ZnO Nanoparticles Catalyst in the Synthesis of Bioactive Fused Pyrimidines as Anti-breast Cancer Agents Targeting VEGFR-2

Design, Synthesis and Anticancer Evaluation of New 1-allyl-4-oxo-6-(3,4,5- trimethoxyphenyl)-1,4-dihydropyrimidine-5-carbonitrile Bearing Pyrazole Moieties

AIM

pyrimidine and pyrazole have various biological and pharmaceutical applications such as antibacterial, antifungal, antileishmanial, anti-inflammatory, antitumor, and anti-cancer.

INTRODUCTION

In this search, the goal is to prepare pyrimidine-pyrazoles and study their anticancer activity.

METHODS

1-allyl-4-oxo-6-(3,4,5-trimethoxyphenyl)-1,4-dihydropyrimidine-5-carbonitrile bearing pyrazoles (4,6-8) have been synthesized. Firstly, the reaction of 1-allyl-2-(methylthio)-4-oxo-6- (3,4,5-trimethoxyphenyl)-1,4-dihydropyrimidine-5-carbonitrile (1) with chalcones 2a-b produced the intermediates 3a-b. The latter was reacted with hydrazine hydrate to give the targets 4a-b. On the other hand, hydrazinolysis of compound 1 yielded the hydrazino derivative 5 which upon reaction with chalcones 2c-i or 1,3-bicarbonyl compounds afforded the compounds 6-8. Finally, the new compounds were characterized by spectral data (IR, 1H NMR, 13C NMR) and elemental analysis. Moreover, they were evaluated for Panc-1, MCF-7, HT-29, A-549, and HPDE cell lines as anticancer activity.

RESULTS

All the tested compounds 3,4,6-8 showed IC50 values > 50 μg/mL against the HPDE cell line. Compounds 6a and 6e exhibited potent anticancer activity where the IC50 values in the range of 1.7- 1.9, 1.4-182, 1.75-1.8, and 1.5-1.9 μg/mL against Panc-1, MCF-7, HT-29, and A-549 cell lines.

CONCLUSION

New pyrimidine-pyrazole derivatives were simply synthesized, in addition, some of them showed potential anticancer activity.

Cancer targeted drug delivery using active low-density lipoprotein nanoparticles encapsulated pyrimidines heterocyclic anticancer agents as microtubule inhibitors

Recently, nanomedicine had the potential to increase the delivery of active compounds to specific cell sites. Nano-LDL particles are recognized as an excellent active nano-platform for cancer-targeted delivery. Loading of therapeutic agents into nano-LDL particles achieved by surface loading, core loading, and apolipoprotein-B100 interaction. Therefore, loading nano-LDL particles’ core with pyrimidine heterocyclic anticancer agents will increase cancer cytotoxic activity targeting tubulin protein. First, by mimicking the native LDL particle's metabolic pathway, and second the agent’s chemical functional groups like the native amino acids cytosine and thymine structures will not be recognized as a foreign entity from the cell’s immune system. Nano-LDL particles will internalize through LDL-receptors endocytosis and transport the anticancer agent into the middle of the cancer cell, reducing its side effects on other healthy cells. Generally, the data revealed that pyrimidine heterocyclic anticancer agents’ size is at the nano level. Agents’ morphological examination showed nanofibers, thin sheets, clusters, and rod-like structures. LDL particles’ size became bigger after loading with pyrimidine heterocyclic anticancer agents and ranged between 121.6 and 1045 nm. Then, particles were tested for their cytotoxicity against breast (MDA468) and prostate (DU145) cancer cell lines as surrogate models with dose-response study 10, 5, 1 µM. The IC₅₀ values of the agents against DU145 and MDA468 possessed cell growth inhibition even at the 1 µM concentration ranges of 3.88 ± 1.05 µM and 3.39 ± 0.97 µM, respectively. In sum, nano-LDL particles proved their efficiency as active drug delivery vehicles to target tubulin in cancer cells.

Recent Advances in Multicomponent Reactions Catalysed under Operationally Heterogeneous Conditions

Multicomponent reactions (MCRs) have been gaining significance and attention over the past decade because of their ability to furnish complex products by using readily available and simple starting materials while simultaneously eliminating the need to separate and purify any intermediates. More so, most of these products have been found to exhibit diverse biological activities. Another paradigm shift which has occurred contemporarily is the switch to heterogeneous catalysis, which results in additional benefits such as the reduction of waste and an increase in the safety of the process. More importantly, it allows the user to recover and reuse the catalyst for multiple runs. In summary, both methodologies adhere to the principles of green chemistry, a philosophy which needs to become overarchingly enshrined. The plethora of reactions and catalysts which have been developed gives hope that chemists are slowly changing their ideology. As a result, this review attempts to discuss multicomponent reactions catalysed by operationally heterogeneous catalysts in the past 10 years. In this review, a further distinction is made between the MCRs which lead to the formation of heterocycles and those which do not.

