Design, molecular modeling and anticancer evaluation of thieno[2,3-d]pyrimidine derivatives as inhibitors of topoisomerase II

A decade's overview of 2-aminothiophenes and their fused analogs as promising anticancer agents

Over the past decades, cancer has been a challenging domain for medicinal chemists as it is an international health concern. In association, small molecules such as 2-aminothiophenes and their derivatives showed significant antitumor activity through variable modes of action. Therefore, this article aims to review the advances regarding these core scaffolds over the past 10 years, where 2-aminothiophenes and their fused analogs are classified and discussed according to their biological activity and mode of action, in the interest of boosting new design pathways for medicinal chemists to develop targeted antitumor candidates.

Exploring the Antiproliferative Potency of Pyrido[2,3-d]Pyrimidine Derivatives: Studies on Design, Synthesis, Anticancer Evaluation, SAR, Docking, and DFT Calculations

Herein, an efficient method for the synthesis of a new series of pyrido[2,3-d]pyrimidine derivatives has been adopted through the reaction of hydrazinyl pyrido[2,3-d] pyrimidine derivative (1) with different electrophilic species, such as ethyl cyanoacetate and different 1,3 diketone derivatives, gave the corresponding derivatives (2-5). Meanwhile, pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidines (6-11) were synthesized via reaction of hydrazine derivative 1 with phenylisothiocyanate, potassium thiocyanate, and carbon disulfide. Compound 1 was also submitted to react with different carbonyl compounds to afford pyrido-pyrimidine derivatives (12-15). All the newly synthesized compounds were tested in vitro for their antiproliferative activities against HCT-116 and MCF-7 cell lines. Compounds 2, 3, 7, and 8 displayed very strong inhibitory activity against the two cell lines compared with the standard drug doxorubicin. Furthermore, a docking study of the most active compounds was performed with the thymidylate synthase enzyme (PDB: Code 6qxg). Moreover, DFT calculation was carried out for the most biologically active compounds and a reference drug (Doxorubicin) using the B3LYP/6-31G+(d,p) level of theory. The calculated EHOMO and ELUMO energies were used to calculate the global reactivity parameters. Finally, Molecular electrostatic potential (MEP) and structure activity relationship (SAR) were studied to correlate the relation between chemical structure and reactivity.

Azafuramidines as potential anticancer Agents: Pro-apoptotic profile and cell cycle arrest

The current study aimed to test the antiproliferative activity of three azafuramidines (X, Y, and Z) against three different human cell lines; liver HepG2, breast MCF-7, and bone U2OS. And to explore the molecular mechanism(s) of the antiproliferative activity of these derivatives. The three new azafuramidines demonstrated a potent cytotoxicity at < 2 μM against the three cell lines investigated. The azafuramidines were highly selective with selectivity index ∼ 47 - 61 folds indicating safety to the normal cells. In the scratch assay, azafuramidines significantly reduced the percentage of wound healing indicating ability to prevent or reduce metastasis. Derivatives X and Z arrested the HepG2 cells at S and G2/M phases detected by the flow cytometry. Derivatives X, Y, and Z elevated the apoptosis of HepG2 cells by ∼ 71 %, 66 %, and 59 %, respectively. Derivatives X and Z were superior to derivative Y. The potent antiproliferative, cell cycle arrest, and pro-apoptotic efficacy of these chlorophenyl derivatives could be attributed to their ability of inducing the overexpression of p53, p21, and p27. These derivatives had the potential to act as anticancer agents and merit further investigations.

