Antibacterial and antifungal properties of wax and hexane extracts of
Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (
Penicillium digitatum
,
Curvularia sp., and Colletotrichum sp.), two human pathogens (
Trichophyton mentagrophytes
and
Microsporum canis
), and two opportunistic bacteria (
Escherichia coli
and
Staphylococcus aureus
). Two polymethoxylated flavonoids and a coumarin derivative, were isolated and identified from peel extracts, which presented antimicrobial activity especially against
M. canis and
T. mentagrophytes: 4',5,6,7,8-pentamethoxyflavone (tangeritin) and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin) from
C. reticulata; and 6,7-dimethoxycoumarin (also known as escoparone, scoparone or scoparin) from
C. limon.