Exploring the Chemical Landscape and Biological Potentials of Rosmarinus officinalis Essential Oil: a GC Analysis Approach

Abstract

This article presents an analysis of the chemical constituents, antimicrobial efficacy, and antioxidant activity of the essential oil extracted from leaves of Rosmarinus Officinalis, commonly referred to as Rosemary, originating from Hamedan province in Iran. The essential oil was obtained by hydrodistillation method from the sample purchased from the market (LRM) and those cultivated in the university garden (LRU). The research employed Gas Chromatography/Mass Spectrometry (GC/MS) analysis to examine the chemical composition of the obtained essential oils. The antimicrobial efficacy was evaluated by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) via a sequence of microdilutions, while the DPPH assay was used to assess the antioxidant activity. Standard methods determined the ash contents including total ash and acid-insoluable ash. The chemical composition of the essential oils showed some variations. 1,8-cineol, borneol, and camphor were the main components in LRM, while 1,8-cineol and α-pinene were the major constituents of LRU. In the case of microbial tests, LRM showed the best efficacy on Pseudomonas aeroginosae(SA) and LRU had the highest efficacy on Methicillin-resistant Staphylococcus aureus (MRSA). The research exhibited the comparable antioxidant activity of essential oils derived from different plant variations, noting that these activities were not as potent as the positive control. The total ash content of LRM was higher than that of LRU, which indicates impurities in the first sample. The study further explored the variations in these characteristics based on the plant's conditions (purchased or cultivated). The presence of different components in the essential oils from various sources may contribute to the observed variations in biological properties. The researchers recommend further extensive investigations into the chemical constituents and their relative abundance in R. officinalis essential oil to enhance understanding of its therapeutic potential and industrial applications.