Synthesis of 1H-1,2,3-Triazole-Linked Quinoline-Isatin Molecular Hybrids as Anti-Breast Cancer and Anti-Methicillin-Resistant Staphylococcus aureus (MRSA) Agents.

BACKGROUND: The persistence of breast cancer as the leading cause of mortality among women, coupled with drug resistance to tamoxifen, the standard endocrine therapy for the disease, exacts continuous attention. To this effect, molecular hybridisation offers an attractive route to drugs with improved bioactivity profiles. OBJECTIVE: The primary goal of this study was to examine the potential of 1H-1,2,3-triazole linked quinolineisatin molecular hybrids as drug candidates against breast cancer and Methicillin-Resistant Staphylococcus aureus (MRSA) cells. METHODS: The quinoline-isatin hybrids were synthesised via click chemistry-mediated molecular hybridisation strategy. Anti-breast cancer activity was determined in 3-(4,5-dimethylthiazol-z-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using Estrogen-Responsive (ER+) MCF-7 and MDA-MB-231 (Triple-Negative Breast Cancer -TNBC) cells, while antimicrobial efficacy was established via the broth dilution method. Also, the toxicity profile of potent compounds to non-cancerous cells was determined using human embryonic kidney cells (HEK293) and human Red Blood Cells (hRBCs). In silico techniques were employed to predict the druglike properties of potent compounds and understand their binding modes with Estrogen Receptor alpha (ERα). RESULTS: Compounds 7g-i exhibited the strongest cytotoxicity to MCF-7 cells with IC50 values of 23.54, 23.66, and 32.50µM, respectively. Interestingly, compound 7h also emerged as the best drug candidate against MDAMB- 231 and MRSA cells with IC50=71.40µM and MIC80=27.34µM, respectively. Structure-activity relationship analysis revealed that quinoline-2-carbaldehyde and 5,7-disubstituted isatin moieties confer desirable potency. These compounds showed no significant cytotoxic or haemolytic effects on HEK293 or hRBCs in vitro at their active concentrations; hence, eliciting their selectivity for cancer cells. In silico studies also presented the drugability of potent compounds and the likely structural features interacting with amino acid residues at the ligandbinding domain of ERα. CONCLUSION: These results suggest that the identified 1H-1,2,3-triazole-linked quinoline-isatin hybrids are viable chemotypes that can be adopted as templates for the development of new anti-breast cancer and anti-MRSA agents.

Synthesis of indole-tethered [1,3,4]thiadiazolo and [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids as anti-pancreatic cancer agents.

New indole-tethered [1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one (8a-j) and [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids (9a-e) were synthesized using [4+2] cycloaddition reactions of functionalized 1,3-diazabuta-1,3-dienes with indole-ketenes. All molecular hybrids were structurally characterized by spectroscopic techniques (IR, NMR, and HRMS) and screened for their anti-pancreatic cancer activity in vitro. The [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids (9a-e) showed stronger anti-pancreatic cancer activity than the [1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one hybrids (8a-j) against the PANC-1 cell line. Compound 9d bearing an ortho-chlorophenyl moiety emerged as the most potent anti-pancreatic cancer agent with an IC50 value of 7.7 ± 0.4 µM, much superior to the standard drug Gemcitabine (IC50 > 500 µM). The discovery of these [1,3,4]thiadiazolo and [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids elicits their potentials as pursuable candidates for pancreatic cancer chemotherapy.

Therapeutic significance of ß-glucuronidase activity and its inhibitors: A review.

The emergence of disease and dearth of effective pharmacological agents on most therapeutic fronts, constitutes a major threat to global public health and man's existence. Consequently, this has created an exigency in the search for new drugs with improved clinical utility or means of potentiating available ones. To this end, accumulating empirical evidence supports molecular target therapy as a plausible egress and, ß-glucuronidase (ßGLU) - a lysosomal acid hydrolase responsible for the catalytic deconjugation of ß-d-glucuronides has emerged as a viable molecular target for several therapeutic applications. The enzyme's activity level in body fluids is also deemed a potential biomarker for the diagnosis of some pathological conditions. Moreover, due to its role in colon carcinogenesis and certain drug-induced dose-limiting toxicities, the development of potent inhibitors of ßGLU in human intestinal microbiota has aroused increased attention over the years. Nevertheless, although our literature survey revealed both natural products and synthetic scaffolds as potential inhibitors of the enzyme, only few of these have found clinical utility, albeit with moderate to poor pharmacokinetic profile. Hence, in this review we present a compendium of exploits in the present millennium directed towards the inhibition of ßGLU. The aim is to proffer a platform on which new scaffolds can be modelled for improved ßGLU inhibitory potency and the development of new therapeutic agents in consequential.

