Folate antagonists. 4. Antimalarial and antimetabolite effects of 2,4-diamino-6-((benzyl)amino)pyrido(2,3-d)-pyrimidines

Synthesis, in vitro Α-Glucosidase, and acetylcholinesterase inhibitory activities of novel Indol-Fused Pyrano[2,3-D]Pyrimidine compounds

In this study, new indol-fused pyrano[2,3-d]pyrimidines were designed and synthesized. These products were obtained in moderate to good yields and their structures were assigned by NMR, MS, and IR analysis. Afterwards, the biological important of the products was highlighted by evaluating in vitro for α-glucosidase inhibitory activity as well as acetylcholinesterase (AChE) inhibitory activity. Eleven products revealed substantial inhibitory activity against α-glucosidase enzyme, among which, two most potent products 11d,e were approximately 93-fold more potent than acarbose as a standard antidiabetic drug. Besides that, product 11k exhibited good AChE inhibition. The substituents on the 5-phenyl ring, attached to the pyran ring, played a critical role in inhibitory activities. The biological potencies have provided an opportunity to further investigations of indol-fused pyrano[2,3-d]pyrimidines as potential anti-diabetic agents.

Microwave-assisted synthetic method of novel Bi2O3 nanostructure and its application as a high-performance nano-catalyst in preparing benzylidene barbituric acid derivatives

In this study, controllable and optimal microwave irradiation has been used to synthesize the novel nanostructures of Bi₂O₃ under environmental conditions. The final products had a thermal stability of 210°C, an average particle size distribution of 85 nm, and a surface area of 783 m²/g. The high thermodynamic stability of Bi₂O₃ nanostructures was confirmed by TG and differential scanning calorimetry (DSC) analyses. The nanostructure nature of compounds, and most importantly, the use of an effective, cost-effective, and rapid synthesis route of microwave have created significant physiochemical properties in the Bi₂O₃ products. These unexpected properties have made the possibility of potential application of these products in various fields, especially in nano-catalyst applications. It is well-documented that, as Lewis acid, bismuth nano-catalyst exhibits a great catalytic activity for the green synthesis of some bio-active barbituric acid derivatives using precursors with electron-donating or electron-withdrawing nature in high yields (80%–98%). After incorporating this catalyst into the aqueous media, all the reactions were completed within 2–3 min at room temperature. The main advantages of this method are practical facility, the availability of starting materials, and low costs besides the catalyst reusability. Additionally, the catalyst synthesis process may be carried out in the aqueous media for a short period with medium to high yields. The obtained results have opened a new window for the development of a novel nano-catalyst with practical application.

Antibacterial and antioxidant assay of novel heteroaryl-substituted methane derivatives synthesized via ceric ammonium nitrate (CAN) catalyzed one-pot green approach

Individually, hydroxycoumarin and amino pyrimidine derivatives are of significant biological interest owing to their importance in drugs and pharmaceuticals. To access their combined biological impact into one molecule, we designed a novel, one-pot green approach for synthesizing trisubstituted methanes. A series of new heteroaryl-substituted methanes have been synthesized and subjected to in vitro antibacterial and antioxidant evaluation. Tests against clinical isolates of Escherichia coli (gram-negative) and Staphylococcus aureus showed potent activity of the derivatives 4a, 4b, 4d, 4e, 4f, 4l, and 5 against the former, and 4a, 4e, 4j, and 4l against the later one. Further, antioxidant assay for these TRSMs was also studied where 4a, 4b, 4f, 4j, and 4l exhibited the most promising results. These preliminary bioassay evaluations strongly suggest the promise and scope of these molecules in medical science. A one pot methodology for the synthesis of coumarin and uracil tethered trisubstituted methanes has been reported. The synthesized derivatives were further analyzed for their antibacterial and antioxidant properties to explore their medicinal applications. The salient features of this methodology are operational simplicity, short reaction time, good to moderate yields of the products, easy purification method. Biochemical assay of the synthesized TRSMs a reveals their utility in medicinal & pharma industry.

