Novel Triazolothiadiazole and Triazolothiadiazine Derivatives Containing Pyridine Moiety: Design, Synthesis, Bactericidal and Fungicidal Activities

Synthesis of pyrido-annelated [1,2,4,5]tetrazines, [1,2,4]triazepine, and [1,2,4,5]tetrazepines for anticancer, DFT, and molecular docking studies

In this strategy, we attempt to design various novel nitrogen-rich heterocycles in one molecule. Green, simple, and efficient aza-annulations of an active, versatile building block, 1-amino-4-methyl-2-oxo-6-phenyl-1,2-dihydropyridine-3-carbonitrile (1), with different bifunctional reagents were developed under solvent-free conditions, resulting in the bridgehead tetrazines and azepines (triazepine and tetrazepines). Pyrido[1,2,4,5]tetrazines have been synthesized through two pathways; [3 + 3]- and [5 + 1]-annulations. In addition, pyrido-azepines have been developed by applying [4 + 3]-and [5 + 2]-annulations. This protocol establishes an efficient technique for synthesizing essential biological derivatives of 1,2,4,5-tetrazines, 1,2,4-triazepines, and 1,2,4,5-tetrazepine, tolerating a diverse variety of functionalities without the need for catalysis and fast reaction rates in high yields. The National Cancer Institute (NCI, Bethesda, USA) examined twelve compounds produced at a single high dosage (10^-5 M). Compounds 4, 8, and 9 were discovered to have potent anticancer action against certain cancer cell types. To explain NCI results, the density of states was calculated to conduct a better description of the FMOs. The molecular electrostatic potential maps were created to explain a molecule's chemical reactivity. In silico ADME experiments were performed to better understand their pharmacokinetic characteristics. Finally, the molecular docking investigations on Janus Kinase-2 (PDB ID: 4P7E) were carried out to study the binding mechanism, binding affinity, and non-bonding contacts.

Isolation of Haematococcus lacustris as source of novel anti-multi-antibiotic resistant microbes agents; fractionation and identification of bioactive compounds

In this work, freshwater microalga, Haematococcus lacustris was isolated from the River Nile, identified and deposited in genebank under name of H. lacustris isolate REH10 with accession number OK336515. N-hexane extract was produced high inhibition effects against multi-antibiotic resistant pathogens. The n-Hexane extract was fractionated and 2 fractions (F3 & F4) exhibited high antibacterial activity (15 - 20 mm) compared with other fractions. Thus, they sub-fractionated and 2 sub-fractions produced from the F3 had high inhibition activity against all tested pathogens (18-20 mm). To identify the main compounds responsible for inhibition growth of multi-drug resistance bacteria, GC-MS chromatogram analyses was applied on the F3 and its sub-fractions 2 and 3. Five compounds detected in the 2 sub-fractions. Palmitic acid was identified as the first report antibacterial agent. The antioxidant activity of SF3-3 was reached to 86 and 80.5% for DPPH and ABTS.⁺ tests, respectively.

Discovery of Quinazoline-2,4(1H,3H)-Dione Derivatives as Potential Antibacterial Agent: Design, Synthesis, and Their Antibacterial Activity

In this paper, we report on the design and synthesis of a novel series of quinazoline-2,4(1H,3H)-dione derivatives as fluoroquinolone-like inhibitors of bacterial gyrase and DNA topoisomerase IV to identify and develop antimicrobial agents to prevent bacterial resistance problems. Their structures were confirmed using spectroscopic analyses (IR, NMR, and EI-MS). The novel quinazoline-2,4(1H,3H)-dione derivatives were evaluated for their antimicrobial activities against Gram-positive and Gram-negative bacterial strains using the Agar well diffusion method to study the antimicrobial activities and compared them with the standard drugs. Most compounds displayed moderate activity. Among the tested compounds, the most promising compounds 13 and 15 provided broad bioactive spectrum against Gram-positive and Gram-negative strains compared to the standard drugs.

