Evaluation of Different Drying Treatments with Respect to Essential Oil Components, Phenolic and Flavonoid Compounds, and Antioxidant Capacity of Ajowan (Trachyspermum ammi L.).

Ajowan (Trachyspermum ammi L.) is considered a valuable spice and medicinal herb. In this study, the essential oil content and composition of the aerial parts of ajowan were investigated under different drying treatments (sun, shade, oven at 45 °C, oven at 65 °C, microwave, and freeze drying). Moreover, the phenolic content, flavonoid content, and antioxidant capacity of samples were also assessed. Fresh samples produced the highest essential oil content (1.05%), followed by those treated under sun (0.7%) and shade drying (0.95%). Based on gas chromatography-mass spectrometry (GC-MS), thirty compounds were determined in which thymol (34.84-83.1%), carvacrol (0.15-32.36%), p-cymene (0.09-13.66%), and γ-terpinene (3.12-22.58%) were the most abundant. Among the drying methods, freeze drying revealed the highest thymol content, followed by drying in a 45 °C oven. The highest TPC (total phenolic content) and TFC (total flavonoid content) were obtained in the fresh sample (38.23 mg TAE g-1 dry weight (DW)) and in the sample oven-dried at 45 °C (7.3 mg QE g-1 DW), respectively. Based on the HPLC results, caffeic acid (18.04-21.32 mg/100 gDW) and ferulic acid (13.102-19.436 mg/100 g DW) were the most abundant phenolic acids, while among flavonoids, rutin constituted the highest amount (10.26-19.88 mg/100 gDW). Overall, freeze drying was the most promising method of drying for preserving the phenolic (TPC) and flavonoid (TFC) compounds and oil components.

Analytical Method for Quantifying Monoterpenoids (p-Cymene and Myrcene) in Nanoemulsions Using High-Performance Liquid Chromatography.

BACKGROUND: Myrcene and cymene, aromatic monoterpenes found in plants and essential oils, possess distinctive aromatic qualities. However, their volatility and limited solubility pose challenges in precise handling and formulation. Meanwhile, nanoemulsions emerge as promising drug delivery systems, improving the bioavailability and stability of these active ingredients. OBJECTIVE: This article aimed to develop an HPLC method for the quantification of two monoterpenoids, p-cymene and myrcene, in nanoemulsions. METHOD: The method used a Phenomenex® Synergi™ Fusion-RP column (150 mm × 4.6 mm id, 4 µm particle size) on an HPLC system with isocratic elution. The mobile phase was composed of acetonitrile and water (60:40, v/v) and was validated in terms of specificity, linearity, accuracy, precision, robustness, and selectivity. RESULTS: The method provided accurate and precise results with a correlation coefficient of 0.999 and RSD values of less than 2%. The method can be used for quality control of nanoemulsions containing these monoterpenoids and as a reference for future studies on their efficacy and stability. CONCLUSIONS: The study demonstrates the feasibility of using HPLC for the quantification of monoterpenoids in nanoemulsions and its potential as a quality control tool for nanoemulsion-based drug delivery systems. HIGHLIGHTS: The method's accuracy, precision, and reliability, as evidenced by high correlation coefficients and low RSD values, underscore its suitability for ensuring the consistent formulation of these monoterpenoid-containing nanoemulsions, while also serving as a reference point for future research endeavors in this field.

Chemical composition of the essential oils from two subspecies of Protium heptaphyllum / Composição química do óleo essencial de duas subespécies do Protium heptaphyllum

Qualitative and quantitative analyses of the volatile constituents from resin of Protium heptaphyllum (Aubl.) Marchand subsp. ulei (Swat) Daly (PHU), and Protium heptaphyllum (Aubl.) Marchand subsp. heptaphyllum (PHH), Burseraceae were performed using GC-MS and GC-FID. The resins were collected around the city of Cruzeiro do Sul, state of Acre, Brazil. Essential oils from the two subspecies were extracted by hydrodistillation with a yield of 8.6 percent (PHU) and 11.3 percent (PHH); the main components were terpinolene (42.31 percent) and p-cymene (39.93 percent) for subspecies ulei (PHU) and heptaphyllum (PHH), respectively.

As análises qualitativa e quantitativa dos óleos essenciais obtidos das resinas das espécies Protium heptaphyllum (Aubl.) Marchand subespécie ulei (Swat) Daly (PHU) e Protium heptaphyllum (Aubl.) Marchand subespécie heptaphyllum (PHH), Burseraceae, foram realizadas utilizando cromatografia em fase gasosa acoplado a um espectrômetro de massa (CG-EM) e cromatografia a gás com detector de chama (CG-DIC). As resinas foram coletadas no Município de Cruzeiro do Sul, Acre, Brasil. O óleo essencial das oleoresinas foi extraído por hidrodestilação fornecendo rendimento 8,6 por cento para PHU e 11,3 por cento para PHH. Os monoterpenos terpinoleno (42.31 por cento) e p-cimeno (39.93 por cento) foram os constituintes principais para PHU e PHH, respectivamente.