Table 1.

Spectrum data for compound 4b.

1H NMR	1H-1HCOSY		Assignment
13.39 (bs; 1H)			OH-4/4’
12.90 (bs; 1H)			OH-4’/4
12.19 (bs; 1H)			NH-1/1’
12.08 (bs; 1H)			NH-1’/1
7.40 (d, J = 9.0; 2H)	7.26		H-8, 8’
7.40 (bs; 1H)			H-5/5’
7.33 (bs; 1H)			H-5’/5
7.26 (bd, J = 8.6; 2H)	7.40		H-7, 7’
7.02 (d, J = 8.5; 2H)	6.89		H-o
6.89 (d, J = 8.8; 2H)	7.02		H-m
6.14 (s; 1H)			H-a
4.76 (d, J = 2.0; 2H)	3.55		H-b
3.77 (s; 6H)			H-6a, 6a’
3.55 (bs; 1H)	4.76		H-d
15N NMR	HSQC	HMBC	Assignment
144.2	12.08	7.40	N-1/1’
142.9	12.19	7.40	N-1’/1
13C NMR	HSQC	HMBC	Assignment
165.76, 164.10		6.14	C-2, 2’
161.84, 160.91		6.14	C-4, 4’
155.31		7.02, 6.89, 4.76	C-p
154.80		7.40, 7.26, 3.77	C-6, 6’
131.52		7.40, 7.26	C-8a, 8a’
130.29		6.89, 6.14	C-i
127.29	7.02	7.02, 6.14	C-o
120.63	7.26		C-7, 7’
117.46	7.40	7.40	C-8, 8’
117.21, 116.70		7.40, 7.33	C-4a, 4a’
114.35	6.89	6.89, 6.89	C-m
111.74, 111.25		6.14	C-3, 3’
103.82	7.40, 7.33		C-5, 5’
79.43		4.76	C-c
78.00	3.55	3.55	C-d
55.41	3.77		C-6a, 6a’
55.34	4.76		C-b
34.69	6.14	7.02, 6.14	C-a