Antiproliferative Activity of Xanthones Isolated from Artocarpus obtusus

Table 1

¹H-NMR (400 MHz) and ¹³C-NMR (100 MHz) spectral data of pyranocycloartobiloxanthone B (3) and pyranocycloartobiloxanthone A (1).

H/C	(3) In acetone-𝑑6			(1) In DMSO [13]
	δ H (in ppm, J in Hz)	δ C (in ppm)	HMBC	δ H (in ppm)	δ C (in ppm)
2	—	163.1	—	—	160.7
3	—	103.6	—	—	100.8
4	—	182.3	—	—	179.1
5	—	153.8	—	—	151.2
6	6.12 (1H, s)	101.3	C-5, 7, 8	6.17	98.7
7	—	164.1	—	—	160.7
8	—	107.1	—	—	104.3
9	—	161.0	—	—	157.9
10	—	105.8	—	—	103.6
11	1.91 (1H, m)	24.2	C-3, 6′	1.88	21.5
	3.32 (1H, m)		C-3, 4, C-12	3.32
12	2.76 (1H, m)	33.9	C-13, 1′, 5′, 6′	2.55	31.2
13	2.25 (1H, dd, J = 15.6, 7.7)	38.8	C-12, 14, 6′	1.82	35.7
14	5.47 (1H, s)	96.5	C-13, 15	5.32	93.1
15	1.19 (3H, d, J = 6.4, CH3)	16.5	C-12, 13, 14	1.08	14.6
16	6.93 (1H, d, J = 10.0)	117.6	C-7, 9, 18	6.86	114.8
17	5.65 (1H, d, J = 10.0)	129.4	C-16, 18, 19	5.74	127.3
18	—	80.2	—	—	78.0
19	1.45 (3H, s, CH3)	29.8	C-17, 18	1.44	27.7
20	1.45 (3H, s, CH3)	30.0	C-17, 18	1.42	27.9
1′	—	114.3	—	—	111.0
2′	—	153.6	—	—	151.2
3′	6.49 (1H, s)	105.5	C-2′, 4′, 5′	6.43	103.1
4′	—	153.2	—	—	151.1
5′	—	135.0	—	—	132.5
6′	—	127.3	—	—	124.6
OH-5	13.37 (1H, brs)	—	C-6, 7, 10	13.36	—
OH-13	7.96 (1H, brs)	—	—	—	—
OH-14	—	—	—	6.93	—
OH-2′	8.44 (1H, brs)	—	—	9.91	—
OH-4′	8.84 (1H, brs)	—	C-3′	9.81	—