Novel allyl-hydrazones including 2,4-dinitrophenyl and 1,2,3-triazole moieties as optical sensor for ammonia and chromium ions in water

It is critical to take safety action if carcinogenic heavy metals and ammonia can be detected quickly, cheaply, and selectively in an environmental sample. As a result, compound 4a [4-(1-(2-(2,4-Dinitrophenyl)hydrazineylidene)-3-(naphthalen-2-yl)allyl)-5-methyl-1-phenyl-1 H-1,2,3-triazole] and compound 4b [4-(1-(2-(2,4-Dinitrophenyl)hydrazineylidene)-3-(naphthalen-2-yl)allyl)-1-(4-fluorophenyl)-5-methyl-1 H-1,2,3-triazole] were prepared. The aldol condensation process of 4-acetyl-1,2,3-triazoles 1a,b (Ar = C₆H₄; 4-FC₆H₄) with 2-naphthaldehyde yields 1-acetyl-1,2,3-triazoles 1a,b (Ar = C₆H₄; 4-FC₆H₄) (5-methyl-1-aryl-1 H-1,2,3-triazol-4-yl) -3-(naphthalen-2-yl)prop-2-en-1-ones 3a,b with a yield of around 95%. The target compounds 4a,b are obtained in around 88% yield by condensation of 3a,b with (2,4-dinitrophenyl)hydrazine in a refluxing acidic medium. Compounds 4a,b exhibited possible colorimetric detection for chromium ion in the range of 0–14 ppm and ammonia in the range of 0–20 ppm. As a result, this research suggests that strong electron-withdraw groups in related probes can improve anion detection ability, while the conjugation effect should also be considered while building structures.

Synthesis of novel seco-acyclo-N-diazolyl-thione nucleosides analogous derived from acetic acid: characterization, complex formation with ions Pb(II), Hg(II) and antibacterial activity

Three diazoles namely 5-methyl-1,3,4-oxadiazole -2(3H)-thione, 5-methyl-1,3,4-thiadiazol-2(3H)-thione and 4-amino-5-methyl-2H-1,2,4-triazole-3-thiol were synthesized from acetic acid or ethyl acetate. Seco-acyclo-N-nucleoside analogous was synthesized by condensation of 1,3-benzylidine-glyceryl-2-tosylate with the three diazoles. Structural proof was based upon IR, ¹H-NMR, ¹³C-NMR spectroscopy and MS measurements. The tendency to form complex between 1,3,4-oxadiazole and 1,3,4-thiadiazoles and Pb(II) and Hg(II) ions was achieved, and their structures were assigned by observing some changes in physical properties such as, MP, coloration, R_f (TLC), IR and UV spectroscopy. Most compounds were tested in vitro against Gram-positive and Gram-negative bacteria and showed variable activity. Hg²⁺ complexes of oxadiazole and thiadiazole derivatives exhibited appreciable antibacterial effect at lower MIC, compatible to the reference vancomycin. Similarly, oxadiazole-nucleoside exhibited high effect on Gram-positive bacteria.

Design, Synthesis, Molecular Modeling and Anti-HIV Assay of Novel Quinazolinone Incorporated Coumarin Derivatives

BACKGROUND

The emergence of drug-resistant viral strains has created the need for the development of novel anti-HIV agents with a diverse structure that targets key enzymes in the HIV lifecycle.

OBJECTIVE

Considering the pharmacophore of integrase inhibitors, one of the validated targets for anti-HIV therapy, we designed a quinazolinone incorporated coumarin scaffold to affect HIV.

METHODS

Coumarin is a beta enol ester and also a well-known drug scaffold. Designed structures were prepared using a one-pot three-component reaction from 3-amino-4-hydroxycoumarin, isatoic anhydride and benzaldehyde derivatives.

RESULTS

In vitro anti-HIV and cytotoxicity assay indicated that more than half of the compounds had EC50 values lower than 50 µM. Unsubstituted phenyl derivative showed the highest activity and selectivity with an EC50 value of 5 µM and a therapeutic index of 7. Compounds were docked into the integrase active site to investigate the probable mechanism of action. Accordingly, the hydroxyl moiety of coumarin along with the carbonyl of the quinazolinone ring could function as the metal chelating group. Quinazolinone and phenyl groups interact with side chains of IN residues, as well.

CONCLUSION

Here, a novel anti-HIV scaffold is represented for further modification and in-vivo studies.

Effective Pharmacophore for CDC25 Phosphatases Enzyme Inhibitors: Newly Synthesized Bromothiazolopyrimidine Derivatives

BACKGROUND

Thiazolopyrimidine analogues are versatile synthetic scaffold possessing wide spectrum of biological interests involving potential anticancer activity.

OBJECTIVE

To report the synthesis of novel bromothiazolopyrimidine derivatives and the study of both molecular modeling and in-vitro anticancer activity.