Genotoxicity assessment of four novel quinazoline-derived trypanocidal agents in the Drosophila wing somatic mutation and recombination test

Chagas disease, caused by the protozoan Trypanosoma cruzi, has increased in the world due to migration, travelling and climate change; at present, the principal problem is that common trypanocidal agents have resulted in toxic or inconvenient side effects. We tested for genotoxicity in the standard (ST) and high bioactivation (HB) crosses of Drosophila wing somatic mutation and recombination test, four novel trypanocidal agents derived from 2, 4, 6-triaminquinazoline (TAQ): 2,4-diamino-6 nitro-1,3 diazonaftalene (S-1QN2-1), 2,4-diacetamino-6-amino 1,3 diazonaftalene (D-1), N6-(4,methoxybenzyl)quinazoline-2,4,6-triamine (GHPM) and N6-[4-(trifluoromethoxy)benzyl]quinazoline-2,4,6-triamine (GHPMF) at 1.9, 3.9, 7.9 and 15 µM, respectively. Also, high-pressure liquid chromatography (HPLC) analysis was run to determine the remanence of either drug in flare, and Oregon R(R)-flare flies emerged from treated larvae. S-1QN2-1 showed genotoxicity only in the ST cross, increasing the small, large and total spot frequencies at all concentrations and twin spots only at 1.9 µM; D-1 and GHPM showed significant increments of large spots only at 15 µM in the ST cross; GHPMF was not genotoxic at any concentration or either cross. In the mwh clones accumulated distribution frequencies analysis, associated with disrupted cell division, S-1QN2-1 caused alterations in the ST cross at all concentrations but only at 15 µM in the HB cross; D-1 caused alterations at 3.9, 7.9 and 15 µM in the ST cross and at 1.9 and 15 µM in the HB cross; GHPM caused alterations at 7.9 and 15 µM in the ST cross and also at 1.9, 3.9 and 7.9 µM in the HB cross; GHPMF caused those alterations at all concentrations in the ST cross and at 1.9, 3.9 and 7.9 µM in the HB cross. The HPLC results indicated no traces of either agent in the flare and Oregon R(R)-flare flies. We conclude that S-1QN2-1 is clearly genotoxic, D-1 and GHPM have an unclear genotoxicity and GHPMF was not genotoxic; all quinazoline derivatives disrupted cell division. GHPMF is a good candidate to be tested in other genotoxicity and cytotoxic bioassays. The differences in the genotoxic activity of these trypanocidal agents are correlated with differences in their chemical structure.

Synthesis, biological activity and POM/DFT/docking analyses of annulated pyrano[2,3-d]pyrimidine derivatives: Identification of antibacterial and antitumor pharmacophore sites

New annulated pyrano[2,3-d]pyrimidine derivatives were synthesized with hydroxyl, methoxy, bromine, nitrile and nitro substituents on its skeleton. The correlated electronic effect of substituents on the magnitude of antibacterial activity was noted. The electron donating substituents (namely; 4-OH, 4-OCH₃, 4-Br) and electron withdrawing substituents (4-NO₂) on phenyl ring in the pyrano[2,3-d]pyrimidine skeleton exerted different influence on its antimicrobial activity against some Gram-positive and Gram-negative bacteria such as Pseudomonas aureus, E. coli, Staphylococcus aureus, Klebsiella pneumonia and Bacillus cereus. All the pyrano[2,3-d]pyrimidines were characterized by spectroscopic analyses. Antibacterial screening revealed that the presence of heteroaryl, cyano and amino groups on pyrano[2,3-d]pyrimidine skeleton increases its penetrating power on the bacterial cell wall so that the product becomes more biologically active. So the the nature of electron withdrawing or electro-donnor Impact of substituents should be taken in consideration in drug design. Hydrolysis of -CRN to amide restored vital Intramolecular interaction like ortho-nitrophenyl and ONO^δ-…NH^δ+/amide link, offering a crucial template for antibacterial NH, HO-pharmacophore sites, which ultimately elevated innate antimicrobial profiles. POM combinatorial analysis of tangible electronic contributions due to armed annulated pyrano[2,3-d]pyrimidines concluded their broad antimicrobial activity and viable/prominent drug score index through perspective parameters particularly: inter atomic distance/linkers, steric, electronic, polar parameters, and with a different polarising effect of electron donating/withdrawing environments of substituents. Furthermore, an anti-Kinase pharmacophore site (OCNHCO) was evaluated in continuation of the POM investigations. All synthesized products verified fewer side effects than standard streptomycin, but facile implication in selective cancer media (viz. breast or leucemia still needs to be screened).

