Isolation, characterization, and anthelminthic activities of a novel dichapetalin and other constituents of Dichapetalum filicaule

Figures & data

Table 1. ¹H and ¹³C NMR data of dichapetalin X (1).

C/H	HSQC/DEPT	δH	HMBC	^1H–^1H COSY	NOESY
1	40.1 (CH2)	1.69 ^a; 2.11, dd, J = 16.2, 7.1	C-2, 3, 5, 10, 19	H-1, 2	H-19
2	117.8 (CH)	5.41, ddd, J = 7.1, 1.8, 1.8	C-1, 4, 10	H-1	H-5′, 1, 19
3	140.0 (C)	–	–	–	–
4	38.3 (C)	–	–	–	–
5	43.8 (CH2)	2.01 ^a	C-4, 7, 19, 28	H-6, 28	H-18
6	24.2 (CH2)	1.65, ddd, J = 13.8, 13.8, 2.4 1.86, ddd, J = 13.8, 3.0, 3.0	C-4, 7	H-5, 6, 7	H-6, 18, 19, 28
7	72.3 (CH)	3.95, dd, J = 3.0, 2.4	C-5, 18	H-6	H-6, 9, 18
8	36.4 (C)	–	–	–	–
9	45.7 (CH)	2.00 ^a	–	H-12	H-6, 28
10	36.2	–	–	–	–
11	124.0 (CH)	5.46, dd, J = 10.2, 2.6	C-13, 14	H-9, 12	H-1, 18, 19
12	129.1 (CH)	6.19, dd, J = 10.2, 3.1	C-9, 13, 14	H-9, 11	H-11, 17, 20, 30
13	29.9 (C)	–	–	–	–
14	35.7 (C)	–	–	–	–
15	24.8 (CH2)	2.05, m	–	H-30	–
16	23.3 (CH2)	1.76, ddd, J = 15.6, 19.2, 9.6	C-13, 14	H-17, 30	H-30
17	40.3 (CH)	2.64 ^a	C-13, 20, 22, 30	H-16, 20, 30	H-5′, 16, 20, 30
18	17.5 (CH3)	0.92, s	C-7, 9, 14	–	–
19	18.2 (CH3)	1.09, s	C-2′, 1, 5, 9, 10	–	–
20	47.0 (CH)	3.03, dd, J = 10.0, 5.1	C-13, 16, 17, 21	H-17, 22	H-17, 2′″
21	173.9 (C)	–	–	–
22	72.1 (CH)	4.19, d, J = 9.5	–	H-17, 20	H-17, 20, 24, 30
23	111.4 (C)	–	–	–	–
24	45.8 (CH2)	2.51, d, J = 15.2, 2.88, d, J = 15.2	C-22, 23, 25, 26, 27	H-24	H-24
25	86.0 (C)	–	–	–	–
26	78.3 (CH2)	4.07, d, J = 10.2 4.37, d, J = 10.2	C-23, 24, 25, 27	H-24, 26	H-26, 27
27	21.6 (CH3)	1.71, s	C-24, 25, 26	–	–
28	23.8 (CH3)	1.33, s	C-2′, 3, 4, 5	–	–
30	15.5 (CH2)	0.93, d, J = 5.3 1.28 ^a	C-12, 13, 16, 17	H-15, 16, 17, 30	–
2′	72.5 (CH2)	3.61, d, J = 10.5 3.78, d, J = 10.5	C-6′, 3, 4, 28	H-2′, 28	H-1, 2′, 6, 19, 28
5′	40.7 (CH2)	2.21,dd, J = 13.7, 2.7	C-2, 3, 4	H-6′	–
1′′	142.6 (C)	–	–	–	–
2′′, 6′′	125.8 (CH)	7.34, m	C-1′′, 4′′	H-3′′, 4′′, 5′′	H-5′, 6′, 17, 28
3′′, 5′′	128.4 (CH)	7.38, m	C-4′′, 6′′	H-2′′, 4′′, 6′′	H-5′, 6′, 17, 28
4′′	127.5 (CH)	7.27, m	C-2′′, 6′′	H-2′′, 6′′, H-3′′, 5′′	–
1′′′	172.1 (C)	–	–	–	–
2′′′	43.7 (CH2)	2.40, dd, J = 16.2, 9.2 2.46, dd, J = 16.2, 3.6	C-1′′′, 3′′′, 4′′′	H-2′′′, 3′′′	H-20, 30
3′′′	64.6 (CH)	4.20 ^a	–	H-2′′′, 4′′′	H-2′′′, 4′′′
4′′′	22.7 (CH3)	1.23, d, J = 6.1	C-1′′′, 2′′′, 3′′′	H-3′′′	–

^aOverlapping signals.

Table 2. Some ¹³C and ¹H NMR (in C₅D₅N) signals of pomolic acid (3).

