Antibacterial xanthones from Kielmeyera variabilis mart. (Clusiaceae)

Abstract

The bioassay-guided fractionation of stems from Kielmeyera variabilis, traditionally used in Brazilian folk medicine, yielded assiguxanthone-B (1), kielcorin (4), 2,5-dihydroxybenzoic acid (3), and a mixture of xanthones containing assiguxanthone-B (1) and 1,3,5,6-tetrahydroxy-2-prenylxanthone (2)

Antimicrobial and cytotoxic activities of medicinal plants of the Brazilian cerrado, using Brazilian cachaça as extractor liquid

“…The best activity against bacteria was observed for the plant Kielmeyera lathrophyton, against Staphylococcus aureus (MIC = 250 g/ml) and Bacillus subtilis (MIC = 500 g/ml). Xanthones isolated from the bark of Kielmeyera variabilis showed antibacterial activity against Staphylococcus aureus and Bacillus subtilis (Pinheiro et al, 2003), while the hydroalcoholic extract of the species Kielmeyera coriacea showed anxiolytic activity (Audi et al, 2002). The CEs obtained starting from the plants Curatella americana, Sclerolobium aureum, and Plathymenia reticulata showed little or no activity against the bacteria.…”

Chemical modifications of a natural xanthone and antimicrobial activity against multidrug resistant Staphylococcus aureus and cytotoxicity against human tumor cell lines

“…Some natural xanthones are described as important anti-staphylococcal agents, including for resistant strains, having MIC values ranging from 8 until 1.95 µg/mL. 10,[33][34][35] Thus, some of the semi synthetic ω-aminoalkoxylxanthones presented herein are potential antimicrobials and can be considered relevant specially taking into account the growing problem of resistant S. aureus strains. 1 Studies have reported the synthesis and cytotoxic activity of bromoalkoxyxanthones 30 and xanthones with nitrogenated side chains 27,28 including arylhydrazones, 36 with promising results, showing IC 50 values between 2 and 30 µM.…”

Naturally Occurring Xanthones: Chemistry and Biology

“…A xanthonolignoid Kielcorin was obtained from Hypericum species [41]. Recently, kielcorin was also isolated from Vismia guaramirangae [42], Kielmeyera variabilis [43], and Hypericum canariensis [44], whereas cadensin C and cadensin D from Vismia guaramirangae and Hypericum canariensis have been reported [45].…”