Flourensia cernua: Hexane Extracts a Very Active Mycobactericidal Fraction from an Inactive Leaf Decoction against Pansensitive and Panresistant Mycobacterium tuberculosis

Table 2

Yields and mycobactericidal activity of fractions obtained by liquid-liquid partition of decoction and ethanol crude extracts of Flourensia cernua.

Originating extract^a	n-Hex			EtOAc			n-BuOH
	Fraction (yield^b)	MBC^c (μg/mL)		Fraction (yield^b)	MBC^c (μg/mL)		Fraction (yield^b)	MBC^c (μg/mL)
		SMtb^d	RMtb^e		SMtb^d	RMtb^e		SMtb^d	RMtb^e
A	A1 (33.5%)	12.5	6.25	A2 (12.5%)	6.25	50	A3 (17.7%)	100	100
B	B1 (24.7%)	25	25	B2 (42.7%)	100	25	B3 (5.5%)	100	100
C	C1 (34.2%)	25	25	C2 (37.9%)	50	50	C3 (10.6%)	100	100
D	D1 (25.3%)	25	25	D2 (25.8%)	50	25	D3 (11.3%)	100	50
E	E1 (22.7%)	25	12.5	E2 (34.6%)	>100	100	E3 (6.7%)	100	100

^aDecoction (A) or crude ethanol extracts (B–E) obtained with different extraction methods (Table 1) were successively fractionated by liquid-liquid partition with n-hexane (n-Hex), ethyl acetate (EtOAc), and n-butanol (n-BuOH) and assayed for their mycobactericidal activity. ^bYield was expressed as the percentage of dry material recovered with respect to the corresponding originating extract A–E and then with respect to 15 g of ground dry leaves of F. cernua. ^cMycobactericidal activity was expressed as the minimal bactericidal activity (MBC) that killed 100% of mycobacteria. ^dSMtb M. tuberculosis H37Rv strain sensitive to all five fist-line antituberculosis drugs; ^eRMtb M. tuberculosis CIBIN/UMF15:99, resistant to the above drugs. In this experiment rifampin and ofloxacin were included as internal standards, and these showed the same MBC reported in the experiments from Table 1.