Carbon no.	δc/ppm	δH/ppm
2	28.2	2.49 (2H, td, J1 = 15 Hz, J2 = 6 Hz) –CH(OH)CH2CH2–
3	78.2	3.20 (1H, m) –CH2CH(OH)C–
12	128.1	5.35 (1H, t, J = 6 Hz) –CH2CH = C–
13	137.9	–
18	54.7	2.55 (1H, s) –C = CHCCO–
19	72.7	–
23	28.8	0.92 (3H, s) CH3C–
24	16.8	0.86 (3H, s) CH3C–
25	15.6	0.95 (3H, d, J = 7.8 Hz) CH3C–CH–
26	17.3	0.78 (3H, d, J = 6 Hz) CH3C–CH–
27	24.7	1.22 (3H, s) CH3C–
28	180.7	–
29	27.2	0.99 (3H, s) CH3C(OH) –
30	16.5	3H, d, J = 9 Hz) CH3CH–

Table 3. ¹³C and ¹H NMR data of glycerol monostearate (4).

Carbon number	δC, ppm	δH, ppm
1	174.34	–	–C = O
2	34.16	2.35 (2H, t, J = 7 Hz)	–CH2–CH2–CO
3	24.91	1.63 (2H, quintet, J = 7 Hz)	–CH2–CH2–CH2CO
4–17	22.68,29.12–29.68, 31.91	1.23–1.35 (28H, m)	– (CH2)14–
18	14.10	0.80 (3H, t, J = 7 Hz)	CH3–CH2–
1′	65.00	4.14 (1H, dd, J1 = 5 Hz, J2 = 12 Hz)	COO–CH2–CH(OH) –
		4.11 (1H, dd, J1 = 12 Hz, J2 = 5 Hz)
2′	70.00	3.88 (1H, quintet, J = 5 Hz)	–O–CH2–CH(OH) –CH2(OH)
3′	63.00	3.64 (1H, dd, J1 = 5 Hz, J2 = 12 Hz)	–CH(OH) –CH2(OH)
		3.56 1H, dd, J1 = 5 Hz, J2 = 12 Hz)

Figure 1. Structures of dichapetalins X (1) and A (2).

Figure 2. Some fragmentations observed in dichapetalin X (1).

Figure 3. Structure of dichapetalin M.

Figure 4. (a) Some HMBC interactions observed in 1. (b) Some NOEs observed in 1.

Figure 5. Structures of pomolic acid (3) and glycerol monostearate (4).

Table 4. In vitro average % EHI values at different concentrations of extracts, pure compounds, and albendazole.

Mean % EHI
Concentration, µg/ml	PE	CA	M
Extracts
5000	100 ± 0.0	100 ± 0.0	100 ± 0.0
2500	100 ± 0.0	98.7 ± 1.3	100 ± 0.0
1250	96.8 ± 3.3	71.8 ± 28.0	56.3 ± 43.8
625	17.6 ± 14.0	20.5 ± 14.6	23.8 ± 9.5
312.5	15.2 ± 15.0	5.1 ± 0.8	13.0 ± 4.7
156.25	9.2 ± 4.4	11.9 ± 11.9	8.5 ± 8.5
78.125	11.9 ± 7.7	8.7 ± 5.6	12.5 ± 7.5
	Glycerol monostearate (4)	Dichapetalin X(1)	Dichapetalin A (2)
Pure compounds
2000	100 ± 0.0	100 ± 0.0	–
1000	100 ± 0.0	100 ± 0.0	100 ± 0.0
500	91.1 ± 0.1	48.8 ± 32.8	100 ± 0.0
250	28.3 ± 15.0	11.9 ± 3.1	90.2 ± 6.8
125	1.4 ± 1.4	12.0 ± 8.6	23.4 ± 4.8
62.5	–	6.6 ± 6.6	3.7 ± 3.7
31.25	1.7 ± 1.7	9.1 ± 9.1	3.5 ± 3.5
15.625	–	–	1.9 ± 1.9
Albendazole
2500	100 ± 0.0
1250	99.0 ± 1.0
650	92.6 ± 2.5
312.5	90.8 ± 1.8
156.25	92.9 ± 0.0
78.125	72.5 ± 2.5
39.0625	62.5 ± 2.5

Data are mean ± SEM. PE, petroleum ether extract; CA, chloroform–acetone extract; M, methanol extract.

Table 5. IC₅₀ values (± SEM) for extracts (M, CA, and PE), pure compounds (Dichapetalin X, Dichapetalin A and Glycerol monostearate), and albendazole.

Sample	IC50 ± SEM
Extracts
M	1236 ± 0.10
CA	1023 ± 0.07
PE	856.0 ± 0.08
Pure compounds
Dichapetalin X (1)	523.2 ± 0.06
Dichapetalin A (2)	162.4 ± 0.02
Glycerol monostearate (4)	306 ± 0.03
Albendazole
	93.27 ± 0.05

PE, petroleum ether extract; CA, chloroform–acetone extract; M, methanol extract.

Figure 6. PCR identification of hookworm species. Lane M is the molecular weight marker, lanes 1–5 are genomic DNA of N. americanus eggs, lane 7 is the N. americanus positive control corresponding to 870 base pairs, lanes 6 and 8 are the two negative controls for the two species and lane 9 is the A. duodenale, positive control corresponding to 690 base pairs.