Al-Hussain S, E. A. Zaki M, H. Asghar B, A. Muhammad Z. Synthesis of spiropyrazoles under organic and nonorganic catalysis

Abstract:

Spiropyrazoles display many biological biological activities such as antitumor, vasodilation, analgesic, phosphodiesterase inhibitors, aldosterone antagonistic, anabolic, androgenic, anti-inflammatory, progestational and salt-retaining activities and they also exert neuroprotection in dopaminergic cell death. Many efforts have been made to obtain these derivatives with high yield and excellent regio-, diastereo- and enantioselectivities. Most of the spiroprazole synthesis methods were proceeded in good to excellent yield in the presence of organic catalysts as for examples squaramide, NHC pre-catalyst, pyrrole derivatives, bis-oxazoline, DMAP, DABCO, thiourea derivatives, DBU, acetic acid and quinoline catalysts. In addition, the inorganic and organo-metallic catalysts have been proven their efficiency in synthesis of various types of spiro-pyrazoles in excellent yield. Thus, in this review we have compiled all citations for the synthesis of spiropyrazoles in the presence of various types of catalysts such as organic, inorganic, and metalorganic catalysts in the range 2020 to 2012. This review article is a useful compilation for researchers interested in the synthesis of spiropyrazole derivatives and will assist them in selecting appropriate catalysts for preparation of their spiropyrazoles.

Dry Grinding Synthesis and Docking Study of Cyclopentanone-Sulfur Containing Compounds with Anti-Proliferative Activity for HepG-2 and A-549 Cancer Cell Lines

BACKGROUND

The dry grinding method is a green technique for efficient organic synthesis with numerous advantages, such as: mild reaction conditions, environmental acceptability, simple segregation and refinement as well as the elevated selectivity and efficiency.

OBJECTIVE

The aim of the present work is to design and synthesize of cyclopentylidene-hydrazino)-thiazole derivatives using dry grinding condition to investigate their antitumor activity aganist two cell lines namely, HepG-2 and A-549.

METHODS

In this context, we synthesized series of thiazole incorporated cyclopentane through hydrazone-group and 2-cyclopentylidenehydrazine-1-carbimidic-2-ethoxy-N-aryl-2-oxoacetohydrazonic thioanhydride under dry grinding within minutes and excellent to good yield.

RESULTS

All spectral data confirmed the proposed structures. The molecular docking studies have been performed using Macrophage Migration Inhibitory Factor (Pdb: 4k9g) and Lysozyme C (Pdb: 2f4a), the overexpressed proteins in human liver cancer cell (HepG-2) and lung cancer cell lines (A-549), respectively, in addition to the antitumor activity investigations contra the two types of tumor cells.

CONCLUSION

Two derivatives 9b and 9d showed the highest antitumor activity against the two cell lines HepG-2 and A-549. Also, docking results revealed high energy score ranging from -7.1590 to -5.9364 Kcal/mol with Macrophage Migration Inhibitory Factor (Pdb: 4k9g) which is more than the energy score = -4.118 Kcal/mol of co-crystallized ligand. Moreover, the tested derivatives showed energy score varies from -6.0802 to -4.5503 Kcal/mol against Lysozyme C (Pdb: 2f4a).

Novel thiazole derivatives incorporating phenyl sulphonyl moiety as potent BRAFV600E kinase inhibitors targeting melanoma