Design and synthesis of new spirooxindole candidates and their selenium nanoparticles as potential dual Topo I/II inhibitors, DNA intercalators, and apoptotic inducers

A new wave of dual Topo I/II inhibitors was designed and synthesised via the hybridisation of spirooxindoles and pyrimidines. In situ selenium nanoparticles (SeNPs) for some derivatives were synthesised. The targets and the SeNP derivatives were examined for their cytotoxicity towards five cancer cell lines. The inhibitory potencies of the best members against Topo I and Topo II were also assayed besides their DNA intercalation abilities. Compound 7d NPs exhibited the best inhibition against Topo I and Topo II enzymes with IC50 of 0.042 and 1.172 μM, respectively. The ability of compound 7d NPs to arrest the cell cycle and induce apoptosis was investigated. It arrested the cell cycle in the A549 cell at the S phase and prompted apoptosis by 41.02% vs. 23.81% in the control. In silico studies were then performed to study the possible binding interactions between the designed members and the target proteins.

Design, synthesis, anti-proliferative evaluation, docking, and MD simulation studies of new thieno[2,3-d]pyrimidines targeting VEGFR-2

In this work, new thieno[2,3-d]pyrimidine-derived compounds possessing potential anticancer activities were designed and synthesized to target VEGFR-2. The thieno[2,3-d]pyrimidine derivatives were tested in vitro for their abilities to inhibit VEGFR-2 and to prevent cancer cell growth in two types of cancer cells, MCF-7 and HepG2. Compound 18 exhibited the strongest anti-VEGFR-2 potential with an IC50 value of 0.084 μM. Additionally, it displayed excellent proliferative effects against MCF-7 and HepG2 cancer cell lines, with IC50 values of 10.17 μM and 24.47 μM, respectively. Further studies revealed that compound 18 induced cell cycle arrest in G2/M phase and promoted apoptosis in MCF-7 cancer cells. Apoptosis was stimulated by compound 18 by increasing BAX (3.6-fold) and decreasing Bcl-2 (3.1-fold). Additionally, compound 18 significantly raised the levels of caspase-8 (2.6-fold) and caspase-9 (5.4-fold). Computational techniques were also used to investigate the VEGFR-2-18 complex at a molecular level. Molecular docking and molecular dynamics simulations were performed to assess the structural and energetic features of the complex. The protein-ligand interaction profiler analysis identified the 3D interactions and binding conformation of the VEGFR-2-18 complex. Essential dynamics (ED) study utilizing principal component analysis (PCA) described the protein dynamics of the VEGFR-2-18 complex at various spatial scales. Bi-dimensional projection analysis confirmed the proper binding of the VEGFR-2-18 complex. In addition, the DFT studies provided insights into the structural and electronic properties of compound 18. Finally, computational ADMET and toxicity studies were conducted to evaluate the potential of the thieno[2,3-d]pyrimidine derivatives for drug development. The results of the study suggested that compound 18 could be a promising anticancer agent that may provide effective treatment options for cancer patients. Furthermore, the computational techniques used in this research provided valuable insights into the molecular interactions of the VEGFR-2-18 complex, which may guide future drug design efforts. Overall, this study highlights the potential of thieno[2,3-d]pyrimidine derivatives as a new class of anticancer agents and provides a foundation for further research in this area.

New 1,3,4-thiadiazoles as potential anticancer agents: pro-apoptotic, cell cycle arrest, molecular modelling, and ADMET profile

A series of novel 1,3,4-thiadiazoles was synthesized via the reaction of N-(5-(2-cyanoacetamido)-1,3,4-thiadiazol-2-yl)benzamide (3) with different carbon electrophiles and evaluated as potential anticancer agents. The chemical structures of these derivatives were fully elucidated using various spectral and elemental analyses. Out of 24 new thiadiazoles, derivatives 4, 6b, 7a, 7d, and 19 have significant antiproliferative activity. However, derivatives 4, 7a, and 7d were toxic to the normal fibroblasts, and therefore were excluded from further investigations. Derivatives 6b and 19 with IC50 at less than 10 μM and with high selectivity were selected for further studies in breast cells (MCF-7). Derivative 19 arrested the breast cells at G2/M probably through inhibition of CDK1, while 6b significantly increased the sub-G1 percent of cells probably through induction of necrosis. These results were confirmed by the annexin V-PI assay where 6b did not induce apoptosis and increased the necrotic cells to 12.5%, and compound 19 significantly increased the early apoptosis to 15% and increased the necrotic cells to 15%. Molecular docking showed that compound 19 was like FB8, an inhibitor of CDK1, in binding the CDK1 pocket. Therefore, compound 19 could be a potential CDK1 inhibitor. Derivatives 6b and 19 did not violate Lipinski's rule of five. In silico studies showed that these derivatives have a low blood-brain barrier penetration capability and high intestinal absorption. Taken together, derivatives 6b and 19 could serve as potential anticancer agents and merit further investigations.

