6-(N-[3-Maleimidopropionamido])hexanoate-succinimide

Objective:The aim of this systematic review and meta-analysis was to examine the association between high ratio of n-6/n-3 polyunsaturated fatty acids (PUFAs) and depression. Methods:The authors conducted a meta-analysis of research articles on the association of high ratio of n-6/n-3 PUFAs with the risk of depression published in the online article database on PubMed, Embase, Cochrane library as of December 2021. Pooled odds ratios (OR) were calculated using random effects models. Publication bias was assessed visually by funnel plots and statistically by the Egger's and Begg's tests. Results:Finally, 12 studies included in this systematic review and meta-analysis with a total of 66,317 participants (including 4,173 individuals with depression condition). The pooled results showed that high ratio of n-6/n-3 PUFAs might be positively associated with depression [OR = 1.21, 95% confidence intervals (CIs): 1.04~1.41]. The I2 test indicated that there was a substantial statistical heterogeneity across the included studies (I 2 = 54.38%, P = 0.01). Subgroup analysis showed that high ratio of n-6/n-3 PUFAs in blood had no significant association with depression (OR = 1.15, 95%CI: 0.88~1.50), while high ratio of n-6/n-3 PUFAs in dietary supplements was positively associated with depression (OR = 1.32, 95%CI: 1.16~1.51).Conclusion:This meta-analysis confirmed the association between high ratio of n-6/n-3 PUFAs and the risk of depression. High ratio of n-6/n-3 PUFAs in dietary supplementation was positively associated with depression, but had no significant association in the blood. This study suggested that lowering the dietary intake of the ratio of n-6/n-3 PUFAs would be beneficial in the prevention of depression.

Polyunsaturated fatty acids (PUFAs) contain ≥2 double-bond desaturations within the acyl chain. Omega-3 (n-3) and Omega-6 (n-6) PUFAs are the two known important families in human health and nutrition. In both Omega families, many forms of PUFAs exist: α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) from the n-3 family and linoleic acid (LA), dihomo-γ-linolenic acid (DGLA), and arachidonic acid (AA) from the n-6 family are the important PUFAs for human health. Omega-3 and Omega-6 PUFAs are competitively metabolized by the same set of desaturation, elongation, and oxygenase enzymes. The lipid mediators produced from their oxidative metabolism perform opposing (antagonistic) functions in the human body. Except for DGLA, n-6 PUFA-derived lipid mediators enhance inflammation, platelet aggregation, and vasoconstriction, while those of n-3 inhibit inflammation and platelet aggregation and enhance vasodilation. Overconsumption of n-6 PUFAs with low intake of n-3 PUFAs is highly associated with the pathogenesis of many modern diet-related chronic diseases. The volume of n-6 PUFAs is largely exceeding the volume of n-3PUFAs. The current n-6/n-3 ratio is 20-50/1. Due to higher ratios of n-6/n-3 in modern diets, larger quantities of LA- and AA-derived lipid mediators are produced, becoming the main causes of the formation of thrombus and atheroma, the allergic and inflammatory disorders, and the proliferation of cells, as well as the hyperactive endocannabinoid system. Therefore, in order to reduce all of these risks which are due to overconsumption of n-6 PUFAs, individuals are required to take both PUFAs in the highly recommended n-6/n-3 ratio which is 4-5/1.

The delocalized π-conjugated units are considered as an advantageous gene for improving the optical nonlinearity of acentric crystals. For the first time, we synthesized a new acentric SHG-active metal cyamelurate crystal K3C6N7O3·2H2O (I) by a facile solution method, containing a colossal planar π-conjugated (C6N7O3)3- unit. It displays a strong second-order harmonic generation (SHG) of 4 × KDP and a giant anisotropic birefringence of 0.446 at 1064 nm. The theoretical calculations reveal that such substantial improvement is contributed from the strong molecular susceptibility of (C6N7O3)3- units and their near-perfect coplanar arrangement. Moreover, I exhibits a broadband ultraviolet photoluminescence at 366 nm, suggesting its multifunctional capacity and great potential for compact highly integrated optoelectronic devices.