scholarly journals Synthesis, Antimicrobial Evolution, Defibrillation Threshold Studies, Docking Studies, Silico Admet Analysis and PER-Metabolism Study of Some New Dihydropyrmidine Derivatives

2020 ◽  
Vol 10 (01) ◽  
pp. 21-32
Author(s):  
Sahar B. Al-Juboori

Dihydropyrimidinone and dihydropyrimidine derivatives are reported to possess broad biological activities. Many synthetic samples have been studied as antibacterial, antiviral, and anticancer agents. We decided to synthesize novel compounds of new pyrimidine derivatives. The present work involves the synthesis of new dihydropyridine derivatives. The starting vanillin, compound (1) was used as the key intermediate to prepare the 5-acetyl-4-(4-hydroxy-3-methoxyphenyl)-6-methyl pyrimidine-2(1H)-one(2),Ethyl 4-(4-hydroxy-3-methoxyphenyl)-6-methyl-2-oxo-1,2-dihydropyrimidine-5-carboxylate (3), 4-(4-hydroxy-3-methoxyphenyl)-5,6,7,8-tetrahydro quinazoline-2(1H)-one (4), respectively, through the reaction with urea and acetylacetone or ethyl acetoacetate or cyclohexanone but 4-(4-hydroxy-3-methoxyphenyl)-5,6,7,8-tetrahydro quinazoline-2(1H)-thione (5) reacted with thiourea and cyclohexanone. FTIR,1H-NMRand13C-NMR spectroscopy characterized all the synthesized compounds. The synthesized derivatives were screened for their in vitro, antibacterial activity against two gram-positive bacteria: Bacillus subtilis, and Staphylococcus aureus and two gram-negative bacteria: Klebsiella pneumonia and Salmonella typhi and the results showed that most of them have good antibacterial activity. While their antifungal activity against three fungi species: (Aspergillus fumigates, Aspergillus niger, and Rhizopus), revealed that compounds (1-5) displayed the most potent antifungal activity. Density functional theory ( DFT) calculations for the synthesized compounds (1-5) were conducted, using a molecular structure with optimized geometry. Highest occupied molecular orbital/lowest unoccupied molecular orbital energies and structures are demonstrated. The antimicrobial activity indicates that compounds 3 and 4 are the most active than the compounds 2 and 5. Molecular docking revealed that compounds (4) and (5), with cyclohexyl groups are important to block the active centers of glucose -6-phosphate synthase in the bacteria and fungi.

Author(s):  
SAHAR B. AL-JUBOORI ◽  
AMMAR A. RAZZAK MAHMOOD

Objective: Pyrimidine derivatives are reported to possess antibacterial, antifungal, anticancer, and anticonvulsant activities. Encouraged by this remarks, we decided to synthesize novel compounds of new 2-macraptopyrimidine linked to Schiffs̕ bases. Methods: The present work involves the synthesis of new 2-mercaptopyrimidine linked to Schiffs̕ bases. The starting, 2-mercaptopyrimidine, compound (1) reacted with thiourea to afford the corresponding 1-(pyrimidin-2-yl) thiourea (2). Then compound (2) was used as the key intermediate to prepare the -1-(2-hydroxy benzylidene)-3-(pyrimidin-2-yl) thiourea (3), and (1-benzylidine)-3-(pyrimidin-2-yl) thiourea (4), through the reaction with 2-hydroxybenzaldehyde, and benzaldehyde, respectively. Results: All the synthesized compounds were characterized by Fourier-transform infrared and1H-nuclear magnetic resonance spectroscopy. The synthesized derivatives were screened for their in vitro, antibacterial activity against two Gram-positive bacteria: Bacillus subtilis and Staphylococcus aureus and four Gram-negative bacteria: Klebsiella pneumoniae, Escherichia coli, and Salmonella typhi, and the results showed that most of them have good antibacterial activity. While their antifungal activity against three fungi species (Aspergillus fumigates, Aspergillus niger, Aspergillus terrus and Rhizopus) revealed that compounds (2-4) displayed the most potent antifungal activity. Density functional theory (DFT) calculations for the synthesized 2-mercapto pyrimidine derivatives were conducted, using a molecular structure with optimized geometry. Highest occupied molecular orbital/lowest unoccupied molecular orbital energies and structures are demonstrated. Conclusion: The antimicrobial activity indicates that compounds (3) and (4) are the most active than the compounds (1) and (2). Molecular docking revealed that compounds (3) and (4), with bulky phenyl groups are essential to blocking the active centers of glucose -6-phosphate synthase in the bacteria and fungi.


