Synthesis and antimicrobial activities of 2-azetidinyl-4-quinazolinone derivatives of diclofenac analogue

Green alga Chlamydomonas reinhardtii can effectively remove diclofenac from the water environment - A new perspective on biotransformation

The use of unicellular algae to remove xenobiotics (including drugs) from wastewaters is one of the rapidly developing areas of environmental protection. Numerous data indicate that for efficient phycoremediation three processes are important, i.e. biosorption, bioaccumulation, and biotransformation. Although biosorption and bioaccumulation do not raise any serious doubts, biotransformation is more problematic since its products can be potentially more toxic than the parent compounds posing a threat to organisms living in a given environment, including organisms that made this transformation. Thus, two questions need to be answered before the proper algae strain is chosen for phycoremediation, namely what metabolites are produced during biotransformation, and how resistant is the analyzed strain to a mixture of parent compound and metabolites that appear over the course of culture? In this work, we evaluated the remediation potential of the model green alga Chlamydomonas reinhardtii in relation to non-steroidal anti-inflammatory drugs (NSAIDs), as exemplified by diclofenac. To achieve this, we analysed the susceptibility of C. reinhardtii to diclofenac as well as its capability to biosorption, bioaccumulation, and biotransformation of the drug. We have found that even at a relatively high concentration of diclofenac the algae maintained their vitality and were able to remove (37.7%) DCF from the environment. A wide range of phase I and II metabolites of diclofenac (38 transformation products) was discovered, with many of them characteristic rather for animal and bacterial biochemical pathways than for plant metabolism. Due to such a large number of detected products, 18 of which were not previously reported, the proposed scheme of diclofenac transformation by C. reinhardtii not only significantly contributes to broadening the knowledge in this field, but also allows to suggest possible pathways of degradation of xenobiotics with a similar structure. It is worth pointing out that a decrease in the level of diclofenac in the media observed in this study cannot be fully explained by biotransformation (8.4%). The mass balance analysis indicates that other processes (total 22%), such as biosorption, a non-extractable residue formation, or complete decomposition in metabolic cycles can be involved in the diclofenac disappearance, and those findings open the prospects of further research.

Development of certain aminoquinazoline scaffolds as potential multitarget anticancer agents with apoptotic and anti-proliferative effects: Design, synthesis and biological evaluation

Newly designed 4 - aminoquinazoline derivatives (5a-f, 6a, b, 7, 8, 9, 10a-c, 11a, b, 12a, b and 13a, b) have been synthesized and evaluated for their potential multitarget anticancer activities, apoptotic and anti-proliferative effects. Thereupon, in vitro cytotoxic activities of all the synthesized compounds were screened against NCI 60 human cancer cell lines (nine subpanels) at NCI, USA. Successfully, 2-morpholino-N-(quinazolin-4-yl) acetohydrazide 5e was granted an NSC code, owing to its significant potency and broad spectrum of activity against various cancer cell lines; leukemia K-562, non-small cell lung cancer NCI-H522 cells, colon cancer SW-620, melanoma LOX IMVI, MALME-3M, renal cancer RXF 393, ACHN and breast cancer MDA-MB231/ATCC (GI% = 99.6, 161, 126.03, 90.22, 174.47, 139.7, 191 and 97, respectively). Compound 5e showed the best inhibitory activity (GI₅₀ = 1.3 µM) against melanoma LOX IMVI, when tested at five doses against NCI 60 cell lines. Furthermore, compound 5e showed comparable EGFR and CDK2 inhibitory activity results (IC₅₀ = 0.093 ± 0.006 μM and 0.143 ± 0.008 μM, respectively) to those of lapatinib and ribociclib (IC₅₀ = 0.03 ± 0.002 μM and 0.067 ± 0.004 μM, respectively). Western blotting analysis of compound 5e against melanoma LOX IMVI marked out significant reduced EGFR and CDK2 protein expression percentages, up to 32.97% and 34.09%, respectively, if compared to lapatinib (31.18%) and ribociclib (29.66%). Moreover, compound 5e caused clear cell cycle arrests at S phase of renal UO-31 cells and at G1 phase of both breast cancer MCF7 and ovarian cancer IGROV1, associated with remarkable increase of DNA content of the controls. In accordance, it demonstrated promising anti- proliferative and apoptotic activities, showing a significant increase in total apoptotic percentages of renal cancer UO-31, breast cancer MCF7 and ovarian IGROV1 cancer cell lines, if compared to the control untreated cells (from 1.79% to 46.72%, 2.19% to 39.02% and 1.66 to 42.51%, respectively). Molecular modelling and dynamic simulation study results supported the main objectives of the present work.

