Table 1.

¹³C (100 MHz) and ¹H (500 MHz) NMR Data of Compounds 1–4^a

position	AT2433-A3 (1)b,c		AT2433-A4 (2)b,d		AT2433-A5 (3)b,d		AT2433-B3 (4)b,c
	δC, type	δH, m (J in Hz)	δC, type	δH, m (J in Hz)	δC, type	δH, m, (J in Hz)	δC, type	δH, m (J in Hz)
1	112.7, CH	7.72, d (8.0)	112.2, CH	7.75, d (8.0)	112.2, CH	7.82, dd (8.0, 1.0)	113.1, CH	7.69, d (7.5)
2	129.2, CH	7.64, t (7.0)	127.6, CH	7.61, td (7.5, 1.5)	127.1, CH	7.56, td (8.0, 1.0)	128.0, CH	7.53, td (8.0, 1.0)
3	122.4, CH	7.32, t (7.0)	120.7, CH	7.40, t (7.0)	121.3, CH	7.36, td (8.0, 1.0)	121.6, CH	7.32, td (8.0, 1.0)
4	126.8, CH	8.99, d (8.0)	124.5, CH	9.12, d (8.0)	124.2, CH	8.95, d (8.0)	126.2, CH	9.13, d (8.0)
4a	121.4, C		121.0, C		119.8, C		123.5, C*
4b	119.8, C		117.5, C		115.9, C		119.6, C*
4c	124.4, C		118.2, C		118.9, C		119.7, C
5	172.2, C		169.3, C		169.7, C		171.3, C*
6-CH3			23.9, CH3	3.20, s	23.6, CH3	3.11, s	24.0, CH3	3.24, s
7	172.2, C		169.5, C		169.7, C		171.3, C*
7a	123.4, C		121.9, C		120.5, C		119.7, C
7b	121.4, C		119.4, C		115.5, C		119.6, C
7c	127.5, C		125.5, C		123.1, C		123.5, C*
8	125.9, CH	9.20, d (8.0)	123.8, CH	9.27, dd (8.0, 1.0)	123.3, CH	8.87, d (8.0)	126.4, CH	9.23, d (8.0)
9	123.8, CH	7.30, t (8.0)	122.5, CH	7.42, t (8.0)	121.3, CH	7.34, t (7.5)	122.0, CH	7.34, t (8.0)
10	131.0, CH	7.52, d (7.5)	129.6, CH	7.65, dd (7.5, 1.0)	126.0, CH	7.62, dd (7.5, 1.0)	128.3, CH	7.56, td (8.5, 1.5)
11	118.1, C		116.5, C		115.8, C		112.1, CH	7.81, d (8.5)
11a	139.9, C		138.2, C		137.1, C		142.9, C
12						11.95, brs
12a	131.8, C		129.7, C		128.8, C		130.8, C
12b	131.4, C		130.3, C		129.0, C		131.6, C
13				11.81, brs		11.64, brs
13a	141.9, C		140.8, C		140.1, C		141.9, C
1′	86.5, CH	7.01, d (9.5)	83.8, CH	6.90, d (9.0)			86.3, CH	6.18, d (8.5)
2′	73.8, CH	3.82, m	72.1, CH	3.41, m			73.7, CH	3.84, t (8.0)
2′-OH				4.94, d (5.5)
3′	79.5, CH	3.68, m	76.6, CH	3.51, m			79.1, CH	3.98, t (9.5)
3′-OH				5.28, d (6.5)
4′	80.3, CH	3.68, m	77.0, CH	3.67, t (9.5)			79.6, CH	3.85, t (9.5)
4′-OCH3	61.5, CH3	3.74, s	60.1, CH3	3.61, s			61.4, CH3	3.80, s
5′	79.5, CH	4.06, m	77.6, CH	3.90, d (10.0)			75.0, CH	4.06, m
6′	67.5, CH2	4.41, d (10.0) 4.08, m	58.7, CH2	4.00, brd (2.0)			60.4, CH2	4.12, d (11.5) 4.08, dd (11.5, 2.0)
6′-OH				6.34, t (4.0)
1″	100.4, CH	5.28, brs
2″	38.7, CH2	2.54, m 2.03, m
3″	65.4, CH	4.02, m
4″	61.5, CH	3.05, m
4″-NHCH3	31.6, CH3	2.51, s
5″	59.0, CH2	4.04, m 3.84, m

^aAssignments supported by 2D HSQC and HMBC experiments.

^bSee Supporting Information for the NMR spectra.

^cCD₃OD.

^dDMSO-d₆.

^*Obtained from the HMBC spectrum.