Recent updates on thienopyrimidine derivatives as anticancer agents

Thienopyrimidine derivatives hold a unique place between fused pyrimidine compounds. They are important and widely represented in medicinal chemistry as they are structural analogs of purines. Thienopyrimidine derivatives have various biological activities. The current review discusses different synthetic methods for the preparation of heterocyclic thienopyrimidine derivatives. It also highlights the most recent research on the anticancer effects of thienopyrimidines through the inhibition of various enzymes and pathways, which was published within the last 9 years.

Graphical Abstract

Synthesis of new thienylnicotinamidines: Proapoptotic profile and cell cycle arrest of HepG2 cells

Fourteen new thienylnicotinamidines and their analogs 5a-5k, 12, 13a, and 13b were prepared and their antiproliferative potential was evaluated against the growth of 60 cancer cell lines. The tested compounds had a strong antiproliferative efficacy against almost all cancer cell lines, with the average GI₅₀ at ~2.20 µM. The effect of the thienylnicotinamidines on the growth of normal lung fibroblast cells (WI-38) indicated that these derivatives are safe to the normal cells. The selectivity index (SI) ranges from 5.5- to 42.0-fold. The conceivable mechanisms of action of the effective compounds 5d, 5f, 5g, 5i, 5j, and 5k with high SI were investigated. Although the thienylnicotinamidines are similar in structure, they could be divided into three groups as per their effects on gene expression: The first group (5d and 5f) elevated p53 and caspase 3 expression, the second group (5g and 5i) elevated p53 expression, and the last group (5j and 5k) elevated p53 and reduced topoII expression. Many thienylnicotinamides inhibited the vascular endothelial growth factor receptor-2 (VEGFR-2) in cell lysates at concentrations comparable to or better than pazopanib. The data of caspase 3 expression were confirmed by measuring the protein level by Western blot and the activity of the cleaved active enzyme. The ability to arrest the cell cycle and induce apoptosis was confirmed by flow cytometry. Taken together, two derivatives, 5d and 5f, with a distinctive VEGFR-2 inhibitory activity and a proapoptotic and cell cycle arrest profile merit further investigations.

Bithiophene derivative induced apoptosis and suppression of Akt pathway in mouse leukemic model

BACKGROUND: Bithiophene derivatives show a promising anti-cancer potential. We previously showed that Bithienyl Fluorobenzamidine (BFB) has an anti-proliferative effect against several leukemia cell lines. Acute myeloid leukemia (AML) accounts for 18% of the total leukemia cases worldwide with heavier burden during the past 30 years. Therefore, the main aim remains the discovery of safe and effective medications. OBJECTIVE: The current research aims to investigate the anti-cancer efficacy of BFB and its effect on the apoptosis in the 7,12-Dimethylbenz[a]anthracene (DMBA) induced AML in mice. METHODS: AML was induced in mice by DMBA and then treated by 2 different doses of BFB. After BFB treatment, the hematological and histological pattern changes was examined. Furthermore, the molecular effect of BFB on apoptosis, cell cycle markers and Protein kinase B (Akt) pathway was examined using qPCR, Western blotting and ELISA. RESULTS: BFB treatment ameliorates leukemia histological and hematological markers significantly, despite non-significant changes in normal mice. This improvement exhibits cell cycle arrest and apoptosis induction, represented by elevation of tp53/p53, p21/p21, Caspase3 and downregulation of ckk1/Cdk1 in the bone marrow, as well as Akt pathway suppression. CONCLUSIONS: Our results establishes BFB as a promising therapeutic candidate against AML through cell cycle arrest, apoptosis induction and Akt pathway modulation.

