Table 1.

¹H and ¹³C-NMR data for compound 1 (400 and 100 MHz, in DMSO, ppm, J/Hz).

Positon	δH	δC	HMBC
1	7.21 d (10.1)	156.9	C-3, C-5, C-9, C-10, C-19
2	6.11 dd (10.1, 1.9)	127.1	C-10
3	–	185.3
4	6.00 s	123.3	C-6, C-10
5	–	170.1
6	2.48 m2.33 m	32.4	C-5
7	2.27 m0.98 m	32.7
8	1.94 m	31.7
9	1.05 m	53.1	C-19
10	–	43.8
11	1.68 m1.61 m	22.3
12	1.57 m1.01 m	38.3	C-18
13	–	43.3
14	0.78 dd (11.1, 5.8)	59.0	C-8, C-13, C-18
15	4.10 m	69.0
16	2.18 m ( α )	39.7	C-13
	1.51 m ( β )
17	1.85 m	55.0
18	0.87 s	15.7	C-12, C-13, C-14, C-17
19	1.22 s	18.9	C-1, C-5, C-9, C-10
20	5.79 ddd(17.3, 10.4, 7.4)	139.6
21	4.98 dd (10.4, 1.7)	115.3	C-17
	4.96 dd (17.3, 1.7)
15-OH	4.45 d (4.0)