scholarly journals Targeted Isolation of Rubrolides from the New Zealand Marine Tunicate Synoicum kuranui

Marine Drugs ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 337
Author(s):  
Joe Bracegirdle ◽  
Luke J. Stevenson ◽  
Michael J. Page ◽  
Jeremy G. Owen ◽  
Robert A. Keyzers
Keyword(s):  
Natural Products ◽  
Bacillus Subtilis ◽  
New Zealand ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Chemical Space ◽  
Gram Positive Bacteria ◽  
Growth Inhibitory ◽  
Growth Inhibitory Activity ◽  
New Chemical Entities

Global natural products social (GNPS) molecular networking is a useful tool to categorize chemical space within samples and streamline the discovery of new natural products. Here, we demonstrate its use in chemically profiling the extract of the marine tunicate Synoicum kuranui, comprised of many previously reported rubrolides, for new chemical entities. Within the rubrolide cluster, two masses that did not correspond to previously reported congeners were detected, and, following MS-guided fractionation, led to the isolation of new methylated rubrolides T (3) and (Z/E)–U (4). Both compounds showed strong growth inhibitory activity against the Gram-positive bacteria Bacillus subtilis, with minimum inhibitory concentration (MIC) values of 0.41 and 0.91 μM, respectively.

Semisynthetic triazoles as an approach in the discovery of Novel Lead Compounds

2021 ◽  
Vol 25 ◽  
Author(s):  
Pedro Alves Bezerra Morais ◽  
Carla Santana Francisco ◽  
Heberth de Paula ◽  
Rayssa Ribeiro ◽  
Mariana Alves Eloy ◽  
...  
Keyword(s):  
Natural Products ◽  
Medicinal Chemistry ◽  
Chemical Space ◽  
Biological Activities ◽  
Post Translational Modification ◽  
Cellular Processes ◽  
Modern Drug ◽  
New Chemical Entities ◽  
Almost All ◽  
The 19Th Century

: Historically, the medicinal chemistry is concerned with the approach of organic chemistry to new drug synthesis. Considering the fruitful collections of new molecular entities, the dedicated efforts for medicinal chemistry are rewarding. Planning and search of new and applicable pharmacologic therapies involve the altruistic nature of the scientists. Since the 19th century, notoriously the application of isolated and characterized plant-derived compounds in modern drug discovery and in various stages of clinical development highlight its viability and significance. Natural products influence a broad range of biological processes, covering transcription, translation, and post-translational modification and being effective modulators of almost all basic cellular processes. The research of new chemical entities through “click chemistry” continuously opens up a map for the remarkable exploration of chemical space in towards leading natural products optimization by structure-activity relationship. Finally, here in this review, we expect to gather a broad knowledge involving triazolic natural products derivatives, synthetic routes, structures, and their biological activities.

Antimicrobial activities of different parts of two geographically distinct varieties of Jatropha curcas Linn. fruit in Pakistan

2021 ◽  
Vol 50 (2) ◽  
pp. 219-226
Author(s):  
Abdul Haq ◽  
Alam Khan ◽  
Zulfiqar Ali Malik ◽  
Mushtaq Ahmed ◽  
Samiullah Khan ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Minimum Inhibitory Concentration ◽  
Seed Coat ◽  
Jatropha Curcas ◽  
Inhibitory Concentration ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Seed Kernel ◽  
Subtilis Atcc ◽  
Bacillus Subtilis Atcc

Antimicrobial activities of deoiled seed kernel (mechanically pressed), fruit coat and seed coat of Jatropha curcas Linn. collected from two regions (Bannu and Peshawar) of Pakistan were investigated. The antimicrobial activities were carried out against Klebsiella pneumoniae (ATCC 43816), Escherichia coli (ATCC 10536), Staphylococcus aureus (ATCC 6538), Bacillus subtilis (ATCC 6633) and two clinical fungal isolates Aspergillus fumigatus and Candida albicans using agar well diffusion method. The antibacterial activities of Peshawar sample were found to be higher than Bannu, against selected strains. While antifungal activities of both samples were similar. Highest zone of inhibition 31.5 ± 0.7 mm was exhibited by n-hexane extract of deoiled seed kernel of Peshawar sample against Bacillus subtilis (ATCC 6633). The minimum inhibitory concentration of ethanolic extracts of deoiled seed kernel and seed coat of Peshawar sample was 31.25 - 25 mg/ml. Whereas, minimum inhibitory concentration of ethanolic and n-hexane extracts of Bannu sample was 62.5 - 125 mg/ml. The results suggested that antimicrobial potential of J. curcas Linn. varied with geographical distribution. The investigation of different varieties of medicinal plants belonging to the same species will greatly enhance the chances of best pharmaceuticals discovery. Bangladesh J. Bot. 50(2): 219-226, 2021 (June)

scholarly journals Novel Hybrid Chitosan Derivatives and Chalcones Moiety for Some Biological Applications: Synthesis, Characterization, Antimicrobial and Anti Cancer Activity

