Medicinal plants, vegetables and fruits are the sources of huge number of bioactive lead/scaffolds with therapeutic and nutraceutical importance. Bioautography is a means of target-directed isolation of active molecul...Medicinal plants, vegetables and fruits are the sources of huge number of bioactive lead/scaffolds with therapeutic and nutraceutical importance. Bioautography is a means of target-directed isolation of active molecules on chromatogram. Organic solvents employed in chromatographic separation process can be completely removed before biological detection because these solvents cause inactivation of enzymes and/or death of living organisms. They offer a rapid and easy identification of bioactive lead/scaffolds in complex matrices of plant extracts. Bioautography is a technique to isolate hit（s）/lead（s） by employing a suitable chromatographic process followed by a biological detection system. This review critically describes the methodologies to identify antimicrobial, antioxidant, enzyme inhibitor lead/scaffolds by employing bioautography. A significant number of examples have been incorporated to authenticate the methodologies.展开更多
Objective: To evaluate the biological activities of Combretum erythrophyllum(C. erythrophyllum) leaf extracts against infectious diseases' pathogenesis and their cytotoxicity potentials. Methods: Powdered leaf mat...Objective: To evaluate the biological activities of Combretum erythrophyllum(C. erythrophyllum) leaf extracts against infectious diseases' pathogenesis and their cytotoxicity potentials. Methods: Powdered leaf material(300 g) of C. erythrophyllum was extracted(1:10 w/v) using acetone to obtain the crude extract. Liquid-liquid fractionation was performed on the crude acetone extract(30 g) using solvents of different polarity. The bioautographic method was used to detect the inhibition of bacterial and fungal growth by active compounds present in the crude and fractions. The extracts were then tested on bacterial strains: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa; fungal strains: Candida albicans(C. albicans), Cryptococcus neoformans, and Aspergillus fumigatus, by microtitre dilution method for MIC determination. Results: The extracts MIC values ranged between 0.08–2.50 mg/m L against the tested pathogens. Water fraction had the highest activity against bacteria strains, while the fungal assay revealed crude acetone extract and ethyl acetate fraction to be active against C. albicans(1.25 mg/m L), dichloromethane extract against C. albicans and Aspergillus fumigatus(0.16 mg/m L). Extract fractions showed a good antioxidant activity via DPPH, ABTS and hydroxyl radical scavenging assays, in the order: ethyl acetate > water > acetone > dichloromethane > hexane. The toxicity level of crude extract and fractions evaluated in Vero monkey kidney cells ranged from 34–223 μg/m L, while doxorubicin(IC_(50) = 7.19 μg/m L) served as the positive control. Conclusions: It can be concluded that the extracts of C. erythrophyllum are safe for medicinal use in folk medicine for treating infectious and stress related diseases.展开更多
Antibiotic-resistant bacteria continue to be of major health concern world-wide. Thus, it is of great interest to study the biological properties and determine active compounds in natural products likely to be used as...Antibiotic-resistant bacteria continue to be of major health concern world-wide. Thus, it is of great interest to study the biological properties and determine active compounds in natural products likely to be used as new health remedies. Therefore, the main objective of this work is to test the antibacterial activity of royal jelly samples, defatted royal jelly samples and their ethyl ether extracts against bacteria capable of infecting cutaneous wounds in humans and animals, and to recognize major bioactive compounds by using bioassay directed identification. The microorganisms used in the study were Staphylococcus aureus (including Methicillin-resistant and sensitive strains), Staphylococcus epidermidis, Micrococcus luteus, Streptococcus uberis, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. The activity of royal jelly samples to inhibit bacterial growth was assessed by using well-difussion tests. Direct bioautography was used to identify bioactivity, and uv-visible spectroscopy and gas chromatography-mass spectrometry were used to identify bioactive compounds. Overall, royal jelly samples showed higher growth inhibition activity against Gram positive bacteria as compared to Gram negative bacteria. The growth of bacterial strains belonging to the Enterococcus and Streptococcus genders was less affected by the presence of royal jelly than bacterial strains of the Staphylococcus gender did. Compounds with antibacterial activity were found in the ethyl ether extract of royal jelly samples. 10-hydroxy-2-decenoic acid was the major component identified in the purified fraction obtained by bioassay guided fractionation of the ethyl ether extract. In conclusion, bioactivity of royal jelly samples is mainly due to their 10-hydroxy-2-decenoic acid content.展开更多
