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•Three new highly oxygenated azaphilones were isolated from Penicillium sp. LZUC-S1.•Compound 1 belongs to a rare class of azaphilone possessing an acetonyl at C-8.•Some azaphilones ...showed antifungal activity against four phytopathogenic fungi.
Three new highly oxygenated azaphilones, penicilphilones A–C (1–3), along with four known analogues (4–7) were isolated from the culture of Penicillium sp. LZUC-S1. Their structures were elucidated by detailed spectroscopic data interpretation, electronic circular dichroism (ECD) calculation, and DP4+ analysis. 1 belongs to a rare class of azaphilone possessing an acetonyl at C-8. 2, 5, and 6 are uncommon azaphilones holding a chain with four carbons at C-8. Compounds 1, 3, and 4 showed potent activities against the selected phytopathogenic fungi with inhibitory rates ranging from 49.8 to 78.6 % at 50 μg/mL. In addition, a putative biogenetic pathway for compounds 1, 2, 5, and 6 was proposed.
In this work, the antifungal activity of rhamnolipids produced by Pseudomonas aeruginosa #112 was evaluated against Aspergillus niger MUM 92.13 and Aspergillus carbonarius MUM 05.18. It was ...demonstrated that the di-rhamnolipid congeners were responsible for the antifungal activity exhibited by the crude rhamnolipid mixture, whereas mono-rhamnolipids showed a weak inhibitory activity. Furthermore, in the presence of NaCl (from 375 mM to 875 mM), the antifungal activity of the crude rhamnolipid mixture and the purified di-rhamnolipids was considerably increased. Dynamic Light Scattering studies showed that the size of the structures formed by the rhamnolipids increased as the NaCl concentration increased, being this effect more pronounced in the case of di-rhamnolipids. These results were confirmed by Confocal Scanning Laser Microscopy, which revealed the formation of giant vesicle-like structures (in the µm range) by self-assembling of the crude rhamnolipid mixture in the presence of 875 mM NaCl. In the case of the purified mono- and di-rhamnolipids, spherical structures (also in the µm range) were observed at the same conditions. The results herein obtained demonstrated a direct relationship between the rhamnolipids antifungal activity and their aggregation behaviour, opening the possibility to improve their biological activities for application in different fields.
Recently, there has been considerable attention towards the production of environmentally friendly nanoparticles (NPs). In this investigation, the successful synthesis of cerium oxide nanoparticles ...(CeO2 NPs) was achieved by employing an eco-friendly technique that utilized an extract from the leaves of local plant quinoa (Chenopodium quinoa L.). The synthesized CeO2 NPs were subjected to characterization using state-of-the-art methods. The prepared CeO2 NPs contained a round shape with clusters and have a size of 7–10 nm. To assess how effective CeO2 NPs derived from C. quinoa were against Ustilago tritici, a fungal disease that negatively affects wheat crop globally, a study was performed on two varieties of wheat crop comprised of Arooj (V1) and Akber (V2), cultivated under field conditions. CeO2 NPs were applied foliarly twice to the wheat crop at four different concentrations: T0 (0 mg/L), T1 (50 mg/L), T2 (75 mg/L), and T3 (100 mg/L). The results revealed that the control group (T0) exhibited the highest disease severity index (DSI) with a value of 75% compared to the other concentrations of CeO2 NPs on both varieties. At a concentration of 100 mg/L of CeO2 NPs, the DSI dropped to a minimum of 35% and 37% on both V1 and V2 respectively. These findings indicated that an increase in the concentration of CeO2 NPs has a beneficial impact on disease severity. Similar patterns have also been observed with disease incidence (DI), with the greatest efficacy observed at a concentration of 100 mg/L of CeO2 NPs. Our investigation has shown that CeO2 NPs exhibitd significant antifungal potential against U. tritici which may be a promising strategy to mitigate fungal disease and crop losses globally.
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•Chenopodium quinoa leaf extract was used to synthesie CeO2 NPs•Antifungal potential of CeO2 NPs was tested in field grown wheat plants•CeO2 NPs exhibited significant antifungal activity against Ustilago tritici.•CeO2 NPs could be a promising strategy to combat wheat fungal disease
A facile synthesis of a new thiazol-2-amine derivative as antimicrobial agent and condensation with substituted thiourea compounds to afford the corresponding substituted thiazole derivatives in ...excellent yields. All the reactions were completed within less reaction time at reflux temperature. According to the result obtained, the compounds 3b, 3d, 3e, 3f, 3g, 3i, 3l, and 3m were found the leader antimicrobial activity with the highest MIC values. The synthesized compound can be considered to develop new antimicrobial drug candidates. Amongst these, many compounds show better antibacterial and antifungal activity. The compounds 3b, 3d, 3e, 3l, and 3m exhibited significant antibacterial activity against B. subtilis, S. aureus, and E. coli. The compounds 3f, 3g, 3i show significant antifungal against fungal strains i.e., C. albicans, A. flavus and A. niger.