2018 ◽  
Author(s):  
E. Bagyaraj ◽  
E. Vakees ◽  
M. Aboobucker Sithique
Keyword(s):  
Antimicrobial Activity ◽  
Minimum Inhibitory Concentration ◽  
High Activity ◽  
Inhibitory Concentration ◽  
Chitosan Derivatives ◽  
Cytotoxicity Activity ◽  
Gram Positive Bacteria ◽  
Anti Cancer ◽  
Ft Ir ◽  
Active Intermediates

Versatile hybrid organic polymers are prepared using two active intermediates such as cynuric chloride and chitosan derivatives. The prepared chalcones are characterized by using FT-IR, UV, and proton NMR, thermal analysis and Minimum inhibitory Concentration. Thermal stability of the synthesized hybrid polymer is found using TGA and the hybrid chitosan derivative chalcone is thermally stable up to 270 °C. The antimicrobial activity of the prepared chitosan containing chalcone moiety are find out using Minimum Inhibitory Concentration (MIC) method. The synthesized versatile chalcone shows excellent antimicrobial activity against gram-negative bacteria such as Pseudomonas aeruginosa; and Gram-positive bacteria Chalcone containing halogen moiety shows high activity (MIC 7.8 µg/mL) than the hydroxyl containing chalcone. Cytotoxicity activity of the synthesized composites shows high activity.

scholarly journals Synthesis and in vitro Antibacterial Activity of Quaternization 10-Methoxycanthin-6-one Derivatives

2019 ◽  
Author(s):  
Na Li ◽  
Jiang-Kun Dai ◽  
Dan Liu ◽  
Jin-Yi Wang ◽  
Jun-Ru Wang
Keyword(s):  
Antibacterial Activity ◽  
Natural Products ◽  
Minimum Inhibitory Concentration ◽  
Pathogenic Bacteria ◽  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Dilution Method ◽  
In Vitro Antibacterial Activity

Natural products are an important source of antibacterial agents. Canthin-6-one alkaloids have displayed potential antibacterial activity based on our previous work. In order to improve the activity, twenty-two new 3-N-benzylated 10-methoxy canthin-6-ones were designed and synthesized through quaternization reaction. The in vitro antibacterial activity against three bacteria was evaluated by double dilution method. Four compounds (6f, 6i, 6p and 6t) displayed 2-fold superiority (minimum inhibitory concentration (MIC) = 3.91 µg/mL) against agricultural pathogenic bacteria R. solanacearum and P. syringae than agrochemical propineb. Moreover, the structure–activity relationships (SARs) were also carefully summarized in order to guide the development of antibacterial canthin-6-one agents.

scholarly journals Determination of Minimum Inhibitory Concentration (MIC) and percentage Bacterial Growth Inhibition of essential oils against Gram Positive Bacterial pathogens

2019 ◽  
Vol 9 (3) ◽  
pp. 33-35
Author(s):  
S. Nagalakshmi ◽  
P. Saranraj ◽  
P. Sivasakthivelan
Keyword(s):  
Staphylococcus Aureus ◽  
Bacillus Subtilis ◽  
Minimum Inhibitory Concentration ◽  
Growth Inhibition ◽  
Essential Oils ◽  
Bacterial Growth ◽  
Inhibitory Concentration ◽  
Gram Positive ◽  
Bacterial Growth Inhibition

Essential oils and volatile constituents extracted from Aromatic plants are frequently used in folk medicine for prevention and treatment of different human diseases. The urge to develop alternative treatment strategies follows three different directions. In the present study, an attempt has been planned to determine the Minimum Inhibitory Concentration (MIC) and Percentage Growth Inhibition of Essential oils against two Gram positive bacterial pathogens, Staphylococcus aureus and Bacillus subtilis. The Essential oils selected for the present study was collected from Sidha Medicine Shop, Tirupattur, Vellore district, Tamil Nadu, India. The Broth dilution method was used for the determination of Minimum Inhibitory Concentration (MIC) of Essential oils. The Minimum Inhibitory Concentration (MIC) studies were conducted by using various concentrations of Essential oils viz., 25 µl/ml, 50 µl/ml, 75 µl/ml and 100 µ/ml. The Essential oils exhibits inhibitory activity against Gram positive bacteria in all the concentrations. Among the seven Essential oils tested, Mahualongif oil has showed maximum percentage bacterial growth inhibition when compared to other Essential oils. The inhibitory activity of Mahualongif oil was observed more in Staphylococcus aureus when compared to Bacillus subtilis. For Staphylococcus aureus, lowest inhibitory percentage was noticed in Pungam oil and for Bacillus subtilis lowest inhibitory percentage was noticed in Coconut oil. Keywords: Essential oils, Minimum inhibitory concentration (MIC), Percentage bacterial growth inhibition, Bacillus subtilis and Staphylococcus aureus.