Fruits and vegetables are an essential part of a healthy diet, providing humans with vitamins, phytonutrients, and minerals. They are significantly vulnerable, however, to post-harvest diseases caused by numerous fung...Fruits and vegetables are an essential part of a healthy diet, providing humans with vitamins, phytonutrients, and minerals. They are significantly vulnerable, however, to post-harvest diseases caused by numerous fungal and bacterial pathogens. These pathogens can cause significant quantitative and qualitative losses from harvest to consumption during the handling and storage processes. Chemical fungicides are commonly used but are likely to leave residues on the produce, rendering short shelf-life produce, such as berries, unsuitable for human consumption. Identifying eco-friendly methods to control post-harvest disease is, therefore, of utmost importance. The presence of antifungal constituents in the roots of Poncirus trifoliata extracts was detected by thin layer chromatography-based bioautography. The active constituents were isolated and identified by bioautography assay-guided fractionation using flash chromatography followed by spectroscopic techniques. In this study, xanthoxyletin, demethylsuberosin, dentatin, nordentatin, ponfolin, and clausarin were isolated from the root extracts. The antifungal activity of these compounds was moderate to weak compared to the commercial fungicide captan. This study reports the isolation and identification of natural compounds from Poncirus trifoliata that exhibited antifungal activity against Colletotrichum fragariae and Botrytis cinerea, two major post-harvest pathogens.展开更多
Background:This research values the antioxidant activity and its responsible molecules in six essential oils from medicinal plants in the Ecuadorian Andes.Methods:The chemical composition of essential oils was determi...Background:This research values the antioxidant activity and its responsible molecules in six essential oils from medicinal plants in the Ecuadorian Andes.Methods:The chemical composition of essential oils was determined using gas chromatography coupled mass spectrometry.For evaluated the antioxidant activity of essential oils was use tree spectrophotometric methods:diphenyl-1-picrylhydrazyl(DPPH),2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)(ABTS)andβ-Carotene bleaching test.The essential oils with good activity were determined the responsible molecules using the Bioautographic HP-TLC-DPPH method.Results:The scavenging capacity of the radicals was assessed with DPPH and ABTS methods,the best results were found in the oils of M.mollis IC_(50) DPPH 2.80 mg/ml and IC_(50) ABTS 0.205 mg/mL and in A.glutinosa IC_(50) DPPH 12.972 mg/mL and IC_(50) ABTS 0.321 mg/mL,the results were compared with a pattern of natural reference in this case,the essential oil of T.vulgaris IC_(50) DPPH 0.474 mg/mL and IC_(50) ABTS 0.272 mg/mL.The evaluation of the antioxidant activity was determined by theβ-carotene bleaching test,the most notable activity results were from M.mollis IC_(50)0.119 mg/mL,A.glutinosa IC_(50)0.062 mg/mL and B.latifolia IC_(50)0,064 mg/mL.DPPH bioautography revealed the active molecules antioxidants in oils for M.mollis were thymol acetate(7.73%)and carvacrol acetate(24.52%),for A.glutinosa wasγ-muurolene(2.68%),and for B.latifolia Z-caryophyllene(2.99%),aristolochene(0.11%)and cis-cadin-4-en-7-ol(4.11%).Conclusion:The results of antioxidant activity shown in descending order that the essential oils of:M.mollis,A.glutinosa and B.latifolia,are those with the highest activity using the DPPH and ABTS methods.Theβ-Carotene bleaching test method confirms the 3 oils as the most active in the following order:A.glutinosa,B.latifolia and M.mollis.An antioxidant bioautographic study identified the molecules responsible for the activity in three essential oils with good activity.展开更多
文摘Medicinal plants, vegetables and fruits are the sources of huge number of bioactive lead/scaffolds with therapeutic and nutraceutical importance. Bioautography is a means of target-directed isolation of active molecules on chromatogram. Organic solvents employed in chromatographic separation process can be completely removed before biological detection because these solvents cause inactivation of enzymes and/or death of living organisms. They offer a rapid and easy identification of bioactive lead/scaffolds in complex matrices of plant extracts. Bioautography is a technique to isolate hit（s）/lead（s） by employing a suitable chromatographic process followed by a biological detection system. This review critically describes the methodologies to identify antimicrobial, antioxidant, enzyme inhibitor lead/scaffolds by employing bioautography. A significant number of examples have been incorporated to authenticate the methodologies.
基金the financial support of Directorate of Research,Vaal University of Technology and Prof. JN Eloff (University of Pretoria) for the plant sample
文摘Objective: To evaluate the biological activities of Combretum erythrophyllum(C. erythrophyllum) leaf extracts against infectious diseases' pathogenesis and their cytotoxicity potentials. Methods: Powdered leaf material(300 g) of C. erythrophyllum was extracted(1:10 w/v) using acetone to obtain the crude extract. Liquid-liquid fractionation was performed on the crude acetone extract(30 g) using solvents of different polarity. The bioautographic method was used to detect the inhibition of bacterial and fungal growth by active compounds present in the crude and fractions. The extracts were then tested on bacterial strains: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa; fungal strains: Candida albicans(C. albicans), Cryptococcus neoformans, and Aspergillus fumigatus, by microtitre dilution method for MIC determination. Results: The extracts MIC values ranged between 0.08–2.50 mg/m L against the tested pathogens. Water fraction had the highest activity against bacteria strains, while the fungal assay revealed crude acetone extract and ethyl acetate fraction to be active against C. albicans(1.25 mg/m L), dichloromethane extract against C. albicans and Aspergillus fumigatus(0.16 mg/m L). Extract fractions showed a good antioxidant activity via DPPH, ABTS and hydroxyl radical scavenging assays, in the order: ethyl acetate > water > acetone > dichloromethane > hexane. The toxicity level of crude extract and fractions evaluated in Vero monkey kidney cells ranged from 34–223 μg/m L, while doxorubicin(IC_(50) = 7.19 μg/m L) served as the positive control. Conclusions: It can be concluded that the extracts of C. erythrophyllum are safe for medicinal use in folk medicine for treating infectious and stress related diseases.