Author(s):  
Nedaa A. Hameed A. Rahim ◽  
Sumayah Saadi Abbas ◽  
Sahar B. Aljuboori ◽  
Ammar A Razzak Mahmood

Objective: Benzoxazole derivatives have antifungal, anticancer, antibacterial, and anticonvulsant function. Encouraged by this comment, we agreed to synthesize new Benzoxazole compounds connected to the bases of Schiff's. Methods: 2,4-diaminophenol (1) was prepared by the reaction of 2,4-dinitrophenol and sodium dithionate. Compound (1) reacted with either acetic acid to afford compound (2) or with formic acid to afford compound (3). The Schiff bases were preparation from the reaction condensing reaction of compound (2) or (3) and aromatic aldehydes or ketone; [p-nitrobenzaldehyde, p-hydroxybenzaldehyde, p-chlorobenzaldehyde, p-bromoacetophenone and terephthaldehyde]. Results: FTIR and 1H-NMR spectroscopy characterized all of the preparation compounds. The synthesized derivatives against (Gram positive bacteria GPB) (Bacillus subtilis) and two (Gram-negative bacteria GNB) (Klebsiella pneumoniae and Escherichia coli) and (one fungal species Candida albicans), have been evaluated to their antibacterial activity in vitro. all results showed which most of them have good antibacterial activity, while their antifungal activity revealed that compounds displayed slight antifungal activity. The synthesized Benzoxazole derivatives were docked using, glucosamine 6-phosphate synthase as a ligand. Conclusion: The antimicrobial activity indicates that compounds (4), (7) and (8) have more potent antibacterial activity than the compounds (5) and (6). Molecular docking study revealed that compounds (7) and (8), with bulky phenyl groups are essential to block the active centers of (GluN-6-Ps) amino acids synthase in the bacteria.


Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3038
Author(s):  
Ramesh ◽  
Rao ◽  
Hong ◽  
Reddy

A series of 2-hydroxy-3-chrysino dithiocarbamate derivatives (3a–k) were designed, synthesized, and characterized for their structure determination by 1H NMR, 13C NMR, and HRMS (ESI) spectral data. They were screened for their in vitro biological activities against a panel of selected bacterial and fungal strains. These antimicrobial studies indicate that some of the analogues manifested significant activity compared to standard drugs. Among the synthetic analogues (3a–k), compounds 3d, 3f, and 3j exhibited very good antibacterial activity and compounds 3d, 3f, and 3h showed very good antifungal activity compared to the standard drugs penicillin and itrazole, respectively. The compounds 3e, 3g, and 3h showed moderate antibacterial activity and the compounds 3j and 3k showed moderate antifungal activity. Molecular docking studies were performed and the experimental antimicrobial screening results were also correlated with the binding energy values obtained by molecular docking. The synthesized chrysin analogues (3a–k) have obeyed Lipinski’s “rule of five” and have drug-likeness.


2020 ◽  
Vol 16 (3) ◽  
pp. 363-367
Author(s):  
Aina N. Shiyanga ◽  
Michael Knott ◽  
Petrina Kapewangolo