METHODS

Novel bromothiazolopyrimidine derivatives 5-18 have been prepared from 2-bromo-3-(4- chlorophenyl)-1-(3,4-dimethylphenyl)-propenone 3 as a key starting compound. The anti-cancer activities of the new compounds were evaluated against HepG2, MCF-7, A549 and HCT116 cell lines.

RESULTS

The compounds 16, 17 and 18 showed cytotoxic and growth inhibitory activities on both colon and lung cells. The cytotoxic activities of the novel synthetic compounds 8, 9, 11, 16, 17 and 18 were due to CDC25 phosphatases inhibition as shown by the enzymatic binding assay. Although compounds 8, 9 and 11 have only demonstrated CDC25B phosphatases inhibition.

CONCLUSION

The novel bromothiazolopyrimidine derivatives showed promising in vitro anticancer activities against colon cancer HCT116 and lung cancer A549 cell lines comparable to the anticancer drug doxorubicin.

Synthesis of arylidene hydrazinylpyrido[2,3-d]pyrimidin-4-ones as potent anti-microbial agents

Combination of arylidene hydrazinyl moiety with pyrido[2,3-d]pyrimidin-4-one skeleton in compounds 7‒26 results in the output of unprecedented anti-microbial agents. Arylidene hydrazinyl based on Pyrido[2,3-d]pyrimidin-4-one analoges 7‒26 prepared by the treatment of [2,3-d]pyrimidin-4-ones 6a,b with various aromatic aldehydes. The antimicrobial action for recently synthesized compounds was considered towards gram positive bacterial species (Staphylococcus aurous ATCC- 47077; Bacillus cereus ATCC-12228), gram negative bacterial species (Escherichia coli ATCC-25922; Salmonella typhi ATCC-15566) and Candida albicans ATCC-10231 as fungal strains. The antimicrobial action expanded by expanding the electron donating group in position 2 and 5 for Pyrido[2,3-d]pyrimidin-4-one core. Derivatives 13, 14, 15, 16 and 12; individually appeared hopeful anti-microbial action towards all strains utilized with inhibition zone higher than that of standard reference drug with lowest MIC.

Enzymes immobilization onto magnetic nanoparticles to improve industrial and environmental applications

Enzymes as specific natural biocatalysts are present in all living organisms and they play a key role in the biochemical reactions inside, as outside the cell. Despite the wide range of environmental, medical, agricultural, and food applications, the high cost, non-reusability, and limited stability of soluble (non-immobilized) enzymes are considered barriers to their commercial application. Immobilization techniques are an effective strategy for solving problems associated with free enzymes in terms of improving the efficiency and stability of catalytic enzymes, as well as enhancing their separation and reusability in continuous industrial applications. Out of different supporting materials, magnetic nanoparticles are considered as the future trend for enzyme immobilization due to their exceptional properties regarding stabilization, easy recovery and reuse. Some recent techniques of enzyme immobilization on magnetic nanoparticles will be detailed hereafter in the chapter.

Nematicidal activity of thermostable alkaline protease produced by Saccharomonospora viridis strain Hw G550

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Isolation and identification of thermo alkaliphilic actinomycetes.

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Obtaining of thermostable alkaline protease enzyme.

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Evaluation of the nematicidal activity of obtained protease.

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Application of thermostable alkaline protease as nemticidal agent.

Application of thermostable alkaline protease to control the harmful nematodes was investigated in the current study. A total of 14 proteolytic actinomycetes were isolated from Egyptian harsh environments. Out of them, isolate G550 exhibited the highest proteolytic activity (528.9 U/ml). Protease from isolate G550 exhibited high nematicidal activity against M. incognita under laboratory conditions and caused hydrolysis of J₂S cuticle. This isolate was identified using molecular techniques and deposited in GenBank under name of Saccharomonospora viridis strain Hw G550 with accession number: MF152631. The G550 protease was extracted, characterized and applied under greenhouse conditions as nematicidal agent. This enzyme exhibited maximum activity and stability at alkaline pH (8) and thermal conditions (50–60 °C). Also, the results showed that, all treatments using protease caused a significant decrease in nematode reproduction and increasing in the plant properties. Finally, the thermo alkaliphilic protease could be used as bio-control agent against RKN.

