Antitubercular evaluation of root extract and isolated phytochemicals from Lophira lanceolata against two resistant strains of Mycobacterium tuberculosis

Figures & data

Table 1. ¹H and ¹³C NMR spectroscopic data^a of compounds 1a and 1b (500 and 125 MHz in DMSO-d₆) δ in ppm, with those of reference (compound 8^c).

	1a		1b		8^c
No.	δC	δH	δC	δH	δC	δH
1	71.4	3.79 (1H, –^b) 3.39 (1H, –^b)	155.6	8.06 (1H, s)	156.4	8.27 (1H, s)
2	49.4	2.76 (1H, m, J = 3.3, 6.9, 10.9)	125.4	–	122.1	–
3	190.6	–	174.5	–	175.4	–
4	115.8	–	115.7	–	117.1	–
5	128.9	7.60 (1H, d, J = 8.5)	128.9	7.60 (1H, d, J = 8.5)	128.2	7.91 (1H, d)
6	115.7	6.75 (1H, dd, J = 8.5; 2.3)	115.7	6.75 (1H, dd, J = 8.5; 2.3)	115.9	6.89 (1H, dd)
7	165.0	–	165.1	–	163.4	–
8	102.8	6.28 (1H, d, J = 2.3)	102.8	6.28 (1H, d, J = 2.3)	103.1	6.75 (1H, d)
9	159.0	–	159.0	–	158.5	–
10	49.1	4.04 (1H, dd, J = 12.4; 10.6)	50.7	4.98 (1H, –^b)	43.9	6.12 (1H, d)
11	205.4	–	203.0	–	202.9	–
12	114.3	–	114.3	–	114.1	–
13	165.1	–	165.1		166.8	–
14	102.6	6.18 (1H, d, J = 2.3)	102.7	6.18 (1H, d, J = 2.3)	103.3	6.18 (1H, d)
15	165.6	–	165.6	–	166.8	–
16	108.7	6.48 (1H, dd, J = 8.5; 2.3)	108.7	6.48 (1H, dd, J = 8.5; 2.3)	109.0	6.42(1H, d)
17	132.9	7.39 (1H, d, J = 8.5)	132.9	7.39 (1H, d, J = 8.5)	134.4	8.32 (1H, d)
18	55.3	3.75 (1H, d, J = 12.4)	56.3	3.80 (1H, –^b)	53.4	4.47 (1H, d)
19	132.9	–	133.2	–	135.6	–
20	130.6	7.28 (2H, d, J = 8.3)	130.6	7.28 (2H, d, J = 8.3)	129.4	7.24 (2H, d)
21	115.2	6.73 (2H, d, J = 8.3)	115.2	6.73 (2H, d, J = 8.3)	115.9	6.63 (2H, d)
22	156.0	–	156.0	–	156.5	–
23	115.2	6.73 (2H, d, J = 8.3)	115.2	6.73 (2H, d, J = 8.3)	115.9	6.63 (2H, d)
24	130.6	7.28 (2H, d, J = 8.3)	130.6	7.28 (2H, d, J = 8.3)	129.4	7.24 (2H, d)
25	133.1	–	133.1	–	134.5	–
26	129.5	7.29 (2H, d, J = 8.5)	129.5	7.29 (2H, d, J = 8.5)	130.0	7.23 (2H, d)
27	115.4	6.52 (2H, d, J = 8.5)	115.4	6.52 (2H, d, J = 8.5)	115.8	6.59 (2H, d)
28	157.6	–	157.6	–	156.4	–
29	115.4	6.52 (2H, d, J = 8.5)	115.4	6.52 (2H, d, J = 8.5)	115.8	6.59 (2H, d)
30	129.5	7.29 (2H, d, J = 8.5)	129.5	7.29 (2H, d, J = 8.5)	130.0	7.23 (2H, d)

^aAssignments were confirmed by DEPT-135, HSQC, HMBC, ¹H–¹H COSY and NOESY experiments.

^bOverlapping signals.

^cSpectroscopic data recorded in acetone-d₆.

Table 2. MIC and MBC values of the methanol extract and the isolated compounds against Mycobacterium tuberculosis (AC45).

Plant species/compounds	MIC^a (µg/mL)	MBC^b (µg/mL)	MBC/MIC
L. lanceolata	312.5	625	2
Mixture of 1a and 1b	31.25	125	4
2	15.75	62.5	4
4	62.5	250	4
5	62.5	125	2
Mixture of 6a, 6b and 6c	250	250	1
7	62.5	125	2
8^c	62.5	125	2
RMP	0.976	7.8125	8

RMP: rifampicin.

^aMinimum inhibitory concentration.

^bMinimum bactericidal concentration.

^cCompound 8 (authentic sample available in our laboratory).

Table 3. MIC and MBC values of the methanol extract and the isolated compounds against Mycobacterium tuberculosis (AC83).

Plant species/compounds	MIC^a (µg/mL)	MBC^b (µg/mL)	MBC/MIC
L. lanceolata	1250	2500	2
Mixture of 1a and 1b	62.5	125	2
2	62.5	125	2
4	125	250	2
5	nd^d	–	–
Mixture of 6a, 6b and 6c	250	–	–
7	125	250	2
8^c	125	–	–
INH	3.904	15.625	4

INH: isoniazid.

^aMinimum inhibitory concentration.

^bMinimum bactericidal concentration.

^cCompound 8 (authentic sample available in our laboratory).

^dNot determined: nd (CMI >250 µg/mL).

Figure 1. Constituents isolated from Lophira lanceolata.

Figure 2. Selected HMBC

NOESY

and COSY

correlations for compound 1a.