Table 5. NMR Spectroscopic Data (¹H at 800 MHz, ¹³C at 200 MHz, CD₃OD) of 2,3-Dehydro-3″-hydroxychamanetin (5).

position	δC, type	δH	J (Hz)	HMBC, H→C
2	165.8, C–O
3	105.6, CH	6.69	s	C-2, C-4, C-4a, C-1′
4	184.3, C=O
4a	105.7, C
5	161.2, C–O
6	99.9, CH	6.36	s	C-4, C-4a, C-5, C-7, C-8
7	164.3, C–O
8	107.4, C
8a	157.0, C–O
1′	132.6, C
2′/6′	127.6, CH	7.80	m	C-2, C-2′/6′, C-4′
3′/5′	130.2, CH	7.47	m	C-1′, C-2′/6′, C-3′/5′
4′	132.9, CH	7.51	m	C-2′/6′
1″	128.3, C
2″	144.2, C–O
3″	146.0, C–O
4″	113.9, CH	6.62	dd, (7.8, 1.6)	C-2″, C-3″, C-5″ C-6″
5″	120.3, CH	6.47	dd, (7.9, 7.8)	C-1″, C-3″, C-4″, C-6″
6″	120.4, CH	6.34	dd, (7.9, 1.6)	C-2″, C-4″, C-7″
7″	22.8, CH2	4.16	s	C-7, C-8, C-8a, C-1″, C-2″, C-6″