Influência da sazonalidade nos constituintes químicos, atividade antimicrobiana e antioxidante das partes aéreas de Baccharis articulata (Lam) Pers e Achyrocline satureioides (Lam.) DC.

Abstract

In this study seasonal variation on oil yields and composition, antioxidants activities, toxicity from Artemia salina and antimicrobial activities, from aerial parts of Achyroclines satureoides and Baccharis articulata were investigated. Maximum amount of the hydro-distilled essential oils in spring (0.10%; m/m) and winter (0.43%; m/m) were observed to A. satureioides and B. articulata, respective. Essential oils were analyzed by GC/MS. The compounds a-pinene (28.5 a 41.7%) and (E)- caryophyllene (29.8 a 38.5) were the most abundant component in the all season for A. satureioides. The b-pinene (23.1% a 32.1%), limonene (8.45 a 11.2%), espatulenol (9.31 a 10.9%) and (E)-caryophyllene (4.61 a 7.80%) were the most abundant component for B. articulata. For both species a variation was observed in the total flavonoids content, express in quercetin and antioxidant activity as measurements by DPPH٠ (1,1 diphenyl 2 picrylhydrazyl) free radical-scavenging ability. Regarding to toxicity, the minor CL50 (μg mL-1) was observed in the spring, where the major total flavonoids contents to A. satureioides. To B. articulata, the essential oil and raw methanolic extract were considered non-toxic. Antimicrobial activity measurement of determination of minimum inhibitory concentration (MIC) varied significantly (p<0,05) with different seasons. Autumn and winter were more significant than other season (MIC 37.9 μg mL-1 in autumn and 38.4 μg mL-1 in winter) against bacterial strains Staphylococcus epidermidis ATCC11228; 37.9 μg m -1 (autumn) and 76.8 μg mL-1 (winter) against bacterial strains Bacillus cereus ATCC11778 and 37.9 μg mL-1 (autumn) and 76.8 μg mL-1 (winter) against bacterial strains Klebsiella pneumoniae ATCC13883 to A. satureioides. For B. articulata, the major antimicrobial activity occured in winter (312 μg mL-1) against bacterial strains Bacillus cereus ATCC117, when essential oils showed be effective against bacterial strains Klebsiella pneumoniae ATCC13883 in the concentration of 78.1 μg mL-1.