Novel thiazole derivatives possessing phenyl sulfonyl moiety were designed and synthesized as B-RAFV600E kinase inhibitors based on the clinically-approved anticancer drug, dabrafenib. All target compounds showed significant inhibition of B-RAFV600E kinase enzyme at nanomolar levels. Compounds 7b and 13a revealed excellent B-RAFV600E inhibitory activity, superior to that of dabrafenib with IC₅₀ values of 36.3 ± 1.9, 23.1 ± 1.2, and 47.2 ± 2.5 nM, respectively. Moreover, the title compounds were much more selective toward B-RAFV600E kinase than B-RAF wild type. In addition, the most potent compounds were further evaluated for their anticancer activity against B-RAFV600E-mutated and wild type melanoma cells. A positive correlation between the cytotoxic activity and selectivity for B-RAF V600E over B-RAF wild type was clearly observed for compounds 7b, 11c, 13a, and 17. All the screened compounds potently inhibited the growth of WM266.4 melanoma cells with IC₅₀ values in the range from 1.24 to 17.1 μM relative to dabrafenib (IC₅₀ = 16.5 ± 0.91 μM). Compounds 7b, 11a and 11c, 13a, and 17 were much more potent than dabrafenib against B-RAFV600E-mutated WM266.4 melanoma cells. Furthermore, compound 7b suppressed the phosphorylation of downstream ERK1/2 from WM266.4 cells. Also, the docking study revealed the proper orientation and well-fitting of the title compounds into the ATP binding site of B-RAFV600E kinase.

Thiazole derivatives 7b and 13a were superior to dabrafenib against B-RAFV600E kinase and potently inhibited the growth of WM266.4 melanoma cells. Compound 7b suppressed the phosphorylation of downstream ERK1/2 from WM266.4 cells.

Pyrazoles and fused pyrimidines: Synthesis, structure elucidation, antitubercular activity and molecular docking study

BACKGROUND

Synthesis of new heterocyclic drugs in short reaction time with sufficient quantity is considered as a target for several pharmaceutical scientists. Thus, organic reactions proceeded on the surface of nano-sized catalysts to speed up the stimulation process.

OBJECTIVE

we aimed in this research to synthesize a new series of heterocyclic compounds carrying pyrazole moiety in the presence of ZnO nano-catalyst to investigate their anti-tubercular activity.

METHODS

ZnO(NPs) was used in synthesis of novel series of thienylpyrazolopyrimidines bearing arylazo group by reaction of thiophene-enaminone and the amino-arylazopyrazoles in excellent yield. On the other hand, another series of theinyl-pyrazoles was synthesized through the reaction of the same enaminone with hydrazonoyl chlorides but the usage of ZnO(NPs) failed in such reactions.

RESULTS

The proposed structures of the products and the mechanistic pathways of the reactions were assured based on the spectral data and chemical evidences. Thienylpyrazole derivatives were assessed for their activity as Mycobacterium tuberculosis inhibitor and their results revealed that two thienylpyrazole derivatives 24d & 24f showed the most significant anti-mycobacterial activity with MIC values 0.70 & 1.29 µM/mL, respectively comparing with the MIC value = 0.60 µM/mL of the standard drug Rifampicin. Furthermore, the most active thienylpyrazole derivatives were investigated for their cytotoxic impact versus normal cells WI-38 (Normal human Lung fibroblast cells) using MTT assay. These thienylpyrazole derivatives exhibited good selective index profile. Moreover, 1,3,4-trisubstituted pyrazole analogues showed good interaction with the active site of enoyl-acyl carrier protein reductase (Mt InhA) through the molecular docking studies.

CONCLUSION

We succeeded to synthesis a new series of heterocyclic compounds carrying pyrazole moiety in the presence of ZnO nano-catalyst as anti-tubercular agents.

Synthesis of Thiazolyl-N-phenylmorpholine Derivatives and their Biological Activities

BACKGROUND

Morpholine and thiazole rings are two heterocycles which are wellknown with a wide spectrum of different biological activities, especially antitumor activity.

OBJECTIVE

The aim of the work is to design and synthesize hybrid heterocyclic compounds of morpholine and thiazole moieties via the reaction of morpholino-thiosemicarbazone derivatives with various α-halocarbonyl compounds and screening their antitumor activity against three tumor cell lines namely, TK-10, MCF-7 and UACC-62.

METHODS

An efficient synthesis of a series of N-phenylmorpholine derivatives linked with thiazole moiety was accomplished. The reaction of N-subistituted-2-(N-phenylmorpholine)ethylidene) hydrazine- 1-carbothioamide (thiosemicarbazone derivative) with acetyl and ester-hydrazonoyl chlorides, α-chloroketones, or α-bromoesters afforded the corresponding thiazole derivatives pendent to N-phenylmorpholine moiety in good to excellent yields.

RESULTS

Mass, 1H NMR, 13C NMR, and elemental analysis were used to confirm the structure of all the new derivatives. The antitumor activities of synthesized N-phenylmorpholine-thiazole derivatives were investigated against three tumor cells namely, TK-10, MCF-7 and UACC-62. The results of such investigation indicated that some derivatives showed good potential to inhibit the growth of the two cells of the tested tumor cells. One of the tested compounds, N-ethyl thiosemicarbazone derivative 7 revealed potent growth inhibition of all the three tumor cells.

