scholarly journals The effect of lichen secondary metabolites on Aspergillus fungi

2021 ◽  
Vol 204 (1) ◽  
Author(s):  
Łukasz Furmanek ◽  
Paweł Czarnota ◽  
Mark R. D. Seaward

AbstractA systematic review of literature data on the antifungal potential of extracted lichen compounds and individual secondary metabolites against mold species of the genus Aspergillus is provided. Crude extracts from 49 epiphytic, 16 epigeic and 22 epilithic species of lichens and 44 secondary metabolites against 10 species, Aspergillus candidus, A. flavus, A. fumigatus, A. nidulans, A. niger, A. ochraceus, A. parasiticus, A. restrictus, A. stellatus and A. ustus, were analysed. Several measuring techniques were employed for such analyses. Lichen substances were extracted with alcoholic and other organic solvents mainly using the Soxhlet apparatus. Among the three most-studied mold species, the results showed that the crude extracts from the thalli of the lichens Cladonia foliacea, Hypotrachyna cirrhata, Leucodermia leucomelos, Platismatia glauca and Pseudevernia furfuracea against Aspergillus flavus, from C. foliacea, Nephroma arcticum and Parmelia sulcata against A. fumigatus and from Evernia prunastri, Hypogymnia physodes, Umbilicaria cylindrica and Variospora dolomiticola against A. niger have the greatest antifungal potential. The lichen secondary metabolites showed a higher inhibitory potential, e.g. protolichesterinic acid against A. flavus, lecanoric acid against A. fumigatus and orsellinic acid against A. niger; the other seven species of Aspergillus have been poorly studied and require further investigation. A comparison of the inhibitory potential of the tested mixtures of lichen substances and their secondary metabolites shows that they can compete with commonly used antifungal substances, such as ketoconazole and clotrimazole against A. flavus, A. nidulans, A. niger and A. parasiticus and fluconazole in the case of A. fumigatus.

2021 ◽  
Vol 12 (3) ◽  
pp. 1793-1797
Author(s):  
Priyanka Sirari ◽  
Jigisha Anand ◽  
Devvret ◽  
Ashish Thapliyal ◽  
Nishant Rai

Green tea is credited as one of the world’s healthiest drinks with enriched antioxidants. It is known for its multi-beneficial health benefits against diabetes, blood pressure, hypertension, gastro-intestinal upset and is bestowed with significant antimicrobial potential. There are previous scientific evidence highlighting the antifungal potential of green tea and has identified it as a potential inhibitor of non-albicans Candida species. Lansterol 14-α demethylase (Erg 11) or CYP51 protein belongs to the cytochrome P450 monooxygenase (CYP) superfamily. Erg 11 is involved in ergosterol biosynthesis and has a significant role in azole drug resistance in Candida glabrata. The present study attempted to identify the inhibitory potential of green tea phytocompounds against inhibition of Erg 11 in Candida glabrata using bioinformatics tool viz., autodock vina software. Out of 15 green tea phytocompounds investigated, the study identified, Rutin (-10.5 kcal) Kaempferitrin (-9.4kcal), Epigallocatechin gallate (-10kcal), Epicatechin gallate (-8.7kcal), and Coumaroylquinic acid (-8.6kcal) acid as the potent phytocompounds which showed significant molecular interaction with Erg 11 in Candida glabrata. In attribution to the constant emergence of azole-resistant isolates, this preliminary analysis therefore, indicated the potential of green tea phytocompounds against inhibition of non-albicans Candida specific candidiasis. However, further, in vitro antimicrobial efficacy of these phytocompounds, the dose regime, drug likeliness, and cytotoxic analysis are required to be investigated and validated.