Design, Synthesis, and Quantum Chemical Calculations of 2,6-Diphenylspiro[cyclohexane-1,3’-pyrido[1,2-a]pyrimidine]-2’,4,4’-trione through DFT approach

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Structural elucidation of synthesized 2,6-diphenylspiro[cyclohexane-1,3’-pyrido[1,2- a]pyrimidine]-2’,4,4’-trione has been done by UV, FT-IR, 1H, 13C NMR and mass spectroscopy. The molecule was further subjected to density functional theory (DFT) studies with B3LYP function using 6-31G(d,p) basis atomic set. The title molecule was investigated on the basis of thermodynamic properties, polarizability, hyperpolarizability, intermolecular interactions, HOMO and LUMO energy values, MESP, ESP and NBO computations to correlate experimental results with in-silico studies.

One pot multi-component synthesis of functionalized spiropyridine and pyrido[2,3-d]pyrimidine scaffolds and their potent in-vitro anti-inflammatory and anti-oxidant investigations

A new series of functionalized fused pyridines 4(a-i) and fused pyrido[2,3-d]pyrimidines 8(a-c) were designed and synthesized through a multi-component reaction where in pyridine ring formation step plays a key role. All the newly formed compounds were well characterized by spectral techniques such as FTIR, ¹ HNMR, ¹³ CNMR, HRMS and XRD. The potential therapeutic activities such as anti-inflammatory activity by protein denaturation and RBC membrane stabilization methods, and anti-oxidant activity by DPPH scavenging method of the newly synthesized compounds were studied. Interestingly, in-vitro testing of these compounds reveals that the compounds 4d, 4g, 4i, 8a and 8b showed comparable anti-inflammatory activity with respect to the standard drug, diclofenac. Similarly, fused pyridine 4f showed excellent anti-oxidant activity when compared with the standard, ascorbic acid.

The introduction of two new imidazole-based bis-dicationic Brönsted acidic ionic liquids and comparison of their catalytic activity in the synthesis of barbituric acid derivatives

Two bis-dicationic acidic ionic liquids are prepared, used and compared in the synthesis of barbituric acid derivatives.

Chemoselective One-Pot Synthesis of Functionalized Amino-azaheterocycles Enabled by COware

Functionalized bicyclic amino-azaheterocycles are rapidly accessed in a one-pot cross-coupling/reduction sequence enabled by the use of COware. Incompatible reagents are physically separated in a single reaction vessel to effect two chemoselective transformations-Suzuki-Miyaura cross-coupling and heteroarene reduction. The developed method allows access to novel heterocyclic templates, including semisaturated Hedgehog and dual PI3K/mTOR inhibitors, which show enhanced physicochemical properties compared to their unsaturated counterparts.

Bis[(l)prolinate-N,O]Zn: A water-soluble and recycle catalyst for various organic transformations

Under the green chemistry perspective, bis[(l)prolinate-N,O]Zn (also called zinc-proline or Zn[(l)-pro]₂) has proven its competence as a promising alternative in a plethora of applications such as catalyst or promoter. Owing to its biodegradable and non-toxic nature of bis[(l)prolinate-N,O]Zn, it is being actively investigated as a water soluble green catalyst for synthetic chemistry. Bis[(l)prolinate-N,O]Zn are readily utilized under mild conditions and have high selectivity and reactivity with broad range of substrate acceptance to make it better reaction medium for a wide variety of organic transformations. This Review summarizes the till date literature on its synthesis, characterization, and its catalytic role in various organic reactions.

