scholarly journals Anti-fungal activities of constituents from Uvaria scheffleri and Artabotrys brachypetalus

2006 ◽  
Vol 51 (1) ◽  
pp. 79-86 ◽  
Author(s):  
A.C. Odebode ◽  
S.A. Jonker ◽  
C.C. Joseph ◽  
S.W. Wachira

The anti-fungal activity of schefflone, a mixture of dimmer, 3,5 dimethoxy carvacrol and annonaceous acetogenin, extracted from stem-bark and root of Uvaria scheffleri and Artabotrys bruchypetalus against Fusarium solani, Botryodiplodia theobromae, Asperillus niger and Aspergillus flavus was determined. An in-vitro bioassay showed that the minimum inhibitory effect of the compounds to the fungal pathogens occurred at 200 ppm in both radial growth and mycelia dry weight measurements. Acetogenin from A brachypetalus had a very strong anti-fungal effect on all the test fungi. The effects of the compounds were more pronounced on F solani than on the other. The bioassay methods also play a significant role in the sensitivity of the samples on the pathogens. .

Author(s):  
Patrick Ishoro Akwaji ◽  
Ekeng Ita Okon ◽  
Etim Johnson Umana ◽  
Aniedi Abasi Akpan Markson

The phytochemical and antifungal efficacy of the ethanolic and methanolic stem bark and leaf extracts of Parkiabiglobosa on the fungal pathogens isolated from infected green bean seeds obtained from the field in Akpabuyo, Cross River State, Nigeria were investigated in vitro. The pathogens were Botryodiplodiatheobromae and Aspergillusniger. Various concentrations of the extracts ranging from 10g/100ml, 20g/100ml, 30g/100ml, 40g/100ml and 50g/100ml were separately added to PDA media. Results of the in vitro antifungal assay shows that at 40g/100ml and 50g/100ml concentrations, ethanolic stem bark and leaf extracts of P. biglobosa completely inhibited the radial growth of B. theobromae and A. niger after seven days observation period while those of methanolic extracts completely inhibited the redial growth of the fungal pathogens at 50g/100ml concentration. Results, however, shows that the extracts had a significant effect (P<0.05) on the radial growth of the fungal pathogens at all the different concentrations tested as compared with the control. Pathogen growth inhibition was most effective at 30g/100ml, 40g/100ml and 50g/100ml concentrations. The inhibitory action of the extracts increased/decreased with a corresponding increase/decrease in the concentration of the plant extracts. Ethanolic stem bark and leaf extracts of P. biglobosa was found to be more effective in inhibiting the redial growth of the fungal pathogens than those of methanolic extracts, also ethanolic and methanolic stem bark extracts were observed to be more effective in the inhibition of the radial growth of the fungal pathogens than leaf extracts. Phytochemical screening of the extracts revealed the presence of cardiac glycosides, reducing sugars, flavonoids, saponnins and tannins with traces of alkaloids in stem bark extracts while flavonoids, alkaloids, cardiac glycosides, saponnins, tannins and terpenoids were present in leaf extracts.


2020 ◽  
pp. 1942-1948
Author(s):  
Nancy Karimi Njeru ◽  
Charles Aura Odhiambo Midega ◽  
James Wanjohi Muthomi ◽  
John Maina Wagacha ◽  
Zeyaur Rahman Khan

Maize grown under push-pull cropping system has been reported to contain lower concentrations of fumonisin and aflatoxin than maize monocrop. This study determined the inhibitory effect of desmodium root extracts on spore germination and radial growth of toxigenic Aspergillus flavus and Fusarium verticillioides. Aspergillus flavus and F. verticillioides were isolated from maize and soil and tested for ability to produce aflatoxin and fumonisin by inoculation on mycotoxin-free maize. Aflatoxin and fuminisin were detected and quantified by direct competitive ELISA. Desmodium roots were dried, ground to fine powder and extracted with methanol and dichloromethane and evaluated for anti-fungal activity by inhibition of spores of A. flavus and F. verticillioides potato dextrose agar (PDA) medium. Isolates of F. verticillioides produced up to 599,741 µg/kg fumonisin while isolates of A. flavus produced up to 199,184 µg/kg aflatoxin. Desmodium root extracts reduced germination of A. flavus spores and F. verticillioides by 9.6% and 43.8%, respectively and reduced their respective colony radial growth by 15% and 57%. The results suggested that desmodium roots contain chemical compounds that inhibit growth of A. flavus and F. verticillioides. This may explain the reduction in infection of maize with mycotoxin-producing fungi before harvest in push-pull cropping systems by reducing the pathogen inoculum in the soils. Determination of the active compounds in the root exudates is recommended