Background: The marine red alga Plocamium naturally produces halogenated monoterpenes with varied biological activities. In our continuing efforts to discover new lead compounds for the treatment of HIV/AIDS as well as novel antibacterial compounds, various Namibian Plocamium species have been investigated. Methods: A rare but known compound namely 1E,3R,4S,5E,7Z-1-bromo-3,4,8-trichloro-7- (dichloromethyl)-3-methylocta-1,5,7-triene (1) was isolated from a Namibian Plocamium red alga. The anti-HIV activity of compound 1 was investigated against three HIV enzymes namely, HIV protease, reverse transcriptase and integrase. In addition, compound 1 was also screened for antibacterial activity against selected microbes using the disc diffusion method. Results: Compound 1 demonstrated selective in vitro inhibition against HIV-1 integrase with a 50% inhibition concentration of <0.06 mM. Weak inhibitory activity was observed against HIV-1 reverse transcriptase and protease. Compound 1 also showed antibacterial activity against Staphylococcus aureus (ATCC 25923), Alcaligenes faecalis (ATCC 8750) and Serratia marcescens (ATCC 8100) with MIC values of 0.65 mM, and 1.29 mM for Klebsiella pneumonia (ATCC 13883). Conclusion: The results of this study highlight the potential of halogenated monoterpenes from red seaweed as possible leads in the development of new anti-HIV and antimicrobial pharmaceuticals.


2019 ◽  
Vol 19 (10) ◽  
pp. 1285-1292 ◽  
Author(s):  
Kuldip D. Upadhyay ◽  
Anamik K. Shah

Background: Quinoline analogues exhibited diversified biological activities depending on the structure type. A number of natural products with pyrano[3,2-c]quinolone structural motifs and patented chromenes were reported as promising cytotoxic agents. Objective: The present study is aimed to evaluate a new series of pyrano[3,2-c]quinoline scaffolds derived from the fusion of bioactive quinolone pharmacophore with structurally diverse aryl substituted chromene for its cytotoxicity. Methods: A library of pyrano[3,2-c]quinoline analogues was prepared from one-pot multi component synthesis using various aromatic aldehydes, malononitrile and 2,4-dihydroxy-1-methylquinoline. The new synthetics were primarily screened for its cytotoxicity (IC50) against different human cancer cell lines in vitro. The promising synthetics were further evaluated in vitro for their potency against different kinase activity. The promising compounds were finally tested for their in vivo efficacy in SCID type mice HCT-116 tumor model. Results: The screening results revealed that compounds 4c, 4f, 4i and 4j showed promising activity in in vitro study. However, compound 4c was found to be the most potent candidate with 23% tumor growth inhibition in HCT-116 tumor mice model. Conclusion: The structure activity relationship suggested that 3-substitution on the aryl ring at C4 position of the pyrano[3,2 c]quinolone moiety seems to have an important position for cytotoxicity activity. However, 3- chloro substitution at C4 aryl ring showed a significant alteration of the bioactive conformer of the parent scaffold and outcome with compound 4c as the most potent candidate of the series.


2021 ◽  
Vol 22 (6) ◽  
pp. 3253
Author(s):  
Clarisse Roblin ◽  
Steve Chiumento ◽  
Cédric Jacqueline ◽  
Eric Pinloche ◽  
Cendrine Nicoletti ◽  
...  

The world is on the verge of a major antibiotic crisis as the emergence of resistant bacteria is increasing, and very few novel molecules have been discovered since the 1960s. In this context, scientists have been exploring alternatives to conventional antibiotics, such as ribosomally synthesized and post-translationally modified peptides (RiPPs). Interestingly, the highly potent in vitro antibacterial activity and safety of ruminococcin C1, a recently discovered RiPP belonging to the sactipeptide subclass, has been demonstrated. The present results show that ruminococcin C1 is efficient at curing infection and at protecting challenged mice from Clostridium perfringens with a lower dose than the conventional antibiotic vancomycin. Moreover, antimicrobial peptide (AMP) is also effective against this pathogen in the complex microbial community of the gut environment, with a selective impact on a few bacterial genera, while maintaining a global homeostasis of the microbiome. In addition, ruminococcin C1 exhibits other biological activities that could be beneficial for human health, as well as other fields of applications. Overall, this study, by using an in vivo infection approach, confirms the antimicrobial clinical potential and highlights the multiple functional properties of ruminococcin C1, thus extending its therapeutic interest.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Séverine Boisard ◽  
Anne-Marie Le Ray ◽  
Anne Landreau ◽  
Marie Kempf ◽  
Viviane Cassisa ◽  
...  

