Synthesis and Antimicrobial Assessments of Some Quinazolines and Their Annulated Systems

2017 ◽  
Vol 41 (2) ◽  
pp. 106-111 ◽  
Author(s):  
Magdy M. Hemdan ◽  
Ahmed S.A. Youssef ◽  
Fatma A. El-Mariah ◽  
Heba E. Hashem
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
New Products ◽  
Pathogenic Fungi ◽  
Minimal Inhibitory Concentrations ◽  
New Compounds ◽  
Derivatives Of

The syntheses of some new derivatives of quinazoline and their annulated derivatives are described in this work. Investigation of antimicrobial activity of the new products was evaluated using agar well diffusion methods with determination of minimal inhibitory concentrations against six pathogenic bacteria and three pathogenic fungi. Most of the new compounds are potent as antimicrobial agents.

scholarly journals ANTIMICROBIAL ACTIVITIES OF SUCCESSIVE SOLVENT EXTRACTS OF ALBIZIA LEBBECK AND SOLANUM SEAFORTHIANUM AGAINST SOME HUMAN PATHOGENIC MICROORGANISMS

2019 ◽  
pp. 294-296
Author(s):  
HOSUR NARAYANAPPA VENKATESH ◽  
DEVIHALLI CHIKKAIAH MOHANA
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Negative Impact ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Albizia Lebbeck ◽  
Minimal Inhibitory Concentrations ◽  
Broth Dilution

Objective: The continuous emergence of multidrug resistance bacteria and yeast, and the negative impact of synthetic preservatives have led to an increased interest in the use of plant extracts as alternative antimicrobial agents. In the present investigation, the antimicrobial activity of successive solvent extracts of Albizia lebbeck and Solanum seaforthianum has been evaluated against human pathogenic bacteria and yeast. Methods: The disc diffusion method was employed for determination of the zone of inhibitions (ZOIs) and twofold broth dilution technique was employed for determination of minimal inhibitory concentrations, and minimal bactericidal/fungicidal concentrations. Results: Among the successive solvent extracts tested, methanol extracts of both A. lebbeck and S. seaforthianum showed highest antibacterial activity with ZOIs ranged between 10.0 and 20.4 mm at 1 mg/disc followed by ethanol (ZOIs 8.1–17.6 mm). The petroleum ether, toluene, and chloroform extracts showed the least activity. The highest activity was observed against Streptococcus faecalis, whereas the least activity was observed against Pseudomonas aeruginosa. Conclusion: The broad-spectrum antimicrobial activity of methanol extract of A. lebbeck and S. seaforthianum could be explored as antimicrobial agents for the management of pathogenic bacteria and yeast.

scholarly journals Synthesis, characterization and microbial screening of some new methyl 4, 6-o-(4-methoxybenzylidene)-?-D-glucopyranoside Derivatives

2014 ◽  
Vol 37 (2) ◽  
pp. 145-158 ◽  
Author(s):  
Sarkar MA Kawsar ◽  
Abul K MS Kabir ◽  
Mohammad M R Bhuiyan ◽  
Jannatul Ferdous ◽  
Mohammad S Rahman
Keyword(s):  
Pathogenic Bacteria ◽  
Pathogenic Fungi ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
Additional Information ◽  
Fungal Phytopathogens ◽  
New Compounds ◽  
Academy Of Sciences ◽  
Derivatives Of