Author(s):  
R. S. Naphtali ◽  
J. S. Ngwamah

This study was aimed to investigate the insecticidal activities of some selected ethnobotanicals against culicine mosquitoes. Various part of plant material collected were extracted using Soxhlet apparatus Methanol and Petroleum ether were used as solvents. Quantitative phytochemical Analysis for the crude extracts was carried out for the presence of azadrachtin, terpenoids, alkaloids, tannins, saponins, glycoside, steroids phenol and flavonoids. The larvicidal potentials of the various crude extracts were then tested against culicine mosquitoes. More yields of phytochemical constituents (80.78 mg) were found in total of 900 g used for methanol extracts as compared to 57.64 mg found in 900 g used in petroleum ether extracts. All the extracts of methanol and petroleum ether of the different plant used showed larvicidal potentials against culicine 3rd instar larvae. The LC50 of the methanol extracts (37.32, 38.52, 42.05, 45.91, 68.78, 126.56, and 141.73 ppm) of E. globulus, O. kilimanscharicum, H. suaveolens, Neem seeds, neem stem leave and orange peels respectively, are far better than their counterparts of petroleum ether extracts with LC50 (100.25, 115.53, 145.88, 68.44, 114.55, 46.79, and 175.07 ppm). The larvicidal effect of individual isolates of alkaloids, tannin, saponins, azadirachtin, phenol and steroids demonstrated larvicidal potentials against 3rd instar larvae of culicine, where, terpenoids, flavonoids and glycoside showed no larvicidal potentials against culicine larvae. The larvicidal potential of each plant depend on the number of active ingredients and quantity available in each extract. In conclusion, the present plant extracts have potentials for development of new and safe control products for culicine mosquitoes.


2008 ◽  
Vol 56 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Diana Negrão Cavalcanti ◽  
Marcelo Augusto Vasconcelos Gomes ◽  
Angelo Cunha Pinto ◽  
Claudia Moraes de Rezende ◽  
Renato Crespo Pereira ◽  
...  

Crude extracts from specimens of the brown seaweed Dictyota menstrualis, known to produce diterpenes as their major secondary metabolites, were analyzed according to storage procedures before extraction, and the solvent types used to obtain the crude extracts. The specimens of D. menstrualis were submitted to three types of storage procedures, such as wet, dry, and frozen and were extracted with a mixture of dichloromethane:methanol (2:1) and acetone. Qualitative differences were not observed by GC/MS analyses of all crude extracts containing mainly the diterpenes pachydictyol A (I), 6-hydroxy-dichotoma-3,14-diene-1,17-dial (II), 6-hydroxy-2,7-cycloxenia-3,14-diene-1,17-dial (III), and 6-acetoxy-dichotoma-3,14-diene-1,17-dial (IV). The most efficient and selective extraction of the compounds with intermediate polarity produced by D. menstrualis was obtained using acetone, but with less mass production. In general, the storage procedures produced very similar results, but the frozen samples furnished low amount of total diterpenes. According to these results on chemical analysis of crude extracts of seaweeds, the choice of solvent to extraction should be considered as important aspect to better screening bioactive compounds.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Sephokoane Cindy Makuwa ◽  
Mahloro Hope Serepa-Dlamini

Endophytic bacteria isolated from medicinal plants are recognized valuable sources of novel bioactive compounds with various activities such as antimicrobial, anticancer, and antiviral. In this study, eleven bacterial endophytes were isolated from surface sterilized roots and leave tissues, of medicinal plant Dicoma anomala. The bacterial endophytes were identified by sequencing the 16S rRNA gene, and belong to five genera viz Bacillus, Staphylococcus, Stenotrophomonas, Enterobacter, and Pantoea. The dominant genera were Bacillus with five strains, Staphylococcus with two strains, and Stenotrophomonas with two strains. The crude extracts of seven selected bacterial endophytes indicated antimicrobial activity against five pathogenic strains Escherichia coli (ATCC 25922), Bacillus cereus (ATCC 10876), Staphylococcus aureus (NCTC 6571), Pseudomonas aeruginosa (ATCC 27853), and Klebsiella oxytoca (ATCC 13182), with significant inhibition concentration ranging from 0.312 mg/ml to 0.625 mg/ml. Finally, based on the data analysis of the crude extracts of the endophytes, we identified bioactive secondary metabolites with reported biological activities such as antimicrobial, anti-inflammatory, and antioxidant properties with biotechnological applications in medicine, agriculture, and other industries. This study reported for the first time bacterial endophytes associated with D. anomala, with antimicrobial activity against bacterial pathogens.