Synthesis, computational studies and antiproliferative activities of coumarin-tagged 1,3,4-oxadiazole conjugates against MDA-MB-231 and MCF-7 human breast cancer cells.

A novel library of coumarin tagged 1,3,4 oxadiazole conjugates was synthesized and evaluated for their antiproliferative activities against MDA-MB-231 and MCF-7 breast cancer cell lines. The evaluation studies revealed that compound 9d was the most potent molecule with an IC50 value of <5 µM against the MCF-7 cell line. Interestingly, compounds 10b and 11a showed a similar trend with lower inhibitory concentration (IC50 = 7.07 µM), in Estrogen Negative (ER-) cells than Estrogen Positive (ER+) cells. Structure-activity relationship (SAR) studies revealed that conjugates bearing benzyl moieties (9b, 9c and 9d) had superior activities compared to their alkyl analogues. The most potent compound 9d showed ∼1.4 times more potent activity than tamoxifen against MCF-7 cell line; while the introduction of sulfone unit in compounds 11a, 11b and 11c resulted in significant cytotoxicity against both MCF-7 and MDA-MB-231 cell lines. These results were further supported by docking studies, which revealed that the stronger binding affinity of the synthesized conjugates is due to the presence of sulfone unit attached to the substituted benzyl moiety in their pharmacophores.

Current anti-diabetic agents and their molecular targets: A review.

Diabetes mellitus is a medical condition characterized by the body's loss of control over blood sugar. The frequency of diagnosed cases and consequential increases in medical costs makes it a rapidly growing chronic disease that threatens human health worldwide. In addition, its unnerving statistical projections are perilous to both the economy of the nation and man's life expectancy. Type-I and type-II diabetes are the two clinical forms of diabetes mellitus. Type-II diabetes mellitus (T2DM) is illustrated by the abnormality of glucose homeostasis in the body, resulting in hyperglycemia. Although significant research attention has been devoted to the development of diabetes regimens, which demonstrates success in lowering blood glucose levels, their efficacies are unsustainable due to undesirable side effects such as weight gain and hypoglycemia. Over the years, heterocyclic scaffolds have been the basis of anti-diabetic chemotherapies; hence, in this review we consolidate the use of bioactive scaffolds, which have been evaluated for their biological response as inhibitors against their respective anti-diabetic molecular targets over the past five years (2012-2017). Our investigation reveals a diverse target set which includes; protein tyrosine phosphatase 1 B (PTP1B), dipeptidly peptidase-4 (DPP-4), free fatty acid receptors 1 (FFAR1), G protein-coupled receptors (GPCR), peroxisome proliferator activated receptor-γ (PPARγ), sodium glucose co-transporter-2 (SGLT2), α-glucosidase, aldose reductase, glycogen phosphorylase (GP), fructose-1,6-bisphosphatase (FBPase), glucagon receptor (GCGr) and phosphoenolpyruvate carboxykinase (PEPCK). This review offers a medium on which future drug design and development toward diabetes management may be modelled (i.e. optimization via structural derivatization), as many of the drug candidates highlighted show promise as an effective anti-diabetic chemotherapy.

Recent advances (2015-2016) in anticancer hybrids.

In spite of the development of a large number of novel anticancer drugs over the years, Cancer remains as a prominent cause of death, worldwide. Numerous drugs that are currently in clinical practice have developed multidrug resistance along with fatal side effects. Therefore, the utilization of single-target therapy is incapable of providing an effective control on the malignant process. Molecular hybridization, involving a combination of two or more pharmacophores of bioactive scaffolds to generate a single molecular architecture with improved affinity and activity, in comparison to their parent molecules, has emerged as a promising strategy in recent drug discovery research. Hybrid anticancer drugs are of great therapeutic interests since they can potentially overcome most of the pharmacokinetic drawbacks encountered with conventional anticancer drugs. Strategically, the design of anticancer drugs involved the blending or linking of an anticancer drug with another anticancer drug or a carrier molecule which can efficiently target cancer cells with improved biological potential. Major advantages of hybrid anticancer drugs involved increased specificity, better patient compliance, and lower side effects along with reduction in chemo-resistance. The successful utilization of this technique in design and synthesis of novel anticancer hybrids has been well illustrated and documented in the literature. The purpose of the present review article will be to provide an emphasis on the recent developments (2015-16) in anticancer hybrids with insights into their structure-activity relationship (SAR) and mechanism of action.