CONCLUSION

We have succeeded to synthesize a series of N-phenylmorpholine derivatives pendant to thiazole moiety as antitumor agents.

Nano-sized formazan analogues: Synthesis, structure elucidation, antimicrobial activity and docking study for COVID-19

Three series of nanosized-formazan analogues were synthesized from the reaction of dithiazone with various types of α-haloketones (ester and acetyl substituted hydrazonoyl chlorides and phenacyl bromides) in sodium ethoxide solution. The structure and the crystal size of the new synthesized derivatives were assured based on the spectral analyses, XRD and SEM data. The antibacterial and antifungal activities were evaluated by agar diffusion technique. The results showed mild to moderate antibacterial activities and moderate to potent antifungal activities. Significant antifungal activities were observed for four derivatives 3a, 3d, 5a and 5g on the pathogenic fungal strains; Aspergillus flavus and Candida albicans with inhibition zone ranging from 16 to 20 mm. Molecular docking simulations of the synthesized compounds into leucyl-tRNA synthetase editing domain of Candida albicans suggested that most formazan analogues can fit deeply forming stable complexes in the active site. Furthermore, we utilized the docking approach to examine the potential of these compounds to inhibit SARS-CoV-2 3CLpro. The results were very promising verifying these formazan analogues as a hopeful antiviral agents.

Novel 2-indolinone thiazole hybrids as sunitinib analogues: Design, synthesis, and potent VEGFR-2 inhibition with potential anti-renal cancer activity

Novel 2-indolinone thiazole hybrids were designed and synthesized as VEGFR-2 inhibitors based on sunitinib, an FDA-approved anticancer drug. The proposed structures of the prepared 2-indolinone thiazole hybrids were confirmed based on their spectral data and CHN analyses. The target compounds were screened in vitro for their anti-VEGFR-2 activity. All tested compounds exhibited a potent submicromolar inhibition of VEGFR-2 kinase with IC₅₀ values ranging from 0.067 to 0.422 μM, relative to sunitinib reference drug (IC₅₀ = 0.075 ± 0.002 μM). Compounds 5, 15a, 15b, 17, 19c displayed excellent VEGFR-2 inhibitory activity, comparable or nearly equipotent to sunitinib. Compound 13b stood out as the most potent against VEGFR-2 showing IC₅₀ value of 0.067 ± 0.002 μM, lower than that of sunitinib. In addition, the most potent derivatives were assessed for their anticancer activity against two renal cancer cell lines. Compound 13b (IC₅₀ = 3.9 ± 0.13 μM) was more potent than sunitinib (IC₅₀ = 4.93 ± 0.16 μM) against CAKI-1 cell line. Moreover, thiazole 15b displayed excellent anticancer activity against CAKI-1 cell line (IC₅₀ = 3.31 ± 0.11 μM), superior to that of sunitinib (IC₅₀ = 4.93 ± 0.16 μM). Thiazole 15b was also equipotent to sunitinib (IC₅₀ = 1.23 ± 0.04 μM) against A498 cell line. Besides, compound 15b revealed a safety profile much better than that of sunitinib against normal human renal cells. Furthermore, a docking study revealed a proper fitting of the most active compounds into the ATP binding site of VEGFR-2, rationalizing their potent anti-VEGFR-2 activity.

Synthesis and DNA binding of novel bioactive thiazole derivatives pendent to N-phenylmorpholine moiety

An easy access to a series of N-phenylmorpholine derivatives linked with thiazole or formazan moieties were achieved using simple experimental procedure under conventional and microwaves irradiation conditions. The reaction of 2-(N-phenylmorpholine)ethylidene)hydrazine-1-carbothioamide derivatives and [1-(4-morpholin-4-yl-phenyl)-ethylidene]-hydrazine with a variety of hydrazonoyl chlorides or phenacyl bromide derivatives afforded the corresponding thiazoles or N-substitutedhydrazino-derivatives linked to N-phenylmorpholine moiety in good to excellent yields. The structures of the newly synthesized compounds were fully emphasized and characterized by spectroscopic as well as elemental analyses. The mode of binding of some selected compounds with SS-DNA was evaluated using UV-Vis absorption, and viscosity measurements. The results showed intercalation binding mode of most of the tested compounds. Both antimicrobial and anti-cancer activities have been studied for some selected compounds from synthetic derivatives. Their results showed a remarkable efficacy for some derivatives against both examined microbes and cancer cells.

