Rapid Spectrophotometric Method for Assessing Hydroperoxide Formation from Terpenes in Essential Oils upon Oxidative Conditions

Development of a near-infrared fluorescent probe for in situ monitoring of hydrogen peroxide in plants

In plants, hydrogen peroxide (H2O2), one of the significant reactive oxygen species, plays a dual function. Investigating its concentration is essential for understanding its production and scavenging mechanisms in plants. In this study, a near-infrared fluorescent probe (Cy-Bo) was developed, which is based on the hemicyanine compound. By introducing indole salts into the oxygenated anthraquinone structure, the conjugated system is expanded, enabling the probe to emit long-wavelength fluorescence in the near-infrared region, thereby minimizing interference from other biomolecules in plant tissues (λex = 650 nm, λem = 720 nm). As for the specific recognition of H2O2, the pinacol phenylborate ester was selected to be the recognition group. It shows good linearity (R2 = 0.998) in the concentration range of 0.5-100 μM, with a detection limit of 0.07 μM. Furthermore, this probe Cy-Bo has been used for in vivo fluorescence imaging in plants due to its good bio-penetration and in-situ imaging capabilities. The results reveal a significant increase in H2O2 concentration in Arabidopsis thaliana under progressively increasing drought, high-temperature, and salt stress. This tool provides a non-invasive, in situ imaging method for detecting H2O2 in plants, which has a fast response, easy operation, and high sensitivity. It enables visual monitoring of H2O2 fluctuations and aids in advancing physiological and pathological studies related to H2O2.

Oxidation of myrtenol to myrtenal epoxide in a porphyrin-based photocatalytic system - A novel terpene alcohol derivative with antimicrobial and anticancer properties

Biomimetic catalysis using porphyrins enables gentle oxidation of terpenes with molecular oxygen and light. This study explores the photooxidation of (-)-myrtenol under visible light to synthesize new terpenoid products with promising biological activity. Among the porphyrins tested, tetraphenylporphyrin (H2TPP) exhibited the highest catalytic efficiency and stability in chloroform, producing myrtenal epoxide (ME) as the main product (with a molar conversion of myrtenol of 66.2 %), confirmed by NMR and MS analyses. Other substrates, i.e. perillyl alcohol and trans-pinocarveol, did not yield redox products. The antimicrobial activity of ME was assessed against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans using Disk Diffusion, Minimal Inhibitory Concentration, and Minimal Biofilm Eradication Concentration assays (using liquid ME) and the Quantitative Assay for Measuring the Antibiofilm Activity of Volatile Compounds (using volatile ME). Overall, ME displayed higher antimicrobial activity than myrtenol in the majority of the tests applied. The strongest effects were observed against C. albicans, followed by S. aureus, while the weakest activity was exhibited against Gram-negative bacteria. ME also showed cytotoxic effects on human colorectal cancer cells (HT-29) with significantly higher biological activity than that of (-)-myrtenol. Notably, ME at lower concentrations (5-50 µg/ml) promoted proliferation of normal cells while inhibiting the viability and proliferation of cancer cells. Porphyrin-based photooxidation is a sustainable method for converting biorenewable terpene feedstocks into new compounds that can be used in cancer treatment and antimicrobial therapy.

An Optimized Terpene Profile for a New Medical Cannabis Oil

The purpose of this analytical study was to develop an advanced formulation of medical Cannabis oil (MCO) comparing the chemical profile of different extracts obtained with two existing methods (SIFAP and CALVI) and one original upgraded (CERFIT) method. Preparation methods were applied with varying solvent, temperature, and duration of the decarboxylation and extraction steps. HPLC-MS/MS TSQ and GC/FID-HS analyses were performed to investigate cannabinoid and terpene contents in the three oil extracts. Cannabinoids profile remained comparable between the formulations. CERFIT extracts exhibited a superior quantity of total terpene hydrocarbon forms (e.g., limonene and α-pinene) with no degradation occurrence (i.e., oxidized terpenes not quantifiable). Thus, this new method optimized the phytochemical profile of the MCO presenting a value opportunity to obtain a standardized high-level therapeutic product.

Evaluation of the Effect of Essential Oil Addition on the Quality Parameters and Predicted Shelf Life of Potato Yogurt

ABSTRACT

Potato, the third most important food crop worldwide, is rich in nutrients but low in protein. In contrast, milk is rich in protein. Yogurt produced through the cofermentation of potatoes and milk is a highly nutritious food. The quality and shelf life of yogurt are important topics in the dairy industry. The objective of this study was to explore the effect of the addition of essential oil (EO) on the shelf life and quality of potato yogurt. The antimicrobial effects of several EOs, the effect of perilla leaf EO (PLEO) concentration on potato yogurt, and the volatile flavor components of PLEO and PLEO potato yogurt were evaluated. The effects of storage time and temperature on the pH, microbial counts, and sensory characteristics of PLEO potato yogurt also were analyzed to establish a shelf-life model. PLEO had an antimicrobial effect and was the appropriate EO for use in the potato yogurt. A total of 69 compounds were detected in PLEO, and limonene was the main compound. PLEO had an effect on the pH, sensory characteristics, and viable bacterial counts of potato yogurt during storage. The optimal concentration of added PLEO was 0.04%. PLEO had considerable influence on volatile flavor components, and the consumer acceptance of 0.04% PLEO potato yogurt was higher than that of potato yogurt without PLEO in the later stage of storage. The shelf life of potato yogurt with PLEO was 6 days longer than that of the control yogurt. PLEO also improved the concentrations of active terpene substances in potato yogurt. The prediction models based on pH and sensory scores at 5°C were established as A = A0e0.00323t and A = A0e0.00355t, respectively. Comparison of the accuracy factor and the deviation factor of the models revealed that the sensory prediction model was more accurate than the pH prediction model. The results of this study provide theoretical and data support for the industrial development of yogurt with EOs, including extension and prediction of its shelf life.

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