First Synthesis for Bis-Spirothiazolidine Derivatives as a Novel Heterocyclic Framework and Their Biological Activity

BACKGROUND

Spirothiazolidines are versatile synthetic scaffold possessing wide spectrum of biological interests involving potential anticancer activity.

OBJECTIVE

To report the first synthesis of Bis Spiro-thiazolidine as a novel heterocyclic ring system.

METHODS

One-pot three-component reaction including condensation of p-phenyllene diamine; cyclohexanone and thioglycolic acid produced Spiro-thiazolidine 4, which underwent further condensation with cyclohexanone and thioglycolic acid with equimolar ratio to introduce Bis-Spiothiazolidine 5 as the first synthesis. Also, bis spiro-thiazolidine arylidene derivatives 6-13 were synthesized by the reaction of Bis-Spiothiazolidine 5 with different aromatic benzaldehydes.

RESULTS

Four compounds 13, 12, 9 and 11 have shown highly significant anticancer activity compared to Doxorubicin® (positive control) against Human liver carcinoma (HepG2) and Human Normal Retina pigmented epithelium (RPE-1) cell lines.

CONCLUSION

The novel bis-spirothiazolidine deriviatives have been synthesized for the first time and showed excellent anticancer activities compare with the corresponding spirothiazolidine derivatives.

Development of a Novel Series of Anticancer and Antidiabetic: Spirothiazolidines Analogs

4-(4-Aminophenyl)-1-thia-4-azaspiro[4.5]decan-3-one 1 was prepared and allowed to react with nitrogen nucleophiles to give the corresponding hydrazones 2–4. Further, compound 1 underwent diazotization and afforded the parallel hydrazono derivative 5; moreover, compound 1 refluxed with active methylene derivatives yielded the corresponding aminospirothiazolo pyridine–carbonitrile derivative 6 and spirothiazolopyridinone–carbonitrile derivative 7. Condensation of spirothiazolidine 1 with 4-chlorobenzaldehyde gave the corresponding spiro arylidiene derivative 8, which was utilized as a component of Micheal addition to react with excess of nitrogen nucleophiles to yield novel ring frameworks 4-(3′-(4-chlorophenyl)–spiro [cyclohexane-1,5′-pyrazolo[3,4-d]thiazol]-6′(1′H)-yl)aniline (9) and 4-(3′-(4-chlorophenyl)-6′H- spiro[cyclohexane-1,5′-thiazolo[5,4-d]isoxazol]-6′-yl)aniline (10). Finally, when spirothiazolo pyridinone–carbonitrile derivative 7 sodium salt generated in situ was reacted with different alkyl halides, it produced the corresponding N-derivatives 12–16. Three compounds, 6, 14, and 16, showed high significantly anticancer activities compared with Doxorubicin® (positive control) against human breast carcinoma (MCF-7) and human liver carcinoma (HepG-2) cell lines. On the other hand, compounds 6 and 9 showed higher therapeutic indices for both of alpha-amylase inhibitor and alpha-glucosidase inhibitor than the other tested compounds compared with the antidiabetic Acarbose (positive control).

Microbiological evaluation of infant foods quality and molecular detection of Bacillus cereus toxins relating genes

A 205 samples representing eight different infant foods with various based materials were collected and analyzed for their microbiological properties. The contamination rate by aerobic spore formers was achieved 100% in milk based infant food with fruit, vegetables, honey, rice and infant milk powder. While, it was detected in 95, 60 and 65% of the infant food with wheat milk based, ready to use (infant food with fruit) and ready to use (infant food with vegetables), respectively. Biochemical Identification and API 50 CHB used to identify the obtained isolates and revealed that B. subtilis was the most frequently occurring Bacillus spp. Followed by B. licheniformis and B. circulans. While B. cereus was detected in 10.20% of the total isolates. Moreover, B. cereus was confirmed in 21.2% of milk based fruit, vegetables (15.7%), honey (17.2%), rice (14.1%) and wheat (12%) and vanished in the infant milk powder samples. Although, B. cereus noted in lower percentage but this strain is considered as the more harmful one in lower numbers. For that, the following part is focused on B. cereus. Forty five isolates obtained from B. Cereus contaminating samples were screened for prevalence of 3 important virulent enterotoxigenic genes using PCR technique. The CYTK gene had the highest presence which detected in 43 isolates (95.5%), followed by NHEC gene detected in 32 isolates. However, the HBLA gene was detected in just 5 isolates. So, many processes should be applied for controlling of pathogens to preserve infant lives.