Exploratory evaluation supported by experimental and modeling approaches of Inula viscosa root extract as a potent corrosion inhibitor for mild steel in a 1 M HCl solution.

The corrosion of metals poses a threat to the economy, the environment, and human health due to undesirable reactions and contaminated products. Corrosion inhibitors, including natural products, can play a key role in protecting metallic materials, especially under challenging conditions. In this study, the roots of the Inula viscosa plant were examined for their ability to act as corrosion inhibitors in a 1 M hydrochloric acid (HCl) solution. Different extracts of the plant were evaluated for their corrosion inhibition capacity in a 1 M HCl solution. The effectiveness of different plant extracts was assessed, including an aqueous extract, an ethanolic extract, and a combined water-ethanol extract. Compounds present in the roots of Inula viscosa were identified using high-performance liquid chromatography. The electrochemical properties of the extracts were studied using various techniques such as open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization. Additionally, surface analysis after immersion was performed using scanning electron microscopy. Electrochemical data revealed that Inula viscosa root (IVR) extracts acted as mixed-type corrosion inhibitors with pronounced cathodic characteristics. The inhibitory efficiency was closely related to the concentration of Inula viscosa (I. viscosa), showing a significant increase with higher concentrations. This resulted in a decrease in corrosion current and an increase in polarization resistance. Notably, inhibitory efficiency reached high levels, up to 97.7% in mixed extract which represents a mixture between water and ethanol. In our study, it was observed that the mixed extract (water + ethanol) allowed for a greater corrosion inhibition compared to the other solvents studied, 97.7%. Surface analyses confirmed the formation of an organic film layer on the steel surface, attributed to the bonding of functional groups and heteroatoms in I. viscosa components. Therefore, this study paves the way for the potential integration of I. viscosa as a promising corrosion inhibition material, offering durable protection against steel corrosion and opening avenues for various related applications.

Analysis of Primary and Secondary Metabolites, Physical Properties, Antioxidant and Antidiabetic Activities, and Chemical Composition of Rosmarinus officinalis Essential Oils under Differential Water Stress Conditions.

This study investigated the effects of varying water stress levels on Rosmarinus officinalis essential oils (EO). Three samples (S1, S2, and S3) were cultivated under different stress levels (40, 60, and 80%). Increased water stress led to changes in primary and secondary metabolites, EO contents, and physical properties. Antioxidant activity varied, with S2 exhibiting the highest IC50 value. In terms of antidiabetic activity, S2 showed robust α-amylase inhibition, while S3 displayed a commendable influence. For α-galactosidase inhibition, S3 had a moderate effect, and S2 stood out with increased efficacy. Gas chromatography-mass spectrometry analysis revealed stress-induced changes in major compounds. The study enhances the understanding of plant responses to water stress, with potential applications in antioxidant therapy and diabetes management. The findings emphasize the importance of sustainable water management for optimizing the EO quality in its various uses.

Impact of Climate Change on the Chemical Compositions and Antioxidant Activity of Mentha pulegium L.

A central position in Moroccan ethnobotany is held by the Mentha genus, serving as a vital reference for aromatic and medicinal plants within the Lamiaceae family. The profound importance of Mentha species in the daily lives of Moroccans is recognized, and the primary objective of this study is to assess the impact of rising temperatures and decreasing precipitation on the primary and secondary metabolites of Mentha pulegium under the following climatic conditions: sample 1, cultivated under standard temperature and precipitation conditions during the first year; sample 2, subjected to an 8 °C temperature increase and a 25% reduction in water supply; and sample 3, exposed to a 12 °C temperature rise and a 50% decrease in water availability. Phytochemical screening results reveal a progressive decline in primary metabolites from sample 1 to sample 3 due to the increase in temperature and decrease in precipitation. Conversely, a distinct trend is observed in secondary metabolites and the yield of essential oil, increasing from sample 1 to sample 2 as the temperature rises and precipitation decreases. Remarkably, in sample 3, the yield of essential oil decreases as climatic conditions further deteriorate. Additionally, GC analysis demonstrates that modifications in the chemical compositions of essential oils occur because of the disruption of climatic parameters, particularly in the major compounds. Similarly, changes in climatic parameters significantly influence antioxidant activity, with sample 2 exhibiting the highest activity, as reflected by an IC50 value (half-maximal inhibitory concentration) of 14,874.04 µg/mL, followed by the third sample at 8488.43 µg/mL, whereas the first sample exhibits the lowest activity at 4505.02 µg/mL. In summary, the complex relationship between climatic factors and the chemical composition of Mentha pulegium is highlighted by our experiment, emphasizing its implications for medicinal properties within an ecological context.