2021 ◽  
Vol 6 (2) ◽  
pp. 1-10
Author(s):  
Elkhateeb WA

Lichens exist in every continent and have a history of being used as food, medicine, a source of dyes and animal feed. Lichens are now being used as natural indicators of climate change and for air quality monitoring worldwide. Lichens play an important role in many ecosystems and exist as a symbiotic association between fungi and algae or cyanobacteria. This symbiosis results in the production of unique secondary metabolites known as lichen substances, which arise within the thalli and are typically in crystal form on the surface of the fungal hyphae. Recently, lichens and their secondary metabolites have been receiving increased attention due to their nutritional value and pharmaceutical potential. This review aims to highlight on the importance and variety of common lichen substances (secondary metabolites). Finally, the commercialization of lichens is growing but, in the future, metabolic and biotechnological approaches can be used as an alternative product to overcome the limited availability of biologically active, commercially valuable and medicinally important secondary metabolite components.


2020 ◽  
Vol 6 (3) ◽  
pp. 258-264
Author(s):  
OL Okunye ◽  
PA Idowu ◽  
TT Kolade

Background: Nauclea latifolia Smith (Rubiaceae) is a valuable medicinal plant used in folkloric medicine in the treatment of Typhoid fever. The public health significance of Salmonella typhi, the aetiologic agent in typhoid fever lies in the increasing resistance to antimicrobial agents. Objectives: To determine the antimicrobial potentials of the crude extracts of the leaves of Nauclea latifolia on clinical isolates of Salmonella typhi compared with some conventional antibiotics. Methods: Antibiogram was carried out on 25 biochemically confirmed clinical isolates of Salmonella typhi using disc diffusion method of Kirby Bauer. Nauclea latifolia leaves extracted with ethyl acetate and methanol in a Soxhlet apparatus were screened for secondary metabolites. The minimum inhibitory concentrations (MICs) of the extracts were determined by agar dilution method on the isolates. Results: The antibiogram of Samonella typhi showed the following resistance patterns: Augmentin® (24.0%), amoxicillin (44.0%), chloramphenicol (32.0%), gentamicin (20.0%), cloxacillin (96.0%), ciprofloxacin (8.0%), erythromycin (60.0%), tetracycline (32.0%) and cotrimoxazole (60.0%). The extracts showed good antibacterial activity on the clinical isolates including those resistant to antibiotics. The MIC of methanol extract ranged from1.56mg/ml to 6.25mg/ml and 3.13mg/ml to 25.0 mg/ml for ethyl acetate extract with exception of isolates 11, 12, 19 and 20 with high MIC values as 50mg/ml.  The methanol and ethyl acetate extracts gave a yield of 11.7% and 3.5% respectively. Bioactive secondary metabolites were detected from the extracts. Conclusion: The crude extracts of the leaves of Nauclea latifolia contained antimicrobial agents that were active on Salmonella typhi which could be used alone and in supportive with conventional antibiotics for therapeutic management of typhoid fever.


2019 ◽  
Vol 14 (7) ◽  
pp. 1934578X1985912 ◽  
Author(s):  
Claudio C. Cirne-Santos ◽  
Caroline de S. Barros ◽  
Max W. L. Gomes ◽  
Rafaela Gomes ◽  
Diana N. Cavalcanti ◽  
...  

Natural products isolated from seaweeds have shown great antiviral potential against numerous viruses such as human type 1 herpes, human immunodeficiency virus, and dengue. Diterpenes produced by the brown seaweeds Dictyota and Canistrocarpus, in particular, have shown antiviral or virucidal activity. Recently, the Zika virus (ZIKV) has become a major public health concern due to its widespread dissemination throughout the Americas. Since no vaccines are available, and no drugs have effectively treated recent cases of infection, our group evaluated products from Dictyota menstrualis for their antiviral potential, alone and in combination with Ribavirin. We first evaluated the compounds’ cytotoxicity at high concentrations, and then evaluated the inhibition of ZIKV replication by crude extracts and acetylated crude extracts and their fractions at 20 μg/mL. The F-6 and FAc-2 fractions, rich in cyclic diterpenes with aldehyde groupings, inhibited ZIKV replication by >74%, with inhibition behaving in a dose-dependent manner and the 50% effective concentration (EC50) values of 2.80 (F-6) and 0.81 (FAc-2) μg/mL. Regarding the mechanism of action, FAc-2 had strong virucidal potential, and F-6 inhibited viral adsorption. Associating FAc-2 with Ribavirin at suboptimal dosages produced a strong synergistic effect that completely inhibited viral replication. Our results indicate that these natural products have excellent inhibitory potential against ZIKV replication and may be promising for developing affective therapies.