New N-(1,3,4-thiadiazol-2-yl)furan-2-carboxamide derivatives as potential inhibitors of the VEGFR-2

The present study reports the synthesis and biological evaluation of a new series of novel N-(1,3,4-thiadiazol-2-yl)furan-2-carboxamide derivatives. The reactions were executed under both conventional and microwave irradiation conditions. An enhancement in the synthetic yields and rates was observed when the reactions were carried out under the microwave compared with the classical conditions. The structures of the products were ascertained by different analytical and spectral analyses. The antiproliferative activities were evaluated against three human epithelial cell lines; breast (MCF-7), colon (HCT-116), and prostate (PC-3) using MTT assay technique and doxorubicin was utilized as a reference drug. Besides, molecular docking studies were also performed and the vascular endothelial growth factor recptor-2 (VEGFR-2) was identified as a potential molecular target. Compounds 6, 7, 11a, 11b, 12, 14, and 16 showed promising antiproliferative activity against the three cancer cell lines investigated. Compounds 2 and 15b had significant antiproliferative activities against only colon and breast cells but not against the prostate cells. All the active antiproliferative compounds were highly selective. All the active antiproliferative compounds were good inhibitors of the VEGFR-2 at 7.4-11.5 nM compared with Pazopanib. Compound 7 with the most favorable orientation to the VEGFR-2 from the docking studies, was also the best inhibitor of the receptor. The antiproliferative activity of these compounds is in partial caused by their ability to inhibit the VEGFR-2 and since other molecular targets were not examined, other possibilities cannot be ruled out.

Synthesis, Antiproliferative activity, and apoptotic profile of New Derivatives from the Meta Stable Benzoxazinone Scaffold

BACKGROUND

Cancer exerts a huge strain on the health system. The emerging resistance to the current chemotherapies demands the continuous development of new anticancer agents with lower cost, higher efficacy, and greater specificity.

OBJECTIVE

Development of selective small molecules targeted anticancer agents.

METHODS

The behavior of benzoxazinone 2 towards nitrogen nucleophiles such as hydrazine hydrate, formamide, ethanolamine, aromatic amines, and thiosemcarbazide was described. The behavior of the amino quinazolinone 3 towards carbon electrophiles and P2S5 was also investigated. The antiproliferative activity of 17 new benzoxazinone derivatives was examined against the growth of three human cancer cell lines; liver HepG2, breast MCF-7, and colon HCT-29, in addition to the normal human fibroblasts WI-38 and the selectivity index was calculated. The possible molecular pathways such as the cell cycle and apoptosis were investigated.

RESULTS

Derivatives 3, 7, 8, 10, 13, and 15 had a significant (less than 10 µM) antiproliferative activity against the three cancer cell lines investigated. Derivative 7 showed the best antiproliferative profile comparable to that of doxorubicin. The selectivity index for all the effective derivatives ranged from ~5-12 folds indicating high selectivity against the cancer cells. Derivative 15 caused ~ 7-fold and 8-fold inductions in the expression of p53 and caspase3, respectively. It also caused a ~ 60% reduction in the expression of both topoisomerase II (topoII) and cyclin-dependent kinase 1 (cdk1). Derivatives 3, 7, and 8 had a similar profile; ~ 6-8-fold increases in the expression of p53 and caspase3 but these compounds were devoid of any significant effect on the expression of topoII and cdk1. Derivatives 10 and 13 were also similar and resulted in a ~6-fold elevation in the expression of caspase3, and more than 60% downregulation in the expression of topoII. The results of the gene expression of topoII and caspase 3 were confirmed by the measurement of the topoII concentration and caspase3 activity in the HepG2 cells.

