Psidium myrtoides O. Berg fruit and leaves: physicochemical characteristics, antifungal activity and chemical composition of their essential oils in different seasons

Green extraction of phenolic compounds from the by-product of purple araçá (Psidium myrtoides) with natural deep eutectic solvents assisted by ultrasound: Optimization, comparison, and bioactivity

The recovery of bioactive compounds is a promising approach for obtaining rich extracts from fruit by-products. This study investigated the influence of Natural Deep Eutectic Solvents (NADES) and Ultrasound-Assisted Extraction (UAE) on the phenolic content, antioxidant capacity, and in vitro antidiabetic activity of Psidium myrtoides by-product. Among eight NADES evaluated based on choline chloride, NADES ChCl:Gly (1:2) was selected for its efficiency in extracting total phenolic compounds (TPC) with high antioxidant capacity. The optimized conditions were 61 °C, a solid-liquid ratio of 100 mg 5 mL-1, and a 60-minute extraction time. ChCl:Gly exhibited superior TPC recovery (2.6-fold greater effectiveness) compared to the 60 % hydroethanolic solution. Twenty-six phenolic compounds were identified, including significant levels of catechin (336.48 mg g-1) and isoquercetin (26.09 mg g-1). Phenolic acids, such as p-anisic acid (5.47 mg g-1) and methoxyphenylacetic acid (0.23 mg g-1), were identified for the first time in the purple araçá by-product. The ChCl:Gly extract demonstrated the highest bioactivity, showcasing antioxidant and antidiabetic capacities. This study introduces an innovative and sustainable alternative for recovering phenolic compounds from fruit by-products, offering enhanced recovery efficiency and/or selectivity compared to organic solvents.

Determining of chemical composition, anti-pathogenic and anticancer activity of Mentha longifolia essential oil collected from Iran

In this study, three different ecotypes of M. longifolia collected from Lorestan province, Iran. three habitats including Khorramabad (ecotype 1), Aleshtar (ecotype 2), and Delfan (ecotype 3) counties (ecotype 3) were selected. In addition to analysing the chemical composition of the essential oils, for the first time, the effects of essential oils of these ecotypes against plant pathogenic bacterial including Erwinia amylovora and Pseudomonas syringae together with Bacillus subtilis, a biocontrol agent, and viability of colon tumour cell (SW742) was evaluated. Results showed that ecotype 1 had the highest concentration of the essential oil. All three bacteria showed the same level of sensitivity to the essential oils of M. longifolia extracted from three different ecotypes. Considering the findings of the effects of essential oils on SW742 tumour cell viability, we can suggest that M. longifolia essential oil obtained from ecotype 3 can be used to reduce the cell viability of SW742 tumour cells. It can be concluded that M. longifolia essential oil can be used to reduce tumour cell viability and their anti-microbial activity against plant pathogens.

Larvicidal and Fungicidal Activity of the Leaf Essential Oil of Five Myrtaceae Species

Myrtaceae is one of the most diverse and abundant botanical families, exhibiting wide diversity in the chemical composition of essential oils (EOs). EOs have various biotechnological applications such as controlling the populations of organisms that negatively impact humans. This study aimed to extract EOs from Myrtaceae species, chemically characterize them, and evaluate their larvicidal and fungicidal effects. EOs were extracted from the leaves of Eugenia brasiliensis, Eugenia uniflora, Psidium cattleyanum, Psidium guajava, and Syzygium cumini by hydrodistillation for 3 h and characterized by chromatographic analysis. Larvaes of Aedes aegypti and colonies of Fusarium oxysporum were subjected to increasing EO concentrations to determine the larvicidal and fungicidal potential. The EOs of Eugenia and Psidium species are primarily composed of sesquiterpenes (>80 %), whereas S. cumini EO is rich in monoterpenes (more than 60 %). The Eugenia species had similar amounts of oxygenated monoterpenes, which may explain their higher larvicidal potential compared to other species, with CL50 of 86.68 and 147.46 PPM, respectively. In addition to these two study species, S. cumini showed a high inhibition of fungal growth, with more than 65 % inhibition. We demonstrated that the actions of five EOs from Myrtaceae with different biological activities are associated with chemical diversity.

Essential oil from Sabina chinensis leaves: A promising green control agent against Fusarium sp

Sabina chinensis is a woody plant with important ecological functions in different regions of China, but its essential oils (EO) against plant pathogenic fungi remain largely undetermined. The purpose of our study was to assess the chemical composition and antifungal activity of S. chinensis EO based on optimization of the extraction process. In this study, an actionable and effective model with the experimental results and identified optimum conditions (crushing degree of 20 mesh, liquid-solid ratio of 10.1:1, immersion time of 9.1 h) was established successfully to achieve an extraction yield of 0.54%, which was basically consistent with the theoretical value. A total of 26 compounds were identified using headspace gas chromatography-mass spectrometry (GC-MS) and showed that the major constituent was β-phellandrene (26.64-39.26%), followed by terpinen-4-ol (6.53-11.89%), bornyl acetate (6.13-10.53%), etc. For Petri plate assays, our experiments found for the first time that S. chinensis EO revealed high and long-term antifungal activity against the tested strains, including Fusarium oxysporum and Fusarium incarnatum, at EC₅₀ values of 1.42 and 1.15 µL/mL, which especially reached approximately 76% and 90% growth inhibition at a dose of 0.2 µL/mL, respectively. Furthermore, the antifungal activity of EO from different harvest periods showed remarkable variation. The orthogonal partial least-squares discriminant analysis (OPLS-DA) method revealed 11 metabolites with chemical marker components, and 5 of its potential antifungal activities, terpinen-4-ol, α-terpineol, α-elemol, γ-eudesmol, and bornyl acetate, were strongly correlated with the mycelial inhibition rate. In total, this study explored the antifungal activity of EO against root rot fungus as a potential fungicide and provided valuable information into developing potential products from natural agents.