2015 ◽  
Vol 10 (5) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Maryia Mishyna ◽  
Nikolai Laman ◽  
Valery Prokhorov ◽  
Yoshiharu Fujii

Distribution patterns of furocoumarins in fruits of the invasive species Heracleum sosnowskyi Manden. (Sosnowskyi's hogweed) during a cold stratification period were investigated. Angelicin, bergapten, methoxalen and imperatorin were mainly localized in the fruit coats and their content varied depending on the fruit source. Cold stratification treatment (90 days, 2–3°C) reduced the content of furocoumarins in the fruit coats by more than two times, compared with those before stratification. The specific activity of the detected furocoumarins and total activity of crude extracts were evaluated using Lactuca sativa, as acceptor plant. Crude extracts obtained from fruit coats and seeds of H. sosnowskyi suppressed 50% of radicle and hypocotyl growth of lettuce seedlings at the concentration range of 1.0–1.7 mg/mL. The inhibitory activity of angelicin was proved to be the highest compared with the other tested furocoumarins, and the inhibitory activity of crude extracts could be explained mainly by the presence of angelicin. Both, monocots ( Lolium multiflorum, Phleum pratensis, Festuca pratesis, Lolium perenne) and dicots ( Tripholium repens, Trifolium pretense) were found to be sensitive to the exudates of whole H. sosnowskyi fruits. Thus, we assume, that high inhibitory potential of furocoumarins, especially angelicin, at high seed productivity of H. sosnowskyi might have an ecological significance in plant-plant interaction.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Getachew Mulatu

The study aimed to determine the phytochemicals and to assess the antibacterial activities of crude extracts of different parts of Calpurnia aurea against Staphylococcus aureus, Streptococcus pyogenes, Listeria monocytogenes, Escherichia coli O157 H:7, Salmonella typhi, and Campylobacter jejuni. The fresh and healthy leaves, barks, stems, and roots of the plant parts were collected, herbarium, dried, and grounded, and bioactive compounds were extracted by ethanol (99%) and water. Mass of crude extracts was determined by using the Whatman No. 1 filter paper and rotary evaporator. Major secondary metabolites were also screened using phytochemical screening tests. Antibacterial activities (inhibition zones, mm) and minimum inhibition concentrations (MIC) were evaluated using agar-well diffused methods and agar dilution methods, respectively. The antibiotics ciprofloxacin, amoxicillin, penicillin, and tetracycline were used as positive controls at concentrations of 0.1 mg/ml and 0.2 mg/ml, while distilled water was used as the negative control. All the crude extracts were tested triplet (3x) for antibacterial activities against selected bacterial strains with two different concentrations 25 and 50 mg/ml and analyzed to compare the mean ± standard deviation between triplets. The results revealed that ethanol extracts showed high crude mass extracts, antibacterial activities, and major secondary metabolites such as alkaloids, tennis, flavonoids, saponins, steroids, and phlobatannins compared with aqueous extracts. Among antibiotics used, penicillin showed resistance to S. aureus and E. coli O157 H:7. C. jejuni was found to be the most susceptible bacterium to ethanol extracts’ leaves, barks, and stems with MIC 3.125 mg/ml, whereas S. aureus was the least susceptible to all crude extracts. The study provided the traditional and scientific basis of Calpurnia aurea used against some bacterial diseases.


2002 ◽  
Vol 34 (4) ◽  
pp. 351-359 ◽  
Author(s):  
Elfie Stocker-Wörgötter ◽  
John A. Elix

AbstractThe study aimed to optimize culture conditions and nutrient requirements for theproduction of secondary metabolites by the cultured mycobiont Lobaria spathulata. This species proved to be an excellent model system for such studies, as the complete chemosyndromefound in the natural lichen thallus was repeatedly formed in the cultured mycobiont with differentiated, aerial mycelia. Nutrient media containing the disaccharide, sucrose, were found to favour both rapid growth and the production of typical lichen substances. Higher proportions of the secondary compounds were detected in the developing mycobiont than in mature lichen thalli.


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