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Mostafa M. El-Sheekh ◽  
Ayman Y. Ahmed ◽  
Amira S. Soliman ◽  
Siham E. Abdel-Ghafour ◽  
Hassan M. Sobhy

Abstract Background In this study, the potential of extracts and powders of green seaweeds, Ulva fasciata, and Enteromorpha flexuosa was evaluated as biocontrol against the pathogenic soil-borne fungi, Macrophomina phaseolina and Fusarium solani, infecting cucumber plants in Egypt. The antifungal activity of the algal extracts was evaluated in vitro against the pathogens mycelial fungal growth using five organic solvents. Results Obtained results indicated that mycelial growth inhibition was noticed with F. solani in all algal extracts tested. In M. phaseolina, all algal extracts did not inhibit the fungal growth but affected microsclerotia formation (the main source of the second infection). In the case of F. solani, the highest reduction (68.6%) was noticed, while the chloroform extract of U. fasciata inhibited the radial growth of F. solani to 2.5 cm when E. flexuosa inhibited the radial growth to 4.3 cm as compared with the control (8.0 cm). The gas chromatography-mass spectrometry and the infrared spectroscopy analyses revealed that iron-monocarbonyl, cyclononasiloxane, and their functional groups, including amine, ether, etc., might play a core role in the anti-fungal activity of the seaweed extracts used. Conclusion This work concluded that the macroalgae species with many unique antifungal properties components had an inhibitory effect against soil-borne cucumber diseases. The antimicrobial activity might be explored in the future in numerous diverse applications in agriculture and plant disease control, revealing their actions to control some plant fungal pathogens.


Author(s):  
Iván De-la-Cruz-Chacón ◽  
Nora Yazmin López-Fernández ◽  
Christian Anabí Riley-Saldaña ◽  
Marisol Castro Moreno ◽  
Alma Rosa González-Esquinca

Background and Aims: The phytochemistry study of Annonaceae has intensified in the last decades due to the discovery of secondary metabolites with antimicrobial activities. The inhibitory activities of extracts and compounds from these species for phytopathogens are less known. The antifungal activity of Sapranthus microcarpus was determined in vitro against six fungal pathogens of important crops.Methods: Hexane, methanol, and alkaloid extracts of the leaves and root and stem bark of S. microcarpus were evaluated to determine whether they could inhibit the mycelial growth of the phytopathogens. The combined activity of the most active extracts for each phytopathogen was also determined. The alkaloid liriodenine was isolated and identified as an antifungal principle.Key results: All extracts inhibited the growth of the six phytopathogens to some extent. The root bark alkaloid extract showed the highest activity. Fusarium oxysporum f. sp. lycopersici and Curvularia lunata were the most sensitive phytopathogens. Liriodenine was active against all the plant pathogens (minimum inhibitory concentrations of 125-500 nmol ml-1).Conclusions: Sapranthus microcarpus is a native natural resource with great phytochemical potential.


2002 ◽  
Vol 51 (1-2) ◽  
pp. 107-114 ◽  
Author(s):  
I. Jevcsák ◽  
Bálint Oldal ◽  
L. Ködöböcz ◽  

The antagonistic effect of thirteen Pseudomonas aeruginosa and thirteen strains of other Pseudomonas species was studied on the soil-borne phytopathogenic Rhizoctonia solani and Fusarium solani fungi.  The inhibition of pathogen colony growth was tested with two different in vitro techniques using the same type of culture media. In case of the spread slant technique the antagonists induced a significantly stronger inhibition on the growth of pathogens than in case of spot transfer. Among the 26 investigated Pseudomonas strains, P. aeruginosa strains were generally more effective against the fungal pathogens. Rhizoctonia solani proved to be affected to a greater extent by the bacterial strains studied than the Fusarium solani representative. The possibility of in vitro strain selection of biocontrol microbes is being further discussed .


Author(s):  
Abdulhafiz Damilola Oso ◽  
Idris Bello ◽  
Yusuf Sa’idu ◽  
Onu Andrew

The aim of the current study is to evaluate the inhibition of α-glucosidase activity by stem bark extract of Albizia chevalieri. The activity of alpha glucosidase was assayed in vitro using 50 mM acetate buffer pH 6.0 (prepared from acetic acid and sodium acetate) and various concentration of maltose (0.5 mM to 10 mM). Five test tubes, labeled TA – TE, each containing 1.5 ml of acetate buffer, 0.5 ml of alpha glucosidase and 0.5 ml of a known concentration of plant extract and control tubes (CA – CE) were assessed for Alpha glucosidase activity. The results showed that hexane, ethyl acetate and methanol extracts inhibited α-glucosidase activity. The results further indicated that the extracts act by competitive inhibition with inhibition constant of 232 mg/ml, 157 mg/ml and 67 mg/ml for hexane, ethyl acetate and methanol extracts, respectively. The value for the inhibition constants shows that there is a strong binding of the enzyme to the inhibitor as the polarity of solvent increases. The inhibitory activity of Albizia chevalieri may be due one or more of the phytochemicals present in the extracts.