CONCLUSION

Six derivatives exerted their antiproliferative activity by arresting the cell cycle (decreasing cdk1), preventing the DNA duplication (downregulating topo II), and by inducing apoptosis (inducing p53 and caspase3). One common feature in all the six active derivatives is the presence of free amino group. These compounds have merit for further investigations.

Pyrimidine: a review on anticancer activity with key emphasis on SAR

Background

Cancer is a global health challenge, it impacts the quality of life and its treatment is associated with several side effects. Resistance of the cancer cells to the existing drugs has led to search for novel anticancer agents. Pyrimidine, a privileged scaffold, is part of living organisms and plays vital role in various biological procedures as well as in cancer pathogenesis. Due to resemblance in structure with the nucleotide base pair of DNA and RNA, it is recognized as valuable compound in the treatment of cancer.

Main text

Many novel pyrimidine derivatives have been designed and developed for their anticancer activity in the last few years. The present review aims to focus on the structure activity relationship (SAR) of pyrimidine derivatives as anticancer agent from the last decade.

Conclusion

This review intends to assist in the development of more potent and efficacious anticancer drugs with pyrimidine scaffold.

Graphical abstract

Design, Synthesis and Biological Evaluation of Novel 4-(4-Methoxynaphthalen-1-yl)-5-arylpyrimidin-2-amines as Tubulin Polymerization Inhibitors

A novel series of 4-(4-methoxynaphthalen-1-yl)-5-arylpyrimidin-2-amines were designed, synthesized, and evaluated for their anticancer activities. Most of the synthesized compounds exhibited moderate to high antiproliferative activity in comparison to the standard drug cisplatin. Among them, 5i bearing ethoxy at the 4-position of the phenyl was found to be the most active on MCF-7 and HepG2 cancer cell lines, with IC₅₀ values of 3.77 ± 0.36 and 3.83 ± 0.26 µM, respectively. Further mechanism study shown that 5i potently inhibited tubulin polymerization, induced cell cycle arrest at G2/M phase and cell apoptosis in MCF-7 cell line. Furthermore, molecular modeling study suggested that 5i probably binds to the colchicine site of tubulin.

Design, synthesis and antiproliferative evaluation of new tricyclic fused thiazolopyrimidines targeting topoisomerase II: Molecular docking and apoptosis inducing activity

A novel series of thiazolopyrimidines and fused thiazolopyrimidines was designed and synthesized as topoisomerase II alpha inhibitors. All synthesized compounds were screened by the National Cancer Institute (NCI), Bethesda, USA for anticancer activity against 60 human cancer cell lines representing the following cancer types: leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast cancers. Compound 3a was found to be the most potent inhibitor on renal cell line (A-498) causing 83.03% inhibition (IC₅₀ = 1.89 μM). DNA-flow cytometric analysis showed that compound 3a induce cell cycle arrest at G2/M phase leading to cell proliferation inhibition and apoptosis. Moreover, fused thiazolopyrimidines 3a showed potent topoisomerase II inhibitory activity (IC₅₀ = 3.19 μM) when compared with reference compound doxorubicin (IC₅₀ = 2.67 μM). Docking study of all the synthesized compounds showed that compound 3a interacts in a similar pattern to etoposide and stabilizing the topoisomerase cleavage complex (Top2-cc) that accounts for its high potency.

Synthesis of new thienylpicolinamidine derivatives and possible mechanisms of antiproliferative activity

