Identification of four ene reductases and their preliminary exploration in the asymmetric synthesis of (R)-dihydrocarvone and (R)-profen derivatives

The ene reductases (ERs) from the old yellow enzymes (OYEs) family have the ability to reduce activated alkenes to generate up to two stereocenters, therefore they have been received extensive attention as powerful biocatalysts. In this study, through gene mining, four ERs were identified from the genomes of Ensifer adhaerens, Pseudomonas fluorescens, and Pseudomonas veronil. The biocatalytic properties of these four ERs were identified, and their applications in the synthesis process of dihydrocarvone and profen derivatives were further evaluated. Among them, three ERs (EaER2, PvER1, and PvER2) belonging to the classic OYEs showed the best catalytic activity at 30 °C and pH 7.0 (100 mM potassium phosphate buffer) and the PfER2, which belongs to the thermophilic-like OYEs exhibited the best catalytic at 40 °C and pH 7.0 (100 mM potassium phosphate buffer). When exploring the influence of organic solvents on the catalytic efficiency, it was found that the four ERs were more sensitive to toluene and had tolerance to several other selected organic solvents. In addition, EaER2, PfER2, PvER1 and PvER2 showed excellent catalytic activity toward carvone, and the stereoselectivity of PvER2 toward carvone could reach up to 88.7 % de. EaER2 and PfER2 can catalyze the synthesis of a variety of profen derivatives with a stereoselectivity over 99 % ee. Moreover, through homology modeling and molecular docking, we preliminarily explained the mechanism of catalytic activity and stereoselectivity of the four ERs, which provided a solid base on the rational design of their stereo-preference in the future. The discovery of EaER2, PfER2, PvER1, and PvER2 provides four new enzyme sources for the study of the OYEs family and enriches the biocatalytic toolbox of ERs. Our exploration of the enzymatic properties of these four ERs will provide the sufficient data basis for future research and industrialization progress.

Arylpropionic acid-derived NSAIDs: New insights on derivatization, anticancer activity and potential mechanism of action

NSAIDs displayed chemopreventive and anticancer effects against several types of cancers. Moreover, combination of NSAIDs with anticancer agents resulted in enhanced anticancer activity. These findings have attracted much attention of researchers working in this field. The 2-arylpropionic acid-derived NSAIDs represent one of the most widely used anti-inflammatory agents. Additionally, they displayed antiproliferative activities against different types of cancer cells. Large volume of research was performed to identify molecular targets responsible for this activity. However, the exact mechanism underlying the anticancer activity of profens is still unclear. In this review article, the anticancer potential, structure activity relationship and synthesis of selected profen derivatives were summarized. This review is focused also on non-COX targets which can mediate the anticancer activity of this derivatives. The data in this review highlighted profens as promising lead compounds in future research to develop potent and safe anticancer agents.

Facile synthesis of magnetic carbon nanotubes derived from ZIF-67 and application to magnetic solid-phase extraction of profens from human serum

Magnetic carbon nanotubes (CNTs) with encapsulated Co nanoparticles (Co@CNTs), was synthesized by exploiting the one-step pyrolysis strategy using ZIF-67 as template. The as-synthesized Co@CNTs is provided with the nanopores, a large specific surface area, and strong magnetic response. The obtained Co@CNTs was used as magnetic solid-phase extraction adsorbents to extract two profens including flurbiprofen and ketoprofen. The parameters of extraction efficiency, involving extraction time, sample solution volume, ionic strength, pH and the conditions of desorption efficiency, were optimized in detail. After determined by high-performance liquid chromatography-ultraviolet (HPLC-UV), the results evinced that Co@CNTs showed a high extraction efficiency with high enrichment factors of 832 and 672. The good linear range of both flurbiprofen and ketoprofen were all 5.0-1000 ng L^-1, with the limit of detection were 0.60 ng L^-1 and 0.70 ng L^-1, respectively. Furthermore, a valid method for the extraction of flurbiprofen and ketoprofen from human serum was established. The spiking recoveries of two profens were between 86.74% and 97.22%, and the relative standard deviation was less than 6.55%. Co@CNTs can be repeatedly used at least 10 times, indicating its excellent regeneration and reusability. The results demonstrated that the Co@CNTs materials exhibits high enrichment ability and extraction efficiency, playing great promise in MSPE.

A small diversity library of α-methyl amide analogs of sulindac for probing anticancer structure-activity relationships

Non-steroidal anti-inflammatory drugs (NSAIDs) have a variety of potential indications that include management of pain and inflammation as well as chemoprevention and/or treatment of cancer. Furthermore, a specific form of ibuprofen, dexibuprofen or the S-(+) form, shows interesting neurological activities and has been proposed for the treatment of Alzheimer's disease. In a continuation of our work probing the anticancer activity of small sulindac libraries, we have prepared and screened a small diversity library of α-methyl substituted sulindac amides in the profen class. Several compounds of this series displayed promising activity compared with a lead sulindac analog.

Marginally designed new profen analogues have the potential to inhibit cyclooxygenase enzymes

The current structure-activity relationship of profens (i.e., 2-arylpropionic acid derivatives, a class of non-steroidal anti-inflammatory drugs) discusses the importance of α-monomethyl substitution on these compounds, since the activities obtained through their corresponding arylacetic acid derivatives (i.e., α-demethylated derivatives) or α,α-dimethyl-substituted compounds are less than what is observed for the parent profens. Unfortunately, this implies a generalization in structure-activity relationships of profens in such a way that a mono-(non-methyl)alkyl group or dialkyl substituent replaced at the α-position of a profen analogue results in abolished activity. Therefore, within this study, we aimed to question this generalization employing ibuprofen, flurbiprofen, and naproxen as model compounds. A series of α-(non-methyl)alkyl-substituted ibuprofen and flurbiprofen analogues as well as α,α-dialkyl-substituted ibuprofen, flurbiprofen, and naproxen derivatives were synthesized and screened for their potential to inhibit cyclooxygenase enzymes. In addition, since profens have negligible potential to inhibit lipoxygenase enzymes, the effect of such derivatization was also questioned in lipoxygenase inhibition assays. The findings only partially agreed with the current structure-activity approach of profens and the activity results of some compounds were found as beyond ordinary.