Chemical Profile of the Volatile Constituents and Antimicrobial Activity of the Essential Oils from Croton adipatus, Croton thurifer, and Croton collinus

The aim of this study was to determine the volatile phytochemical constituents and evaluate the antimicrobial activity of the essential oils of the leaves from Croton adipatus, Croton thurifer, and Croton collinus. Essential oils were extracted by hydro-distillation using the Clevenger extractor and the phytochemical analysis was determined by Gas chromatography-Mass Spectrometry (GC-MS). The antimicrobial activity was assessed using the agar diffusion and colorimetric broth microdilution methods against Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 9027, and Candida albicans ATCC The essential oils from C. adipatus, C. thurifer, and C collinus had 46, 38, and 35 volatile constituents respectively. The main compounds determined in C. adipatus were β-myrcene (18.34%), while in C. collinus was β-caryophyllene (44.7%), and in C. thurifer was an unknown component (C₁₀H₁₆: 22.38%). Essential oil of C. adipatus showed a MIC against B. subtilis (286.4 µg/mL) and C. albicans (572.8 ± 0 µg/mL); C. thurifer against S. aureus (296.1 ± 0 µg/mL) and B. subtilis (148 ± 0 µg/mL); and C. collinus against B. subtilis (72 ± 0 µg/mL) and C. albicans (576.2 ± 0 µg/mL). The three essential oils of Croton species demonstrated in vitro antimicrobial activity against a strain of bacteria or fungi.