Sustainable Phenylalanine-Derived SAILs for Solubilization of Polycyclic Aromatic Hydrocarbons.

The solubilization capacity of a series of sustainable phenylalanine-derived surface-active ionic liquids (SAILs) was evaluated towards polycyclic aromatic hydrocarbons-naphthalene, anthracene and pyrene. The key physico-chemical parameters of the studied systems (critical micelle concentration, spectral properties, solubilization parameters) were determined, analyzed and compared with conventional cationic surfactant, CTABr. For all studied PAH solubilization capacity increases with extension of alkyl chain length of PyPheOCn SAILs reaching the values comparable to CTABr for SAILs with n = 10-12. A remarkable advantage of the phenylalanine-derived SAILs PyPheOCn and PyPheNHCn is a possibility to cleave enzymatically ester and/or amide bonds under mild conditions, to separate polycyclic aromatic hydrocarbons in situ. A series of immobilized enzymes was tested to determine the most suitable candidates for tunable decomposition of SAILs. The decomposition pathway could be adjusted depending on the choice of the enzyme system, reaction conditions, and selection of SAILs type. The evaluated systems can provide selective cleavage of the ester and amide bond and help to choose the optimal decomposition method of SAILs for enzymatic recycling of SAILs transformation products or as a pretreatment towards biological mineralization. The concept of a possible practical application of studied systems for PAHs solubilization/separation was also discussed focusing on sustainability and a green chemistry approach.

Antidepressant drug-protein interactions studied by spectroscopic methods based on fluorescent carbon quantum dots.

A highly sensitive fluorescent carbon quantum dots (CDs) was designed to measure the interaction of antidepressant drugs and serum albumins (SA). In present investigation the interaction of bovine serum albumin (BSA) and human serum albumin (HSA) with antidepressant drugs viz. amitryptiline hydrochloride (AMT), chlorpromazine hydrochloride (CPZ) and desipramine hydrochloride (DSP) bioconjugated on CDs have been studied by different spectroscopic techniques i.e., Fluorescence, UV-Visible, Dynamic light scattering (DLS) and FT-IR. The CDs were prepared by one-pot method using glucose and PEG-200. The developed CDs showed blue luminescence under irradiation with ultra-violet. The Stern-Volmer quenching constant (K sv ) indicates the presence of static quenching mechanism. The apparent binding constant K a between antidepressant drugs with complex of SA-CDs have been determined. These results illustrated that CPZ shows strong binding with HSA. As further analyzed by FT-IR spectroscopy and DLS technique, the results suggested induced conformational changes on SA, thus confirming the experimental and theoretical results. Thus, a thorough knowledge of the energetics of drug-protein affinities in presence of CDs as attempted in this work is vital in giving way for appropriate drug delivery.