Ethanol-Drop Grinding Approach: Cadmium Oxide Nanoparticles Catalyzed the Synthesis of [1,3]Dioxolo[g][1]benzopyran-6-carboxylic Acids and Pyrido[d]pyrimidine-7-carboxylic Acids

AIM AND OBJECTIVE

In the last decades, it has extensively been verified that nanostructured transition metal oxides emerge as inexpensive, available and extremely efficient heterogeneous catalysts in chemical transformations. The high electrical conductivity, high carrier concentration, and improved reactivity in cadmium oxide nanoparticles (CdO NPs) make it as a potential candidate for applications in the fields of nanocatalysis. [1]Benzopyran and pyridopyrimidine derivatives compose major classes of heterocyclic compounds, which have a wide spectrum of biological activities.

MATERIALS AND METHODS

In the present work, we report a facile and highly effective synthesis of 8- aryl-8H-[1,3]dioxolo[4,5-g][1]benzopyran-6-carboxylic acids and 1,3-dimethyl-2,4-dioxo-5- phenyl-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids via CdO NPs catalyzed cyclo condensation reaction of 4-substituted phenylmethylidenepyruvic acids with 3,4- methylenedioxyphenol or 6-amino-1,3-dimethyluracil, which was accomplished under ethanoldrop grinding at room temperature. The described catalyst was prepared successfully by a simple precipitation method and characterized by the Fourier transformed infrared absorption (FT-IR) spectroscopy, X-Ray diffraction (XRD) analytical technique, and scanning electron microscopy (SEM).

RESULTS

A number of [1,3]dioxolo[g][1]benzopyran-6-carboxylic acids and pyrido[d]pyrimidine- 7-carboxylic acids were effectively synthesized in high yields (96-98%) within short reaction times (10-15 min). All synthesized compounds were well-characterized by IR, 1H and 13C NMR spectroscopy, and also by elemental analyses.

CONCLUSION

In summary, we have developed a very simple and impressive procedure for the synthesis of 8-aryl-8H-[1,3]dioxolo[4,5-g][1]benzopyran-6-carboxylic acids and 1,3-dimethyl- 2,4-dioxo-5-phenyl-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids as biologically interesting structures in the presence of CdO NPs as an efficient recyclable heterogeneous catalyst. The remarkable advantages for the offered protocol compared with traditional methods are short reaction time, good yields of the products, and the ease of operation with simple work-up procedure.

Synthesis and molecular docking study of new pyrazole derivatives as potent anti-breast cancer agents targeting VEGFR-2 kinase

Based on the previous studies that revealed the valuable role of pyrazole scaffold in cancer management and VEGFR-2 inhibition, a new set of pyrazole conjugated with pyrazoline, triazolopyrimidine and pyrazolone moieties were synthesized and investigated for their anticancer efficiency against human breast cancer MCF-7. The anticancer screening revealed the significant sensitivity of breast carcinoma towards compounds 4b, 5c, 6c, 7b, 7c and 12c with IC₅₀ values ranging from 16.50 - 26.73 µM in comparison with tamoxifen (IC₅₀ = 23.31 µM). Moreover, the new analogues were further examined for their VEGFR-2 inhibitory activity, among the tested derivatives 5c, 6c, 7b, 7c and 12c displayed prominent inhibitory efficiency versus VEGFR-2 kinase with % inhibition ranging from 70 to 79%. Compounds 6c, 7c and 12c revealed inhibitory efficiency in nanomolar level with IC₅₀ (913.51, 225.17 and 828.23 nM, respectively) comparing to sorafenib (IC₅₀ = 186.54 nM). Flow cytometric analysis revealed that the promising compound 12c prompted pre-G1 apoptosis and cell growth cessation at G2/M phase and stimulated apoptosis via activation of caspase-3. Moreover, molecular docking study of the promising derivatives was performed to highlight their binding modes and interactions with the amino acid residues of VEGFR-2 enzyme.

Heterocycle Compounds with Antimicrobial Activity

Background:

Bacterial infections are a growing problem worldwide causing morbidity and mortality mainly in developing countries. Moreover, the increased number of microorganisms, developing multiple resistances to known drugs, due to abuse of antibiotics, is another serious problem. This problem becomes more serious for immunocompromised patients and those who are often disposed to opportunistic fungal infections.

Objective:

The objective of this manuscript is to give an overview of new findings in the field of antimicrobial agents among five-membered heterocyclic compounds. These heterocyclic compounds especially five-membered attracted the interest of the scientific community not only for their occurrence in nature but also due to their wide range of biological activities.