Regioselective pentanoylation of methyl 4,6-O-(4-methoxybenzylidene)-?-D-glucopyranoside by the direct acylation method provided the methyl 4,6-O-(4-methoxybenzylidene)-2-O-pentanoyl- ?-D-glucopyranoside in good yield. A number of 3-O-acyl derivatives of this 2-O-pentanoylation product were also prepared in order to obtain new compounds and also gather additional information for structure elucidation. The chemical structure of the newly synthesized compounds was characterized by analytical and spectral methods. Synthesized acylated derivatives of Dglucopyranoside were screened for in vitro antimicrobial activities against ten human pathogenic bacteria and four plant pathogenic fungi. The study revealed that the acylated products exhibited moderate to good antimicrobial activities. It was interesting to observe that the selected compounds were more sensitive against fungal phytopathogens than those of the bacterial strains. DOI: http://dx.doi.org/10.3329/jbas.v37i2.17554 Journal of Bangladesh Academy of Sciences, Vol. 37, No. 2, 145-158, 2013

scholarly journals Synthesis and Antimicrobial Activity of Calycanthaceous Alkaloid Analogues

2016 ◽  
Vol 11 (10) ◽  
pp. 1934578X1601101
Author(s):  
Shaojun Zheng ◽  
Longbo Li ◽  
Yu Wang ◽  
Rui Zhu ◽  
Hogjin Bai ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Structural Modification ◽  
Antimicrobial Agents ◽  
Pathogenic Fungi ◽  
Curvularia Lunata ◽  
Plant Pathogenic Fungi ◽  
H Nmr ◽  
High Degree ◽  
Derivatives Of ◽  
C Nmr

A series of 24 novel derivatives of the calycanthaceous alkaloids with a tetrahydropyrroloindol-based core structure was synthesized from tryptophan in good yields. Their structures were characterized by IR, 1H NMR, and 13C NMR spectroscopy and ESI-MS. The synthesized compounds were evaluated against a wide variety of plant pathogenic fungi. Compound a9 exhibited a high degree of activity against Curvularia lunata, with 91.0% activity at a concentration of 100 μg mL−1 and with an EC50 of 44.6 μg mL−1. a7, a8, a13, and a17 exhibited high degrees of activity against Sclerotinia sclerotiorum, with a8 being the most effective with an EC50 of 38.4 μg mL−1. Compound a9 illustrated activity against Botrytis cinerea, with an EC50 of 79.5 μg mL−1. Considering the compounds evaluated, the alkyl substituents of the chain may contribute to the significant variations in fungicidal potency. The structure antifungal activity relationships are also discussed. These results will pave the way for further design, structural modification, and development of calycanthaceous alkaloids as antimicrobial agents.

scholarly journals Novel Derivatives of 4-Methyl-1,2,3-Thiadiazole-5-Carboxylic Acid Hydrazide: Synthesis, Lipophilicity, and In Vitro Antimicrobial Activity Screening

2021 ◽  
Vol 11 (3) ◽  
pp. 1180
Author(s):  
Kinga Paruch ◽  
Łukasz Popiołek ◽  
Anna Biernasiuk ◽  
Anna Berecka-Rycerz ◽  
Anna Malm ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Carboxylic Acid ◽  
Bacterial Infections ◽  
Acid Hydrazide ◽  
Antimicrobial Effect ◽  
In Vitro Antimicrobial Activity ◽  
Research Goal ◽  
New Compounds ◽  
Derivatives Of

Bacterial infections, especially those caused by strains resistant to commonly used antibiotics and chemotherapeutics, are still a current threat to public health. Therefore, the search for new molecules with potential antimicrobial activity is an important research goal. In this article, we present the synthesis and evaluation of the in vitro antimicrobial activity of a series of 15 new derivatives of 4-methyl-1,2,3-thiadiazole-5-carboxylic acid. The potential antimicrobial effect of the new compounds was observed mainly against Gram-positive bacteria. Compound 15, with the 5-nitro-2-furoyl moiety, showed the highest bioactivity: minimum inhibitory concentration (MIC) = 1.95–15.62 µg/mL and minimum bactericidal concentration (MBC)/MIC = 1–4 µg/mL.

scholarly journals The Design of Alapropoginine, a Novel Conjugated Ultrashort Antimicrobial Peptide with Potent Synergistic Antimicrobial Activity in Combination with Conventional Antibiotics