scholarly journals Antibacterial Activity of Grepafloxacin

1998 ◽  
Vol 9 (suppl e) ◽  
pp. 4E-9E
Author(s):  
B Wiedemann ◽  
P Heisig
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Respiratory Tract Infections ◽  
Inhibitory Concentration ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Pharmacodynamic Profile ◽  
Resistant Mutants ◽  
Tract Infections ◽  
Relative Differences

Grepafloxin has an extremely broad spectrum of activity. Its activity against Gram-positive bacteria exceeds that of currently available quinolones. Grepafloxacin-resistant mutants seem to occur less frequently than ciprofloxacin - or ofloxacin-resistant mutants, and the increase in minimum inhibitory concentration (MIC) against the former mutants is less than that of the latter. This applies only to the relative differences (in dilution steps); the absolute values are similar. Grepafloxacin kills Gram-positive bacteria at concentrations little above the MIC. Its pharmacodynamic profile against pneumococci is promising, favouring use of this drug for respiratory tract infections.

scholarly journals Microwave assisted synthesis of novel 4h-chromene derivatives bearing phenoxypyrazole and their antimicrobial activity assess

2012 ◽  
Vol 77 (9) ◽  
pp. 1165-1174 ◽  
Author(s):  
Chetan Sangani ◽  
Nimesh Shah ◽  
Manish Patel ◽  
Ranjan Patel
Keyword(s):  
Bacillus Subtilis ◽  
Candida Albicans ◽  
Inhibitory Concentration ◽  
Salmonella Typhi ◽  
Microwave Assisted Synthesis ◽  
Gram Negative Bacteria ◽  
Clostridium Tetani ◽  
Gram Positive Bacteria ◽  
Concentration Method ◽  
Mic Minimum Inhibitory Concentration

A new series of 4H-chromene derivatives 4(a-p) bearing 5-phenoxypyrazole nucleus has been synthesized under microwave irradiation by reaction of 5-phenoxypyrazole-4-carbaldehyde 1(a-h), malononitrile 2 and compounds (Cyclohexanedione, Dimedon) 3(a-b) in presence of NaOH as basic catalyst. All the compounds were screened against three Gram positive bacteria (Streptococcus pneumoniae, Clostridium tetani, Bacillus subtilis), three Gram negative bacteria (Salmonella typhi, Vibrio cholerae, Escherichia coli) and two fungi (Aspergillus fumigatus, Candida albicans) using broth microdilution MIC (Minimum Inhibitory Concentration) method. Upon study of antimicrobial screening, it has been observed that, majority of the compounds were found to be active against Clostridium tetani and Bacillus subtilis as well as against Candida albicans as compared to standard drugs.

scholarly journals Antibacterial Activity of Murrayaquinone A and 6-Methoxy-3,7-dimethyl-2,3-dihydro-1H-carbazole-1,4(9H)-dione

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Biswanath Chakraborty ◽  
Suchandra Chakraborty ◽  
Chandan Saha
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Antibacterial Activities ◽  
Gram Positive ◽  
Gram Negative ◽  
Naturally Occurring

The antibacterial activity of Murrayaquinone A (10), a naturally occurring carbazoloquinone alkaloid, and 6-methoxy-3,7-dimethyl-2,3-dihydro-1H-carbazole-1,4(9H)-dione (11), a synthetic carbazoloquinone, both obtained during the development of the synthesis of Carbazomycin G, having unique quinone moiety, was studied against Gram-positive (Bacillus subtilisandStaphylococcus aureus) and Gram-negative (Escherichia coliandPseudomonassp.) bacteria. Compound10showed antibacterial activities against both ofEscherichia coliandStaphylococcus aureuswhereas compound11indicated the activity againstStaphylococcus aureusonly. Both compounds10and11exhibited minimum inhibitory concentration (MIC) of 50 μg mL−1againstStaphylococcus aureus.

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