文摘Antibiotic-resistant bacteria continue to be of major health concern world-wide. Thus, it is of great interest to study the biological properties and determine active compounds in natural products likely to be used as new health remedies. Therefore, the main objective of this work is to test the antibacterial activity of royal jelly samples, defatted royal jelly samples and their ethyl ether extracts against bacteria capable of infecting cutaneous wounds in humans and animals, and to recognize major bioactive compounds by using bioassay directed identification. The microorganisms used in the study were Staphylococcus aureus (including Methicillin-resistant and sensitive strains), Staphylococcus epidermidis, Micrococcus luteus, Streptococcus uberis, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. The activity of royal jelly samples to inhibit bacterial growth was assessed by using well-difussion tests. Direct bioautography was used to identify bioactivity, and uv-visible spectroscopy and gas chromatography-mass spectrometry were used to identify bioactive compounds. Overall, royal jelly samples showed higher growth inhibition activity against Gram positive bacteria as compared to Gram negative bacteria. The growth of bacterial strains belonging to the Enterococcus and Streptococcus genders was less affected by the presence of royal jelly than bacterial strains of the Staphylococcus gender did. Compounds with antibacterial activity were found in the ethyl ether extract of royal jelly samples. 10-hydroxy-2-decenoic acid was the major component identified in the purified fraction obtained by bioassay guided fractionation of the ethyl ether extract. In conclusion, bioactivity of royal jelly samples is mainly due to their 10-hydroxy-2-decenoic acid content.
文摘Fruits and vegetables are an essential part of a healthy diet, providing humans with vitamins, phytonutrients, and minerals. They are significantly vulnerable, however, to post-harvest diseases caused by numerous fungal and bacterial pathogens. These pathogens can cause significant quantitative and qualitative losses from harvest to consumption during the handling and storage processes. Chemical fungicides are commonly used but are likely to leave residues on the produce, rendering short shelf-life produce, such as berries, unsuitable for human consumption. Identifying eco-friendly methods to control post-harvest disease is, therefore, of utmost importance. The presence of antifungal constituents in the roots of Poncirus trifoliata extracts was detected by thin layer chromatography-based bioautography. The active constituents were isolated and identified by bioautography assay-guided fractionation using flash chromatography followed by spectroscopic techniques. In this study, xanthoxyletin, demethylsuberosin, dentatin, nordentatin, ponfolin, and clausarin were isolated from the root extracts. The antifungal activity of these compounds was moderate to weak compared to the commercial fungicide captan. This study reports the isolation and identification of natural compounds from Poncirus trifoliata that exhibited antifungal activity against Colletotrichum fragariae and Botrytis cinerea, two major post-harvest pathogens.
文摘Background:This research values the antioxidant activity and its responsible molecules in six essential oils from medicinal plants in the Ecuadorian Andes.Methods:The chemical composition of essential oils was determined using gas chromatography coupled mass spectrometry.For evaluated the antioxidant activity of essential oils was use tree spectrophotometric methods:diphenyl-1-picrylhydrazyl(DPPH),2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)(ABTS)andβ-Carotene bleaching test.The essential oils with good activity were determined the responsible molecules using the Bioautographic HP-TLC-DPPH method.Results:The scavenging capacity of the radicals was assessed with DPPH and ABTS methods,the best results were found in the oils of M.mollis IC_(50) DPPH 2.80 mg/ml and IC_(50) ABTS 0.205 mg/mL and in A.glutinosa IC_(50) DPPH 12.972 mg/mL and IC_(50) ABTS 0.321 mg/mL,the results were compared with a pattern of natural reference in this case,the essential oil of T.vulgaris IC_(50) DPPH 0.474 mg/mL and IC_(50) ABTS 0.272 mg/mL.The evaluation of the antioxidant activity was determined by theβ-carotene bleaching test,the most notable activity results were from M.mollis IC_(50)0.119 mg/mL,A.glutinosa IC_(50)0.062 mg/mL and B.latifolia IC_(50)0,064 mg/mL.DPPH bioautography revealed the active molecules antioxidants in oils for M.mollis were thymol acetate(7.73%)and carvacrol acetate(24.52%),for A.glutinosa wasγ-muurolene(2.68%),and for B.latifolia Z-caryophyllene(2.99%),aristolochene(0.11%)and cis-cadin-4-en-7-ol(4.11%).Conclusion:The results of antioxidant activity shown in descending order that the essential oils of:M.mollis,A.glutinosa and B.latifolia,are those with the highest activity using the DPPH and ABTS methods.Theβ-Carotene bleaching test method confirms the 3 oils as the most active in the following order:A.glutinosa,B.latifolia and M.mollis.An antioxidant bioautographic study identified the molecules responsible for the activity in three essential oils with good activity.
