TABLE 3.

NMR data for X5-Me and X6-Me^a

No.	X5-Me			X6-Me
	13C-NMR (δ [ppm])	1H-NMR (δ [ppm]), J (Hz)b	HMBC	13C-NMR (δ [ppm])	1H-NMR (δ [ppm]), J (Hz)b
1	130.3	7.47 dq (11.5, 0.9)	C3, C5, C19	138.3	7.55 d (7.8)
2	119.0	6.95 d (11.5)	C3, C4, C10	123.0	7.89 d (7.8)
3	149.4			145.0
4	163.6			166.1
5	202.2			160.7
6	35.4	3.01 ddd (17.5, 6.9, 6.9)	C5, C7, C8	33.2	3.10 ddd (14.2, 8.8, 6.4)
		2.82 ddd (17.5, 7.3, 7.3)	C5, C7, C8		2.84 ddd (14.2, 9.3, 7.3)
7	21.3	1.85 m	C5	24.8	1.93 m
8	49.2	2.55 m		49.4	2.69 ddd (11.7, 7.3, 3.9)
9	211.5			211.2
10	139.8			136.0
11	37.5	2.50 m	C9, C12, C13	37.5	2.50 ddd (15.6, 13.2, 6.4)
		2.44 m	C9, C12, C13		2.42 ddd (15.6, 6.4, 2.4)
12	30.4	2.01 ddd (13.3, 6.0, 2.3)		30.6	2.00 ddd (13.2, 6.4, 2.4)
		1.68 ddd (13.3, 12.8, 6.4)	C18		1.68 ddd (13.2, 13.2, 6.4)
13	47.6			47.6
14	49.6	1.84 m		49.6	1.89 m
15	22.2	2.10 m	C17	22.3	2.10 m
		1.85 m			1.85 m
16	36.1	2.59 dd (19.3, 7.8)	C17	36.2	2.58 dd (19.1, 8.3)
		2.24 ddd (19.3, 9.2, 9.2)	C17		2.23 ddd (19.1, 9.3, 8.8)
17	218.7			218.2
18	13.5	1.18 s	C12, C13, C14, C17	13.5	1.17 s
19	12.2	1.95 d (0.9)	C1, C5, C10	19.0	2.47 s
3-OMe	60.8	3.86 s	C3
COOMe	52.4	3.85 s	C4	52.6	3.97 s

^aThe molecular formula and weight of X5-Me and X6-Me are C₁₂H₂₈O₆ and 376 and C₂₀H₂₅NO₄ and 343, respectively. In HMBC data, carbons showing cross peaks with the proton are in the same row.

^bAbbreviations for NMR: s, singlet; d, doublet; q, quartet, m, multiplet.