No abstract

Pyrroles and its fused forms possess antimicrobial activities, they can easily interact with biomolecules of living systems. A series of substituted pyrroles, and its fused pyrimidines and triazines forms have been synthesised, all newly synthesised compound structures were confirmed by spectroscopic analysis. Generally, the compounds inhibited growth of some important human pathogens, the best effect was given by: 2a, 3c, 4d on Gram-positive bacteria and was higher on yeast ( C. albican s), by 5c on Gram-negative bacteria and by 5a then 3c on filamentous fungi (A. fumigatus and F. oxysporum ). Such results present good antibacterial and antifungal potential candidates to help overcome the global problem of antibiotic resistance and opportunistic infections outbreak. Compound 3c gave the best anti-phytopathogenic effect at a 50-fold lower concentration than Kocide 2000, introducing a safe commercial candidate for agricultural use. The effect of the compounds on DNA was monitored to detect the mode of action.

Resveratrol (3,4,5-trihydroxystilbene) is a naturally occurring polyphenolic stilbene compound produced by certain plant species in response to biotic and abiotic factors. Resveratrol has sparked a lot of interest due to its unique structure and approved therapeutic properties for the prevention and treatment of many diseases such as neurological disease, cardiovascular disease, diabetes, inflammation, cancer, and Alzheimer’s disease. Over the last few decades, many studies have focused on the production of resveratrol from various natural sources and the optimization of large-scale production. Endophytic fungi isolated from various types of grapevines and Polygonum cuspidatum, the primary plant sources of resveratrol, demonstrated intriguing resveratrol-producing ability. Due to the increasing demand for resveratrol, one active area of research is the use of endophytic fungi and metabolic engineering techniques for resveratrol’s large-scale production. The current review addresses an overview of endophytic fungi as a source for production, as well as biosynthesis pathways and relevant genes incorporated in resveratrol biosynthesis. Various approaches for optimizing resveratrol production from endophytic fungi, as well as their bio-transformation and bio-degradation, are explained in detail.

Mesoporous silica nanoparticles (MSNs) can promote the solubility and absorption of pesticides by plants and are widely used as a delivery system to improve the efficacy of pesticide applications. In this study, MSNs with 20 nm particle size were produced. Additionally, a water-soluble chitosan (CS) derivative, here called N-(2-Hydroxyl) propyl-3- tri-methyl-ammonium CS chloride (HTCC) was produced and used to cap the outer surface of the MSNs preloaded with the pesticide fludioxonil (Flu). The HTCC coating layers resulted in a pesticide loading efficiency of 84% on the MSNs in comparison to a loading efficiency of 20% of uncoated particles. A comparative in vitro analysis indicated that Flu@MSNs20nm-HTCC loaded with a 0.05 mg/L dose of fungicide had significant higher fungicidal activity than the same fungicide at 1 mg/L dose against F. oxysporum f. sp. radicis-lycopersici (FORL). Moreover, after an initial burst, MSNs20nm-HTCC kept releasing Flu for 21 d, compared to an activity of 7 d associated with the direct release of Flu. Greenhouse data showed that 0.1 mg/L Flu applied through MSNs20nm-HTCC is sufficient to reduce Fusarium crown and root rot disease severity to a value of less than 6% in tomato plants, without any noticeable phytotoxicity after 70 d. In comparison, 1.56 mL/L of the fungicide are required to reach a 27% disease severity level. Thus, we suggest that HTCC-decorated MSNs20nm has a great potential as a nanodelivery systems for agrochemical applications. We also suggest that this work contributes to the notion that agro-nanotechnology is a powerful, environmentally-safe and cost-effective approach for a sustainable and long term protection of plants from disease.

Lignin, a naturally occurring biopolymer, is produced primarily as a waste product by the pulp and paper industries and burned to produce electricity. Lignin-based nano- and microcarriers found in plants are promising biodegradable drug delivery platforms. Here, we highlight a few characteristics of a potential antifungal nanocomposite consisting of carbon nanoparticles (C-NPs) with a defined size and shape containing lignin nanoparticles (L-NPs). Spectroscopic and microscopic studies verified that the lignin-loaded carbon nanoparticles (L-CNPs) were successfully prepared. Under in vitro and in vivo conditions, the antifungal activity of L-CNPs at various doses was effectively tested against a wild strain of F. verticillioides that causes maize stalk rot disease. In comparison to the commercial fungicide, Ridomil Gold SL (2%), L-CNPs introduced beneficial effects in the earliest stages of maize development (seed germination and radicle length). Additionally, L-CNP treatments promoted positive effects on maize seedlings, with a significant increment in the level of carotenoid, anthocyanin, and chlorophyll pigments for particular treatments. Finally, the soluble protein content displayed a favorable trend in response to particular dosages. Most importantly, treatments with L-CNPs at 100 and 500 mg/L significantly reduced stalk rot disease by 86% and 81%, respectively, compared to treatments with the chemical fungicide, which reduced the disease by 79%. These consequences are substantial considering the essential cellular function carried out by these special natural-based compounds. Finally, the intravenous L-CNPs treatments in both male and female mice that affected the clinical applications and toxicological assessments are explained. The results of this study suggest that L-CNPs are of high interest as biodegradable delivery vehicles and can be used to stimulate favorable biological responses in maize when administered in the recommended dosages, contributing to the idea of agro-nanotechnology by demonstrating their unique qualities as a cost-effective alternative compared to conventional commercial fungicides and environmentally benign nanopesticides for long-term plant protection.