Three thienylpicolinamidine derivatives 4a-c were prepared from their corresponding picolinonitriles 3a-c on treatment with lithium trimethylsilylamide, LiN(TMS)2, followed by a de-protection step using ethanol/HCl (gas). DFT calculations were used to optimize the geometric structure of the newly synthesized picolinamidines. The comparison of DFT calculated spectral data with the experimental data (1H-NMR and 13C-NMR) showed a good agreement. The in vitro antiproliferative activity of the cationic compounds 4a-c was determined against 60 cancer cell lines representing nine types of cancer. The tested picolinamidines were highly active with compounds 4a and 4b eliciting mainly cytotoxic activity with GI values ranging from -7.17 to -86.03. Leukemia (SR and K-562), colon (SW-620 and HT29), and non-small cell lung cancer (NCI-H460) cell lines were the most responsive to the investigated picolinamidines. In particular, 4-methoxyphenyl derivative 4a showed a profound growth deterring power with GI50 of 0.34 μM against SR, 0.43 μM against SW-620, and 0.52 μM against NCI-H460. The three tested picolinamidines elicited potent GI50 values against all tested cell lines at low micromolar to sub-micromolar level. The new picolinamidines were selective and did not affect normal human fibroblasts. The selectivity index ranged from 13-21 μM. The novel picolinamidines downregulated the expression of key genes in the cell cycle, cdk1 and topoII, but did not affect p53 or txnrd1. Compounds 4b and 4c caused a significant reduction in the concentrations of TopoII and MAPK proteins but were devoid of any effect on the activity of caspase 3. Taken together, these promising anticancer candidates are effective at very low concentrations and safe to normal cells, and most probably work through arresting the cell cycle, and therefore, they deserve further investigations.

Novel urea linked ciprofloxacin-chalcone hybrids having antiproliferative topoisomerases I/II inhibitory activities and caspases-mediated apoptosis

A novel series of urea-linked ciprofloxacin (CP)-chalcone hybrids 3a-j were synthesized and screened by NCI-60 cancer cell lines as potential cytotoxic agents. Interestingly, compounds 3c and 3j showed remarkable antiproliferative activities against both colon HCT-116 and leukemia SR cancer cells compared to camptothecin, topotecan and staurosporine with IC₅₀ = 2.53, 2.01, 17.36, 12.23 and 3.1 μM for HCT-116 cells, respectively and IC₅₀ = 0.73, 0.64, 3.32, 13.72 and 1.17 μM for leukemia SR cells, respectively. Also, compounds 3c and 3j exhibited inhibitory activities against Topoisomerase (Topo) I with % inhibition = 51.19% and 56.72%, respectively, compared to camptothecin (% inhibition = 60.05%) and Topo IIβ with % inhibition = 60.81% and 60.06%, respectively, compared to topotecan (% inhibition = 71.09%). Furthermore, compound 3j arrested the cell cycle of leukemia SR cells at G2/M phase. It induced apoptosis both intrinsically and extrinsically via activation of proteolytic caspases cascade (caspases-3, -8, and -9), release of cytochrome C from mitochondria, upregulation of proapoptotic Bax and down-regulation of Bcl-2 protein level. Thus, the new ciprofloxacin derivative 3j could be considered as a potential lead for further optimization of antitumor agent against leukemia and colorectal carcinoma.

Design and synthesis of novel isatin-based derivatives targeting cell cycle checkpoint pathways as potential anticancer agents

In recent years, cell cycle and checkpoint pathways regulation are offering new therapeutic approaches against cancer. Isatin, is a well exploited scaffold in the anticancer domain. Accordingly, the current work describes the design and synthesis of two series of (Z)-3-substituted-2-(((E/Z)-5-substituted-2-oxo-1-substituted-indolin-3-ylidene)hydrazinylidene)-thiazolidin-4-ones, 4(a-s) and (E/Z)-1-substituted-3-(((Z)-3-substituted-4-methylthiazol-2(3H)-ylidene)hydrazineylidene)-5-substituted-indolin-2-ones, 5(a-s). The structures of the synthesized molecules were confirmed by spectral and elemental methods of analyses. Pure diastereomers were further identified with ¹H-¹H-NOESY and confirmed with X-ray crystallography. The target compounds were tested in vitro for their cytotoxicity against three human epithelial cell lines, liver (HepG2), breast (MCF-7), and colon (HT-29) in addition to the diploid human normal cells (WI-38) compared to doxorubicin as a reference drug. Variable cytotoxic effects (IC₅₀ 3.29-100 µmol) were reported on the three cancer cell lines with pronounced selectivity compared to the normal one WI-38. The potency of the most active compounds, 4o, 4s, 5e, 5f, 5l, 5m and 5o (IC₅₀ 3.29-9.92 µmol), in both series associated with the (Z) configurations of N = thiazolidin/ene or one, however, the configuration of the N = isatin moiety seemed to be of no importance to the activity. The tested compounds were grouped for their possible mechanism of action into 4 categories. Compound 4o with no apparent effect on all genes examined. Compounds 4s and 5o affected all genes investigated and seem to have multiple cellular targets; induced the expression of p53 and caspases, and downregulated that of CDK1. Compounds 5l and 5m directly elevated the expression of initiator and effector caspases without going through p53 pathway. Finally, compounds 5e and 5f elevated the expression of p53 and inhibited CDK1. Compounds 4s, 5e, 5f, 5l, 5m, and 5o caused a significant elevation in the activity of cleaved caspase 3 as well. Docking studies on CDK1 revealed that the active molecules bind to the tested enzyme by the same manner of the co-crystallized ligands and the isatin-thiazoldinone/ene scaffold is essential for binding of these molecules.

