively reviewed previously, this review, covering up to the end of 2012, mainly focuses on the source, structure elucidation, and bioactivity of nonhalogenated organic molecules from Laurencia spp. as well as the relationship between nonhalogenated and halogenated products. Overall, 173 new or new naturally occurring compounds with 58 skeletons, mainly including sesquiterpenes, diterpenes, triterpenes, and C-15-acetogenins, are described

Multiple metal binding to the 9-methyladenine model nucleobase involving N1, N6, and N7: Discrete di- and trinuclear species with different combinations of monofunctional Pd II and Pt II entities

Several di- and trinuclear metal complexes consisting of the model nucleobase 9-methyladenine (9-MeA) or its mono-deprotonated form (9-MeA -) and monofunctional (dien)Pd II, (dien)Pt II, (NH 3) 3Pt II, or (trpy)Pd II in different combinations have been prepared and/or studied in solution by NMR spectroscopy: [{Pd(dien)} 3(9-MeA-N1,N6,N7)]- Cl 3.5(PF 6) 1.53H 2O (1), [(dien)Pd(N1-9-MeA-N7)Pt(NH 3) 3](ClO 4) 49.33H 2O (2), [(dien)Pt-(N1-9-MeA-N7)Pt(NH 3) 3](ClO 4) 4H 2O (3), and [{(trpy)Pd} 2(N1,N6-9-MeA --N7)Pt(NH 3) 3]- (ClO 4) 53H 2O (4). A migration product of 3, [(dien)Pt(N6-9-MeA- N7)Pt(NH 3) 3] 3+ (3a), has been identified in solution. Unlike Pt-adenine bonds, Pd-adenine bonds are substantially labile, and consequently all Pd-containing complexes discussed here (1, 2, 4) exist in aqueous solution in equilibria of slowly interconverting species, which give rise to individual resonances in the 1H NMR spectra. For example, 1 exists in an equilibrium of five adenine-containing species when dissolved in D 2O, 2 undergoes dissociation to [Pt(NH 3) 3(9-MeA-N7)] 2+ or forms the migration product [(dien)Pd(N6-9-MeA --N7)Pt(NH 3) 3] 3+ (2a), depending on pD, and 4 loses both (trpy)Pd II entities as the pD is increased. In no case is Pd binding to N3 of the adenine ring observed. A comparison of the solid-state structures of the two trinuclear complexes 1 and 4 reveals distinct differences between the Pd atoms bonded to N1 and N6 in that these are substantially out of the nucleobase plane in 1, by ca. 0.6 Ã… and -1.0 Ã…, respectively, whereas they are coplanar with the 9-MeA - plane in 4. These out-of-plane movements of the two (dien)Pd II units in 1 are not accompanied by changes in hybridization states of the N1 and N6 atoms. © 2012 American Chemical Society.This work is supported by the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie, and the TU Dortmund. P.J.S.M. thanks the Spanish Ministerio de Economía y Competitividad for funding through the “Ramón y Cajal” program.Peer Reviewe

Acid-base and metal ion binding properties of 2-thiocytidine in aqueous solution

The thionucleoside 2-thiocytidine (C2S) occurs in nature in transfer RNAs; it receives attention in diverse fields like drug research and nanotechnology. By potentiometric pH titrations we measured the acidity constants of H(C2S)(+) and the stability constants of the M(C2S)(2+) and M(C2S-H)(+) complexes (M2+ = Zn2+ , Cd2+), and we compared these results with those obtained previously for its parent nucleoside, cytidine (Cyd). Replacement of the (C2)=O unit by (C2)=S facilitates the release of the proton from (N3)H+ in H(C2S)(+) (pK (a) = 3.44) somewhat, compared with H(Cyd)(+) (pK (a) = 4.24). This moderate effect of about 0.8 pK units contrasts with the strong acidification of about 4 pK units of the (C4)NH2 group in C2S (pK (a) = 12.65) compared with Cyd (pK (a) approximate to 16.7); the reason for this result is that the amino-thione tautomer, which dominates for the neutral C2S molecule, is transformed upon deprotonation into the imino-thioate form with the negative charge largely located on the sulfur. In the M(C2S)(2+) complexes the (C2)S group is the primary binding site rather than N3 as is the case in the M(Cyd)(2+) complexes, though owing to chelate formation N3 is to some extent still involved in metal ion binding. Similarly, in the Zn(C2S-H)(+) and Cd(C2S-H)(+) complexes the main metal ion binding site is the (C2)S- unit (formation degree above 99.99 chelate formation with N3 must be surmised for the M(C2S-H)(+) species in accord with previous solid-state studies of related ligands. Upon metal ion binding, the deprotonation of the (C4)NH2 group (pK(a) = 12.65) is dramatically acidified (pK (a) approximate to 3), confirming the very high stability of the M(C2S-H)(+) complexes. To conclude, the hydrogen-bonding and metal ion complex forming capabilities of C2S differ strongly from those of its parent Cyd; this must have consequences for the properties of those RNAs which contain this thionucleoside