Table 1.

¹H (500 MHz), ¹³C (125 MHz) and 2D-NMR (500 MHz) data of 1 in CDCl₃.

Position	δH J(Hz)	δC	HMBC	COSY	NOE
2	4.51 dd (6.5, 10)	90.5	C-12, 13	H-3	H-3, 12, 13, 14
3	2.16 m	30.6	C-2,3a, 4, 7a, 11, 14	H-2	H-13
3a		60.6
4		175.1
5		107.3
6		192.3
7		106.5
7a		195.7
8(-OH)	18.84 s	198.2	C-6, 7, 8, 9
9	3.18 m	40.0	C-7, 8, 10, 1′
	3.10 m
10	2.92 m	31.0	C-8, 9, 1′, 2′, 6′
	2.85 m
1′		133.3
2′	7.19 d (8.5)	113.7	C-10, 3′, 4′, 6′
3′	6.82 d (8.5)	129.4	C-1′, 4′, 5′		OCH3-4′
4′		158.0
5′	6.82 d (8.5)	129.4	C-1′, 3′, 4′		OCH3-4′
6′	7.19 d (8.5)	113.8	C-10, 2′, 4′, 5′
11		71.2
12	1.33 s	26.6	C-2, 11, 13		H-2
13	1.16 s	23.8	C-2, 11, 12		H-2
14	2.50 dd (7.5, 14.0)	38.7	C-3a, 4, 7a, 3, 15, 16	H-15	H-2
	2.39 dd (7.5, 14.0)
15	4.96 t (7.5)	117.1	C-17, 18	H-14, 17, 18	H-17
16		137.0
17	1.66 s	25.8	C-15, 16, 18	H-15	H-15
18	1.52 s	17.8	C-15, 16, 17	H-15
19	3.10 m	21.5	C-4, 5, 6, 20, 21	H-20, 23
	3.00 dd (7.5, 14.5)
20	5.11 t (7.5)	121.5	C-19, 22, 23	H-19, 23	H-23
21		132.1
22	1.72 s	17.8	C-20, 21, 23
23	1.68 s	25.6	C-20, 21, 22	H-19, 20
4′(-OCH3)	3.77 s	55.2	C-4′		H-3′, 5′