Method:

To reach our goal, a literature survey that covers the last decade was performed.

Results:

As a result, recent data on the biological activity of thiazole, thiazolidinone, benzothiazole and thiadiazole derivatives are mentioned.

Conclusion:

It should be mentioned that despite the progress in the development of new antimicrobial agents, there is still room for new findings. Thus, research still continues.

Discovery of thiazole-based-chalcones and 4-hetarylthiazoles as potent anticancer agents: Synthesis, docking study and anticancer activity

The crucial need for novel antitumor agents with high selectivity toward cancer cells has promoted us to synthesize new series of thiazole-based chalcones and 4-hetarylthiazoles (rigid chalcones). The synthesis of thiazolyl chalcones and 4-hetarylthiazoles and the assertion of their structure are described. Their anti-proliferative activity was estimated against three human cancer cell lines; HepG-2, A549 and MCF-7. 3-(4-Methoxyphenyl)-1-(5-methyl-2-(methylamino)thiazol-4-yl)prop-2-en-1-one (chalcone derivative 3a) showed significant and broad antitumor activity that was more potent than Doxorubicin. In addition, compounds 3d, 3e and 7a displayed potent activity compared to Doxorubicin. Additionally, these compounds were less toxic on normal lung cells WI-38 with high selectivity index. Further study on 3a regarding its effect on the normal cell cycle profile in A549 cells demonstrated cell cycle arrest at the G2/M phase together with rise in the percentage of the apoptotic pre-G1 cells. CDK1/CDK2/CDK4 inhibition assays were carried out on 3a, 3d, 3e and 7a and the results revealed non selective inhibition on the tested CDKs with IC₅₀ values of 0.78-1.97 µM. Moreover, docking study predicted that 3a, 3d, 3e and 7a can fit in the ATP binding site of CDK1 enzyme. The apoptosis induction potential of 3a, 3d, 3e and 7a was also estimated against some apoptosis markers. Interestingly, they elevated the level of Bax by 6.36-10.12 folds and reduced the expression of Bcl-2 by 1.94-4.12 folds compared to the control. Furthermore, they increased both active caspase-3 and p53 levels by 8.76-10.56 and 6.85-10.36 folds, respectively higher than the control which indicates their potential to induce apoptosis.

Synthesis and Antimicrobial Evaluation of Novel Pyrazolopyrimidines Incorporated with Mono- and Diphenylsulfonyl Groups

A novel series of pyrazolo[1,5-a]pyrimidine ring systems containing phenylsulfonyl moiety have been synthesized via the reaction of 2-(phenylsulfonyl)-1-(4-(phenylsulfonyl) phenyl)ethan-1-one, 2-benzenesulfonyl-1-(4-benzenesulfonyl-phenyl)-3-dimethylamino-propenone and 3-(dimethylamino)-1-(4-(phenylsulfonyl)phenyl)prop-2-en-1-one each with various substituted aminoazopyrazole derivatives in one pot reaction strategy. The proposed structure as well as the mechanism of their reactions were discussed and proved with all possible spectral data. The results of antimicrobial activities of the new sulfone derivatives revealed that several derivatives showed activity exceeding the activity of reference drug. Contrary to expectations, we found that derivatives containing one sulfone group are more effective against all bacteria and fungi used than those contain two sulfone groups.

New Series of Thiazole Derivatives: Synthesis, Structural Elucidation, Antimicrobial Activity, Molecular Modeling and MOE Docking

Based on the extensive biological activities of thiazole derivatives against different types of diseases, we are interested in the effective part of many natural compounds, so we synthesized a new series of compounds containing di-, tri- and tetrathiazole moieties. The formation of such derivatives proceeded via reaction of 2-bromo-1-(4-methyl-2-(methylamino)thiazol-5-yl)ethan-1-one with heterocyclic amines, o-aminothiophenol and thiosemicarbazone derivatives. The structure and mechanistic pathways for all products were discussed and proved based on spectral results, in addition to conformational studies. Our aim after the synthesis is to investigate their antimicrobial activity against various types of bacteria and fungi species. Preceeding such an investigation, a molecular docking study was carried out with selected conformers, as representative examples, against three pathogen-proteins. This preliminary stage could support the biological application. The potency of these compounds as antimicrobial agents has been evaluated. The results showed that derivatives which have di- and trithiazole rings displayed high activity that exceeds the used standard antibiotic.