Dietary intake of antioxidants has been associated with a reduced risk of cardiovascular diseases, which is very likely caused by their capability of prevent oxidation of low-density lipoproteins (LDL). During food processing and storage, substances with antioxidative properties are formed by Maillard reactions. In this study, the activity of Maillard products to inhibit copper-induced oxidation of human LDL in vitro was investigated. d-Glucose was heated with an equimolar amount of glycine, l-lysine, or l-arginine, for 1 h under reflux. The increase of the antioxidative activity (AOA) of the Maillard mixtures was highly significant compared to the control mixtures. Additionally, two defined Maillard products with amino reductone structure were tested. 3-Hydroxy-4-(morpholino)-3-buten-2-one (1) and amino hexose reductone (2) showed a significant and dose dependent AOA. Compound 1 was about half as active as ascorbic acid, which served as positive control. Thus, it can be concluded that Maillard products, particularly those with amino reductone structure, have the strong potential to inhibit LDL oxidation.

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Males can increase their reproductive success by mechanically hindering females to mate with subsequent males. Research on mating plugs so far has focused on the fitness consequences and demonstrated that plug size can strongly determine its efficacy. Here, we explore: (1) the site of plug production in the erigonine spider Oedothorax retusus; and (2) whether males are limited in the production of plug material when mating with three females in succession. Micro‐computed tomography, histological and ultrastructural sections demonstrate that the plug material is produced in a massive gland inside the sperm transfer organs of the male, the pedipalps. The glandular lumen is connected with the tube‐like spermophore almost at its blind end. Probably, a reservoir of plug material is built up at the end of the spermophore and released after sperm transfer onto the female genital opening. Since not all males applied a large plug during their first mating, there was no significant decline in plug size over the course of the three successive matings. However, the size of the first plug significantly affected the size of the following plug. We discuss these findings in the light of plug limitation and mate choice. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 345–354.

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