2017 ◽  
Vol 5 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Srijana Bastakoti ◽  
Shiva Belbase ◽  
Shrinkhala Manandhar ◽  
Charu Arjyal

Soil borne pathogenic fungi are of major concern in agriculture which significantly decreases the plant yield. Chemically controlled plant imposes environmental threats potentially dangerous to humans as well as other animals. Thus, application of biological methods in plant disease control is more effective alternative technique. This study was carried out to isolate Trichoderma species from soil sample and to assess its in vitro biocontrol efficacy against fungal pathogens viz. Sclerotium rolfsii, Sclerotionia sclerotiorum, Fusarium solani and Rhizoctonia solani. Biocontrol efficacy testing of isolates against different fungal pathogens was performed by dual culture technique.In this study, 5 different Trichoderma species were isolated from 26 various soil samples and were tested against four fungal soil-borne pathogens. Inhibition percentage of radial growth of Sclerotium rolfsii by three of the Trichoderma isolates was found to be 100%; about 62% and 68% of maximum inhibition was observed against Rhizoctonia solani and Fusarium solani respectively whereas Sclerotionia sclerotiorum was inhibited maximum up to 23%. This in vitro study revealed that although Trichoderma species plays an important role in controlling all type of soil borne fungal plant pathogens, however, isolates as biocontrol agent against Sclerotium rolfsii was found to be more efficient in comparison to other pathogens.Nepal Journal of Biotechnology. Dec. 2017 Vol. 5, No. 1: 39-49


1998 ◽  
Vol 11 (3) ◽  
pp. 228-236 ◽  
Author(s):  
Rachel E. Melton ◽  
Lynda M. Flegg ◽  
James K. M. Brown ◽  
Richard P. Oliver ◽  
Michael J. Daniels ◽  
...  

The anti-fungal, steroidal, glycoalkaloid saponin, α-tomatine, is present in uninfected tomato plants in substantial concentrations, and may contribute to the protection of tomato plants against attack by phytopathogenic fungi. In general, successful fungal pathogens of tomato are more resistant to α-tomatine in vitro than fungi that do not infect this plant. For a number of tomato pathogens, this resistance has been associated with the ability to detoxify α-tomatine through the action of enzymes known as tomatinases. In contrast, the biotrophic tomato pathogen Cladosporium fulvum is sensitive to α-tomatine and is unable to detoxify this saponin. This paper describes the effects of heterologous expression of the cDNA encoding tomatinase from the necrotroph Septoria lycopersici in two different physiological races of C. fulvum. Tomatinase-producing C. fulvum transformants showed increased sporulation on cotyledons of susceptible tomato lines. They also caused more extensive infection of seedlings of resistant tomato lines. Thus, α-tomatine may contribute to the ability of tomato to restrict the growth of C. fulvum in both compatible and incompatible interactions.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1053
Author(s):  
Ștefania Adelina Milea ◽  
Mihaela Aida Vasile ◽  
Oana Crăciunescu ◽  
Ana-Maria Prelipcean ◽  
Gabriela Elena Bahrim ◽  
...  

In this study, flavonoids extracted from yellow onion skins and Lactobacillus casei were encapsulated in a combination of whey protein isolate, inulin and maltodextrin with an encapsulation efficiency of 84.82 ± 0.72% for flavonoids and 72.49 ± 0.11% for lactic acid bacteria. The obtained powder showed a flavonoid content of 89.49 ± 4.12 mg quercetin equivalents/g dry weight (DW) and an antioxidant activity of 39.27 ± 0.45 mM Trolox/g DW. The powder presented a significant antidiabetic and anti-inflammatory potential, with an inhibitory effect on α-amylase, lipase and lipoxygenase of 76.40 ± 2.30%, 82.58 ± 3.36% and 49.01 ± 0.62%, respectively. The results obtained for in vitro digestion showed that the coating materials have a protective effect on the flavonoids release. Cytotoxicity results indicated that the powder was cytocompatible up to a concentration of 500 μg/mL. The functional potential of the powder was tested by adding in a selected food matrix, highlighting a good stability of the phytochemicals, whereas an increase with 1 log cell forming unit (CFU)/g DW was observed after 21 days of storage. The obtained results are promising in the valorization of natural antioxidants in combination with lactic acid bacteria in order to develop multifunctional ingredients with value-added for food and pharmaceutics applications.


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