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 712
Author(s):  
Ali Salama ◽  
Ammar Almaaytah ◽  
Rula M. Darwish
Keyword(s):  
Antimicrobial Activity ◽  
Hemolytic Activity ◽  
Antimicrobial Agents ◽  
Antimicrobial Activities ◽  
Resistant Bacteria ◽  
Human Red Blood Cells ◽  
Drug Resistant Bacteria ◽  
Different Strains ◽  
Conventional Antibiotics

(1) Background: Antimicrobial resistance represents an urgent health dilemma facing the global human population. The development of novel antimicrobial agents is needed to face the rising number of resistant bacteria. Ultrashort antimicrobial peptides (USAMPs) are considered promising antimicrobial agents that meet the required criteria of novel antimicrobial drug development. (2) Methods: Alapropoginine was rationally designed by incorporating arginine (R), biphenylalanine (B), and naproxen to create an ultrashort hexapeptide. The antimicrobial activity of alapropoginine was evaluated against different strains of bacteria. The hemolytic activity of alapropoginine was also investigated against human erythrocytes. Finally, synergistic studies with antibiotics were performed using the checkerboard technique and the determination of the fractional inhibitory index. (3) Results: Alapropoginine displayed potent antimicrobial activities against reference and multi-drug-resistant bacteria with MIC values of as low as 28.6 µg/mL against methicillin-resistant S. aureus. Alapropoginine caused negligible toxicity toward human red blood cells. Moreover, the synergistic studies showed improved activities for the combined conventional antibiotics with a huge reduction in their antimicrobial concentrations. (4) Conclusions: The present study indicates that alapropoginine exhibits promising antimicrobial activity against reference and resistant strains of bacteria with negligible hemolytic activity. Additionally, the peptide displays synergistic or additive effects when combined with several antibiotics.

Screening of Antimicrobial Activity and Cytotoxic Effects of Two Cladonia Species

2013 ◽  
Vol 68 (5-6) ◽  
pp. 191-197 ◽  
Author(s):  
Birkan Açıkgöz ◽  
İskender Karaltı ◽  
Melike Ersöz ◽  
Zeynep M. Coşkun ◽  
Gülşah Çobanoğlu ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Activities ◽  
Chloroform Extract ◽  
Cytotoxic Effects ◽  
Minimal Inhibitory Concentrations ◽  
E Coli ◽  
Methanol Extracts ◽  
Gram Positive Bacteria

The present study explores the antimicrobial activity and cytotoxic effects in culture assays of two fruticose soil lichens, Cladonia rangiformis Hoffm. and Cladonia convoluta (Lamkey) Cout., to contribute to possible pharmacological uses of lichens. In vitro antimicrobial activities of methanol and chloroform extracts against two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), two Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus), and the yeast Candida albicans were examined using the paper disc method and through determination of minimal inhibitory concentrations (MICs). The data showed the presence of antibiotic substances in the chloroform and the methanol extracts of the lichen species. The chloroform extracts exhibited more signifi cant antimicrobial activity than the methanol extracts. However, a higher antifungal activity was noted in the methanol extract of C. rangiformis. The maximum antimicrobial activity was recorded for the chloroform extract of C. convoluta against E. coli. The cytotoxic effects of the lichen extracts on human breast cancer MCF-7 cells were evaluated by the trypan blue assay yielding IC50 values of ca. 173 and 167 μg/ml for the extracts from C. rangiformis and C. convoluta, respectively.

