¹³C NMR data (100 MHz) of compounds 1–4 and 11^a.

Position	1b	2b	2b	4c	11d
1	111.2	119.7	121.2	111.5	114.8
2	144.0	138.0	149.3	150.0	147.3
3	145.2	149.2	138.1	147.1	144.6
4	110.6	112.3	122.6	118.6	111.7
4a	125.5	130.0	127.1	129.2	124.7
5	28.7	29.4	28.6	29.7	28.5
6	51.3	51.2	51.1	53.1	51.1
8	53.5	53.7	53.8	55.3	53.5
8a	128.4	129.2	129.3	128.5	125.7
9	147.7	147.7	147.7	145.5	143.2
10	141.0	141.0	141.0	149.3	146.0
11	121.4	121.2	124.2	116.8	112.3
12	124.3	124.2	124.2	125.9	123.7
12a	133.4	133.7	135.9	127.6	128.3
13	36.0	36.4	36.4	37.0	35.8
13a	58.8	58.6	59.1	61.4	58.6
13b	130.3	133.1	133.6	133.4	129.9
2-OCH3			56.0	57.5
3-OCH3	55.9	55.8
9-OCH3	60.6	60.6	60.6	60.9	59.2
10-OCH3					55.5
		20.8
		169.3
			20.8
			169.2
	20.8	20.6	20.6
	169.1	169.2	169.2
1′				103.3
2′				75.4
3′				78.3
4′				71.9
5′				78.7
6′				63.0

^aAssignments were based on ¹H–¹H COSY, HMQC, HMBC, and NOESY experiments; chemical shifts (δ) are given in ppm.

^bRecorded in CDCl₃.

^cRecorded in CD₃OD.

^dRecorded in DMSO-d₆.