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D-limonene is an important constituent of citrus fruits, such as oranges and lemons, and can be extracted as a natural essential oil for controlling the agricultural pests because of ...its antifungal and insecticidal activities. However, the hydrophobicity of D-limonene hinders its full potential and excellent performance. In this research, the effect of emulsifier type, dosage, and emulsification method on the formation and stability of D-limonene-loaded nanoemulsions was investigated by sample appearance, microstructural observations, droplet size measurement, and multiple light scattering analysis. Nanoemulsions prepared with emulsifier (EL-40) exhibited the highest stability, with an appropriate HLB (Hydrophilic Lipophilic Balance) value of 13.5. The stability of nanoemulsions increased at higher emulsifier dosage from 2% to 6%. Also, nanoemulsions fabricated by dropwise addition of aqueous phase (deionized water) into D-limonene as the oil phase premixed with emulsifier were the most stable samples. The optimized formulation of D-limonene-loaded nanoemulsions was determined as: 10 % D-limonene, 6% EL-40, and 84 % deionized water. The quality indicators of this formulation were acceptable in terms of FAO standards. Finally, D-limonene-loaded nanoemulsions could inhibit the growth of various fungal pathogens, including Pyricularia oryzae (rice blast), Rhizoctonia solani (rice sheath blight), Colletortrichum gloeosporiodes (pepper anthracnose), and Phomopsis amygdali (peach shoot blight). This research provides a practical solution for the formulation of stable and effective nanoemulsions containing D-limonene for the control of agricultural crop diseases.
Mango cv. Manila kernel ethanolic extract (MKE) was assessed in vitro and in mango cv. Ataulfo fruits for antifungal activity against Colletotrichum brevisporum. An optimum MKE with a total phenolic ...content of 461.7 mg gallic acid equivalents/g and DPPH• antioxidant activity of 2919.0 μmol Trolox equivalents/g was obtained by applying high intensity ultrasound, using a solid/liquid of 1/20 g/mL and a sonication time of 30 min. The major phenolic compounds in MKE were mangiferin, chlorogenic acid, myricetin, ferulic acid, quercetin, rutin and caffeic acid. In vitro studies revealed that MKE at 3 g/L produced a mycelial growth inhibition of 100% after 9 d and a spore germination of 0% after 20 h. In contrast, the recommended dosage (2 g/L) of the commercial fungicide thiabendazole achieved a mycelial growth inhibition of 67.6% and a spore germination of 51.4% for the same times. Mango fruits immersed in MKE (3 g/L) aqueous solution for 20 min and inoculated with C. brevisporum (105 spores/mL) presented disease lesions of 0 mm, while when immersed in thiabendazole (2 g/L) the disease lesions were of 4.5 mm, both after 9 d. Thus, MKE may be considered as effective antifungal agent.
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•Mango kernel extract (MKE) from cv. Manila showed high radical scavenging activity.•Ultrasound assisted extraction increased the total phenolic content in the extracts.•Mangiferin, chlorogenic acid and myricetin were the main phenolic compounds found.•Antifungal activity of MKE was higher than that of commercial thiabendazole fungicide.•Development of anthracnose was suppressed for 9 days with MKE at 3 g/L.
The postharvest decay of tomatoes, induced by the pathogen Alternaria alternata during storage, has led to significant economic losses in the tomato industry. This study aimed to explore the effect ...and underlying mechanism of the marine-derived fungus bioactive compound chaetoglobosin D (ChD) against postharvest black spot disease in tomato fruit. In both in vitro and in vivo experiments, ChD was found to effectively inhibit the growth of A. alternata and reduce the lesion area caused by this pathogen. Electron microscopy observations revealed that ChD induces mycelia morphological deformations, increases branching, and disrupts the integrity of cell membrane and certain organelle. Enrichment analysis of transcriptome revealed a notable enrichment of genes associated with oxidoreductase activity and ATPase activity. Similarly, analysis of metabolome showed significant changes in glycerophospholipid metabolism, the pentose phosphate pathway, and the citrate cycle. These findings were further supported by fluorescence staining, increased relative conductivity, ergosterol, malondialdehyde, and hydrogen peroxide content, as well as decreased catalase, superoxide dismutase, ATPase activity, and ATP content. These results suggested that ChD could impact the synthesis of cell membranes, leading to oxidative damage within the mycelia. The application of ChD in preserving fresh tomatoes effectively maintained the quality and flavor of the product, positioning it as a natural agent for mitigating postharvest decay in tomatoes.
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•Chaetoglobosin D (ChD) exhibited inhibitory activity against Alternaria alternata.•ChD could damage the integrity of cell membranes and cause oxidative stress.•ChD could effectively preserve tomato quality and flavor in fresh tomatoes.•ChD has potential as a natural agent for mitigating postharvest decay in tomatoes.
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