Searching for Natural Bioactive Compounds in Four Baccharis species from Bolivia

Abstract

The volatile oil composition of four Baccharis species (Baccharis papilosa, B. polycephala, B. buxifolia,and B. convawyi) growing wild in Bolivia were studied by GC and GC/MS. The antimicrobial activity of the oils was determined by the agar diffusion and bioautography methods. Solvent extracts, polar and non-polar, of the same species were also tested for antimicrobial and antioxidant activities. Extracts from B. polycephala, B. papilosa and B. convawyi presented significant antioxidant activity, determined using the DPPH radical scavenging method, showing EC 50 values of 4.74, 7.17 and 7.97 μg/mL, respectively. Screening for antimicrobial activity was conducted using the agar diffusion test. The most active extracts (% inhibition ≥ 50) were further examined by the dilution method. All the plant extracts studied showed higher antimicrobial activity against S. aureus (Gram-positive) than against E. coli and P. fluorescens (Gram-negative).

Neutralizing Effects of Nectandra angustifolia Extracts against Bothrops neuwiedi Snake Venom

“…The components of the oil were analyzed as previously reported [14]; identified by comparison of their Linear Retention Indices (LRIs) on two columns, determined in relation to a homologous series of n-alkanes (C 9 to C 26 ), with those from pure standards or reported in the literature [15,16]. Comparison of fragmentation patterns in the mass spectra with those stored on the GC-MS database was also performed [17,18]. Enantiomeric ratios of -pinene, -pinene, and limonene were obtained by multidimensional GC using the experimental conditions previously described [14].…”