Antimicrobial Activity of Fractions and Compounds from Calophyllum brasiliense (Clusiaceae/Guttiferae)

2004 ◽  
Vol 59 (9-10) ◽  
pp. 657-662 ◽  
Author(s):  
Juliana B. Pretto ◽  
Valdir Cechinel-Filho ◽  
Vânia F. Noldin ◽  
Mara R. K. Sartori ◽  
Daniela E. B Isaias ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Protocatechuic Acid ◽  
Inhibitory Concentration ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Methanolic Extracts ◽  
Calophyllum Brasiliense

Abstract Calophyllum brasiliense (Clusiaceae/Guttiferae) is a native Brazilian medicinal plant traditionally used against several diseases, including infectious pathologies. Crude methanolic extracts (CME) and two fractions, denoted non-polar (soluble in chloroform) and polar (nonsoluble in chloroform), were prepared from different parts of the plant (roots, stems, leaves, flowers and fruits) and studied. The following compounds were isolated and tested against pathogenic bacteria and yeasts by determination of the minimal inhibitory concentration (MIC): brasiliensic acid (1), gallic acid (2), epicatechin (3), protocatechuic acid (4), friedelin (5) and 1,5-dihydroxyxanthone (6). The results indicated that all the parts of the plant exhibited antimicrobial activity against Gram-positive bacteria, which are selectively inhibited by components of C. brasiliense. No activity was observed against Gram-negative bacteria and yeasts tested. Regarding the isolated compounds, substance 4 showed antimicrobial activity against all the tested microorganisms, whereas compound 6 exhibited antimicrobial activity only against Gram-positive bacteria. The results from the current study confirm and justify the popular use of this plant to treat infectious processes.

scholarly journals Synthesis and Antimicrobial Activity of Silver-Doped Hydroxyapatite Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Carmen Steluta Ciobanu ◽  
Simona Liliana Iconaru ◽  
Mariana Carmen Chifiriuc ◽  
Adrian Costescu ◽  
Philippe Le Coustumer ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Antibacterial Properties ◽  
Major Health Problem ◽  
Major Health ◽  
Wall Structures ◽  
Nanocrystalline Hydroxyapatite ◽  
Qualitative Assay ◽  
Antibacterial And Antifungal

The synthesis of nanosized particles of Ag-doped hydroxyapatite with antibacterial properties is of great interest for the development of new biomedical applications. The aim of this study was the evaluation ofCa10−xAgx(PO4)6(OH)2nanoparticles (Ag:HAp-NPs) for their antibacterial and antifungal activity. Resistance to antimicrobial agents by pathogenic bacteria has emerged in the recent years and became a major health problem. Here, we report a method for synthesizing Ag doped nanocrystalline hydroxyapatite. A silver-doped nanocrystalline hydroxyapatite was synthesized at 100°C in deionised water. Also, in this paper Ag:HAp-NPs are evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria and fungal strains. The specific antimicrobial activity revealed by the qualitative assay is demonstrating that our compounds are interacting differently with the microbial targets, probably due to the differences in the microbial wall structures.

Research on Antimicrobial Activity of Functional Protein Films

2013 ◽  
Vol 785-786 ◽  
pp. 660-665 ◽  
Author(s):  
Zhi Ying Huang ◽  
Qiao Lei ◽  
Jian Qiang Bao ◽  
Qian Nan Xun
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Antimicrobial Effect ◽  
Potassium Sorbate ◽  
Protein Films ◽  
Functional Protein ◽  
Elongation At Break ◽  
Mechanical And Physical Properties

Antimicrobial effect of functional protein films incorporating garlic oil (GO), potassium sorbate (PS) and nisin (N) at various concentrations were discussed. This activity was tested against food pathogenic bacteria namely Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus).Mechanical and physical properties were characterized. In the range of antimicrobial agents concentration studied, tensile strength (TS) and elongation at break (E) of functional protein films were changed by incorporating GO,PS and N. And the WVP value of functional protein films decreased as antimicrobial agents added. GO incorporated into protein films had no effect on E.coli, but incorporation of GO at 300μl had antimicrobial activity against S.aureus. Protein films incorporated with PS showed antimicrobial activity against S.aureus, but there was no effect on E.coli. Incorporation of N at the lowest level of 25,000 IU had antimicrobial activity against both E.coli and S.aureus.

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