Pyrazoline Hybrids as Promising Anticancer Agents: An Up-to-Date Overview

Pyrazolines are five-membered heterocycles possessing two adjacent nitrogens. They have attracted significant attention from organic and medicinal chemists due to their potent biological activities and the numerous possibilities for structural diversification. In the last decade, they have been intensively studied as targets for potential anticancer therapeutics, producing a steady yearly rise in the number of published research articles. Many pyrazoline derivatives have shown remarkable cytotoxic activities in the form of heterocyclic or non-heterocyclic based hybrids, such as with coumarins, triazoles, and steroids. The enormous amount of related literature in the last 5 years prompted us to collect all these published data from screening against cancer cell lines, or protein targets like EGFR and structure activity relationship studies. Therefore, in the present review, a comprehensive account of the compounds containing the pyrazoline nucleus will be provided. The chemical groups and the structural modifications responsible for the activity will be highlighted. Moreover, emphasis will be given on recent examples from the literature and on the work of research groups that have played a key role in the development of this field.

Predictions of Drug-Protein Interactions and Study of Magnetically Assisted Release Dynamics of 5-Fluorouracil from Soya Protein-Coated Iron Oxide Core-Shell Nanoparticles

In silico studies were performed using 5-fluorouracil (5-FU) to explore the efficacy of template docking and facilitate designing of drug nanocarrier systems. The binding of human uridine phosphorylase (huPP1) with 5-FU was found to show the following interactions: (1) hydrogen bonds were alleviated by a network of GLN217 and ARG219, (2) hydrophobic interactions were shown by PHE213, THR141, LEU272, and ILE281 (3) positive electrostatic interactions were shown by PHE213, THR141, LEU272, SER142, GLU248, and GLY143. As an experimental supplementation and validation to the adopted computational approach, 5- FU-loaded soya protein-coated iron oxide (SPCIO) core-shell nanoparticles were prepared following microemulsion and co-precipitation techniques and subsequently characterized by FTIR, particle size and zeta potential studies, TEM, XRD, and DSC techniques. Whereas the FTIR spectra confirm the presence of the soya protein and drug 5-FU in the nanoparticles, the zeta potential was found to be suppressed due to the loading of 5-FU. The XRD study confirmed the crystalline nature of the drug-loaded nanoparticles. TEM analysis suggested that the nanoparticles have sizes up to 200 nm and the morphology and size remain almost the same even after loading of the drug 5-FU onto nanoparticles. The soya protein-coated iron oxide nanoparticles demonstrated zero cytotoxicity against fibroblast cells. The controlled release of 5-FU was studied in vitro, and the effects of pH, chemical composition of nanoparticles, extent of drug loading, and simulated biofluids on the controlled release of 5-FU were studied. The swelling of nanoparticles and release of 5-FU were found to increase with increasing strength of the externally applied magnetic field.