During this study, thein vitroantifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains:Candida albicans, C. glabrata, andAspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains includingStaphylococcus aureus. Organic extracts showed a significant antifungal activity againstC. albicansandC. glabrata(MIC80between 16 and 31 µg/mL) but only a weak activity towardsA. fumigatus(MIC80= 250 µg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially againstS. aureus(SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC10030–97 µg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.


2015 ◽  
Vol 9 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Muhammad Naeem Iqbal ◽  
Aftab Ahmad Anjum ◽  
Muhammad Asad Ali ◽  
Firasat Hussain ◽  
Shahzad Ali ◽  
...  

The development of resistance in bacteria against commonly used antibiotics/drugs is of considerable medical significance. Aim of this study was to determine the microbial load of un-pasteurized packed fruit juices sold in Lahore city and to determine antibacterial activity of five different honey samples against isolated bacteria. Unpasteurized fruit juice samples (n=60) were collected from street vendors. All the samples were subjected to Total viable count (TVC), Staphylococcal count (SC) and Coliform count (CC). One hundred and ten strains of bacteria were isolated from various fruit juices and identified on the basis of cultural characters, morphology and biochemical characters. Mean TVCs, SCs and CCs of juices (6.80±1.91, 5.45±1.06 and 3.25±1.25 log10 CFU/ml respectively) were non-significant with standard permissible limits (p<0.05). Among all the fruit juices, 66.66% of samples had TVC more than 4 log10 CFU/ml, 51.66% of samples had SC more than 3 log10 CFU/ml and 46.66% of samples had CC more than 2 log10 CFU/ml. Among the bacillus isolates purified, were Bacillus alvei, Bacillus subtilis, Bacillus polymyxa, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli and Enterobecter. All five different types of honey samples used in this study showed antibacterial activity against B. alvei, B. polymyxa, B. subtilis and S. aureus and no activity against P. aeruginosa, K. pneumonia, Enterobecter and E. coli. It is concluded that microbial load in unpasteurized fruit juices is significantly higher than standard permissible limits which insinuates its possible role in spoilage and food borne illnesses. Periodic monitoring of packed fruit juices should be carried out to make them safe for consumption. Honey can be used as an alternative for treatment of various infections, especially those caused by antibiotic resistant bacteria.


2020 ◽  
Vol 13 (12) ◽  
pp. 469
Author(s):  
Sergey N. Lavrenov ◽  
Elena B. Isakova ◽  
Alexey A. Panov ◽  
Alexander Y. Simonov ◽  
Viktor V. Tatarskiy ◽  
...  

The wide spread of pathogens resistance requires the development of new antimicrobial agents capable of overcoming drug resistance. The main objective of the study is to elucidate the effect of substitutions in tris(1H-indol-3-yl)methylium derivatives on their antibacterial activity and toxicity to human cells. A series of new compounds were synthesized and tested. Their antibacterial activity in vitro was performed on 12 bacterial strains, including drug resistant strains, that were clinical isolates or collection strains. The cytotoxic effect of the compounds was determined using an test with HPF-hTERT (human postnatal fibroblasts, immortalized with hTERT) cells. The activity of the obtained compounds depended on the carbon chain length. Derivatives with C5–C6 chains were more active. The minimum inhibitory concentration (MIC) of the most active compound on Gram-positive bacteria, including MRSA, was 0.5 μg/mL. Compounds with C5–C6 chains also revealed high activity against Staphylococcus epidermidis (1.0 and 0.5 μg/mL, respectively) and moderate activity against Gram-negative bacteria Escherichia coli (8 μg/mL) and Klebsiella pneumonia (2 and 8 μg/mL, respectively). However, they have no activity against Salmonella cholerasuis and Pseudomonas aeruginosa. The most active compounds revealed higher antibacterial activity on MRSA than the reference drug levofloxacin, and their ratio between antibacterial and cytotoxic activity exceeded 10 times. The data obtained provide a basis for further study of this promising group of substances.


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