A thin-layer chromatography-bioautographic method for detecting dipeptidyl peptidase IV inhibitors in plants

A thin-layer chromatography (TLC)-bioautographic method was developed with the aim to detect dipeptidyl peptidase IV (DPP IV) inhibitors from plant extracts. The basic principle of the method is that the enzyme (DPP IV) hydrolyzes substrate (Gly-Pro-p-nitroaniline) into p-nitroaniline (pNA), which diazotizes with sodium nitrite, and then reacts with N-(1-naphthyl) ethylenediamine dihydrochloride in turn to form a rose-red azo dye which provides a rose-red background on the TLC plates. The DPP IV inhibitors showed white spots on the background as they blocked enzymolysis of the substrate to produce pNA. The method was validated with respect to selectivity, sensitivity, linearity, precision, recovery, and stability after optimizing key parameters including plate type, time and temperature of incubation, concentration of substrate, enzyme and derivatization reagents, and absorption wavelength. The results showed good lineary within amounts over 0.01–0.1 μg range for the positive control, diprotin A, with the coefficient of determination (r2) = 0.9668. The limits of detection (LOD) and quantification (LOQ) were 5 and 10 ng, respectively. The recoveries ranged from 98.9% to 107.5%. The averages of the intra- and inter-plate reproducibility were in the range of 4.1–9.7% and 7.6–14.7%, respectively. Among the nine methanolic extracts of medicinal herbs screened for DPP IV inhibitors by the newly developed method, Peganum nigellastrum Bunge was found to have one white active spot, which was then isolated and identified as harmine. By spectrophotometric method, harmine hydrochloride was found to have DPP-IV inhibitory activity of 32.4% at 10 mM comparing to that of 54.8% at 50 μM for diprotin A.

Muslims in Public and Media Discourse in Western Europe: The Reproduction of Aporia and Exclusion

This chapter scrutinizes the dominant public discourse in Western Europe. Drawing on examples from the UK, Germany, and France but also from the Netherlands, Denmark and Spain it illustrates the gradual transformation of discourse from an “exotic Islam” to a “threatening Islam” that endangers European values and safety and suggests that the combination of this “securitization” of Islam and the monopoly of the “Muslim voice” by radical Muslim activists leads to a vicious circle of misrecognition and enhancing the aporia of Europe's Muslims.

Rights, Rationality and Reproduction: Balancing Interests in the Abortion Debate

As medical technology has advanced, so too have our attitudes towards the level of control we can or should expect to have over our procreative capacities. This creates a multidimensional problem for the law and family planning services in terms of access to services – whether to avoid conception or terminate a pregnancy – and the negligent provision of these services. These developments go to the heart of our perception of autonomy. Unsurprisingly, these matters also raise a moral dilemma for the law. Distinctively, discourse in this area is dominated by assertions of subjective moral value; in relation to life, to personal choice and to notions of the archetypal family. Against this, I stress that a model of objective morality can answer these challenging questions and resolve the inherent problems of legal regulation. Therefore, I argue that notions of autonomy must be based on a rational, action-based understanding of what it means to be a ‘moral agent’. I claim that from this we might support a legal standard, based on objective rational morality, which can frame our constitutional norms and our conception of justice in these contentious areas. This paper claims that the current regulation of abortion is outdated and requires radical reform. It proposes a scheme that would shift the choice towards the mother (and the father), remove the unnecessarily broad disability ground and involve doctors having a role of counsel (rather than gatekeeper).