Tyrosinase Inhibitors from the Stems of Streblus Ilicifolius

Table 1

¹H (500 MHz) and ¹³C (125 MHz) NMR data (acetone-d₆) for compounds 1 and 2.

Position	1		2
	δC, type C	δH (J, Hz)	δC, type C	δH (J, Hz)
1	116.3, C		122.0, C
2	158.3, C		158.0, C
3	103.6, CH	6.46, d (2.4)	98.3, CH	7.00, d (2.1)
4	160.8, C		158.9, C
5	108.9, CH	6.42, dd (8.5, 2.4)	114.3, CH	6.87, dd (8.5, 2.1)
6	129.6, CH	7.48, d (8.5)	123.4, CH	7.52, d (8.5)
1′	153.9, C		143.6, C
2′	125.0, CH	5.97, d (2.0)	118.7, CH	6.48, d (2.1)
3′	199.2, C=O		200.6, C=O
4′	82.8, C		79.6, C
5′	77.3, CH	4.48, dd (4.3, 1.6)	73.0, CH	4.27, dd (5.9, 2.7)
6′	27.4, CH2	3.19, dd (18.8, 1.6); 2.82, ddd (18.8, 4.3, 2.0)	32.0, CH2	3.15, ddd (18.5, 5.9, 2.1); 3.08, dd (18.5, 2.7)
α	132.3, CH	7.40, d (16.4)	110.7, CH	7.31, s
β	126.4, CH	7.01, d (16.4)	153.2, C
1″	33.0, CH2	2.54, dd (14.4, 8.0); 2.39, dd (14.4, 7.2)	35.3, CH2	2.47, dd (14.9, 7.7); 2.40, dd (14.9, 7.0)
2″	118.1, CH	5.18, brs	118.8, CH	5.22, brt (7.3)
3″	136.0, C		135.0, C
4″	26.0, CH3	1.68, s	26.1, CH3	1.67, s
5″	18.1, CH3	1.63, s	18.1, CH3	1.58, s
1‴	108.0, C
2‴	27.8, CH3	1.32, s
3‴	26.8, CH3	1.18, s
4-OH				8.88, s
4′-OH				4.18, s
5′-OH				3.83, s