Two decades of recent advances of Ugi reactions: synthetic and pharmaceutical applications

Multicomponent reactions (MCRs) are powerful synthetic tools in which more than two starting materials couple with each other to form multi-functionalized compounds in a one-pot process, the so-called “tandem”, “domino” or “cascade” reaction, or utilizing an additional step without changing the solvent, the so-called a sequential-addition procedure, to limit the number of synthetic steps, while increasing the complexity and the molecular diversity, which are highly step-economical reactions. The Ugi reaction, one of the most common multicomponent reactions, has recently fascinated chemists with the high diversity brought by its four- or three-component-based isonitrile. The Ugi reaction has been introduced in organic synthesis as a novel, efficient and useful tool for the preparation of libraries of multifunctional peptides, natural products, and heterocyclic compounds with stereochemistry control. In this review, we highlight the recent advances of the Ugi reaction in the last two decades from 2000–2019, mainly in the synthesis of linear or cyclic peptides, heterocyclic compounds with versatile ring sizes, and natural products, as well as the enantioselective Ugi reactions. Meanwhile, the applications of these compounds in pharmaceutical trials are also discussed.

We highlight the recent advances of the Ugi reaction in the last two decades from 2000–2019, mainly in the synthesis of linear or cyclic peptides, heterocyclic compounds with versatile ring sizes, and natural products, as well as the enantioselective Ugi reactions.

The Current Case of Quinolones: Synthetic Approaches and Antibacterial Activity

Quinolones are broad-spectrum synthetic antibacterial drugs first obtained during the synthesis of chloroquine. Nalidixic acid, the prototype of quinolones, first became available for clinical consumption in 1962 and was used mainly for urinary tract infections caused by Escherichia coli and other pathogenic Gram-negative bacteria. Recently, significant work has been carried out to synthesize novel quinolone analogues with enhanced activity and potential usage for the treatment of different bacterial diseases. These novel analogues are made by substitution at different sites--the variation at the C-6 and C-8 positions gives more effective drugs. Substitution of a fluorine atom at the C-6 position produces fluroquinolones, which account for a large proportion of the quinolones in clinical use. Among others, substitution of piperazine or methylpiperazine, pyrrolidinyl and piperidinyl rings also yields effective analogues. A total of twenty six analogues are reported in this review. The targets of quinolones are two bacterial enzymes of the class II topoisomerase family, namely gyrase and topoisomerase IV. Quinolones increase the concentration of drug-enzyme-DNA cleavage complexes and convert them into cellular toxins; as a result they are bactericidal. High bioavailability, relative low toxicity and favorable pharmacokinetics have resulted in the clinical success of fluoroquinolones and quinolones. Due to these superior properties, quinolones have been extensively utilized and this increased usage has resulted in some quinolone-resistant bacterial strains. Bacteria become resistant to quinolones by three mechanisms: (1) mutation in the target site (gyrase and/or topoisomerase IV) of quinolones; (2) plasmid-mediated resistance; and (3) chromosome-mediated quinolone resistance. In plasmid-mediated resistance, the efflux of quinolones is increased along with a decrease in the interaction of the drug with gyrase (topoisomerase IV). In the case of chromosome-mediated quinolone resistance, there is a decrease in the influx of the drug into the cell.