Integrated Botanical and Phytochemical Characterization of Santolina chamaecyparissus L. and Evaluation of its Antimicrobial Activity.

OBJECTIVES: Santolina chamaecyparissus L. is an aromatic medicinal plant with reported phytochemical and biological potential. This study aimed to characterize the botanical and phytochemical features of S. chamaecyparissus and to perform a preliminary screening of the antimicrobial activity of its methanolic extract against selected bacterial and fungal microorganisms. MATERIALS AND METHODS: In this experimental laboratory study, the morphological and anatomical characteristics of the aerial parts were examined using standard pharmacognostic, histological, and scanning electron microscopic methods. The essential oil was obtained by hydrodistillation, and the methanolic extract was prepared by maceration with 90% methanol. Volatile constituents were analyzed by gas chromatography-tandem mass spectrometry, while phenolic compounds were identified and quantified by liquid chromatography-tandem mass spectrometry. Preliminary antimicrobial activity was screened against five bacterial and two fungal strains using the agar well diffusion method. RESULTS: The plant exhibited characteristic xeromorphic features, including amphistomatic and isobilateral leaves, multilayered palisade parenchyma, anomocytic stomata, and dense non-glandular trichomes. The essential oil yield was 0.46%, and 33 volatile constituents were identified. Artemisia ketone (55.96%) and camphor (20.84%) were the major components. The methanolic extract yield was 14.40%, with chlorogenic acid (6733.85 μg/g dry extract) and quinic acid (6521.37 μg/g dry extract) identified as the predominant quantified compounds. The extract showed its strongest antimicrobial activity against Staphylococcus aureus, with inhibition zones of 8.00, 11.00, and 11.66 mm at concentrations of 5, 10, and 20 mg/mL, respectively. More limited activity was observed against Enterobacter hormaechei and Candida albicans, while the effects against the remaining microorganisms were weak or close to baseline. CONCLUSION: S. chamaecyparissus possesses distinctive botanical features and a chemically rich profile characterized by an artemisia ketone-and camphor-dominant essential oil and a chlorogenic acid- and quinic acid-rich methanolic extract. The preferential activity against S. aureus suggests selective anti-gram-positive potential. However, the limited spectrum of activity and the absence of minimum inhibitory and bactericidal concentration analyses restrict the direct interpretation of its antimicrobial efficacy. Further studies using quantitative antimicrobial methods and bioactivity-guided fractionation are warranted.