Inorganic-organic hybrid silica based tin complex as a novel, highly efficient and recyclable heterogeneous catalyst for the one-pot preparation of spirooxindoles in water

In the present study, a tin complex immobilized on silica gel as a novel, green, highly efficient and heterogeneous reusable catalyst was synthesized by grafting 2-amino benzamide onto the silica gel surface as a result of the reaction between isatoic anhydride and 3-aminopropyl-functionalized silica gel, followed by complexing with tin chloride. The resulting organic-inorganic hybrid material was evaluated in the one-pot three-component synthesis of spiro[indoline-pyrazolo[4',3':5,6]pyrido[2,3-d]pyrimidine]trione derivatives in water via the condensation reaction of isatins, barbituric acids, and 1H-pyrazol-5-amines. All the reactions were completed in short reaction times and all the products were obtained in high to excellent yields with high purity. In addition, the synthesized novel catalyst could be separated from the reaction mixture by simple filtration and can be reused up to seven runs without significant loss in activity.

Poly(N-bromo-N-ethyl-benzene-1,3-disulfonamide) and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide as new efficient reagents for one-pot synthesis of furano and pyrano pyrimidinones (thiones)

We have developed an efficient procedure for the synthesis of furano and pyrano pyrimidinones (thiones) using PBBS and TBBDA as new reagents.

Mn doped ZrO2 as a green, efficient and reusable heterogeneous catalyst for the multicomponent synthesis of pyrano[2,3-d]-pyrimidine derivatives

A simple and an efficient method has been developed for the one-pot multicomponent synthesis of pyrano[2,3-d]-pyrimidine derivatives.

Microwave assisted one-pot catalyst free green synthesis of new methyl-7-amino-4-oxo-5-phenyl-2-thioxo-2,3,4,5-tetrahydro-1H-pyrano[2,3-d]pyrimidine-6-carboxylates as potent in vitro antibacterial and antifungal activity

An efficiently simple protocol for the synthesis of methyl 7 amino-4-oxo-5-phenyl-2-thioxo-2, 3, 4,5-tetrahydro-1H-pyrano[2,3-d]pyrimidine-6-carboxylates via one-pot three component condensation pathway is established via microwave irradiation using varied benzaldehyde derivatives, methylcyanoacetate and thio-barbituric acid in water as a green solvent. A variety of functionalized substrates were found to react under this methodology due to its easy operability and offers several advantages like, high yields (78–94%), short reaction time (3–6 min), safety and environment friendly without used any catalyst. The synthesized compounds (4a–4k) showed comparatively good in vitro antimicrobial and antifungal activities against different strains. The Compounds 4a, 4b, 4c, 4d 4e and 4f showed maximum antimicrobial activity against Staphylococcus aureus, Bacillus cereus (gram-positive bacteria), Escherichia coli, Klebshiella pneumonia, Pseudomonas aeruginosa (gram-negative bacteria). The synthesized compound 4f showed maximum antifungal activity against Aspergillus Niger and Penicillium chrysogenum strains. Streptomycin is used as standard for bacterial studies and Mycostatin as standards for fungal studies. Structure of all newly synthesized products was characterized on the basis of IR, ¹H NMR, ¹³C NMR and mass spectral analysis.

Electrogenerated base-promoted synthesis of 5-aryl-5,6-dihydro-2H-pyrano[2,3-d]pyrimidine-2,4,7-triones by multicomponent assembly of barbituric acid, aldehydes and Meldrum's acid at room temperature

An electrochemical strategy for the synthesis of pyrano[2,3-d]pyrimidine-2,4,7-triones via a one-pot, three component condensation is described.