Bacterial resistance modifying tetrasaccharides from the flowers of Ipomoea murucoides Roemer & Schultes

Five new resin glycosides from the murucoidin series (XIV-XVIII) were isolated from the flowers of an arborescent medicinal morning-glory species, Ipomoea murucoides Roemer & Schultes. They were tested for in vitro antibacterial and resistance modifying activity againts strains of Staphylococcus aureus posseing Nor(A) multidrug resistance efflux mechanisms. At 512µg/mL none of them displayed activity but individually in combination with norfloxacin, a two-fold activity potentiation of the control antibiotic was observed.

	R1	R2	R3	R4	R5
Mur XIV	dodeca	OH	OH	H	CH2OH		R1	R2
Mur XV	OH	Dodeca	OH	H	CH2OH	Mur XVII	mba	OH
Mur XVI	Dodeca	OH	H	OH	CH3	Mur XVIII	OH	mba
Mur=murucoidin; dodeca=n-dodecanoyl; mba=(2S)-methylbutanoyl

Acknowledgements. Consejo Nacional de Ciencia y Tecnología (45861-Q) and DGAPA, UNAM (IN208307).