202
N. N. Win and H. Morita
OH
363 (12β-hydroxy-15-norlabda8(17),13(14)-dien-16-oic acid)
364 ((E)-15-ethoxy-15-methoxylabda8(17),12-dien-16-al)
366 (15-ethoxy-12β-hydroxylabda8(17),13(14)-dien-16,15-olide)
O
HO
365 ((E)-15α-ethoxy-14α-hydroxylabda8(17),12-dien-16-olide)
O
HO
O
O
O
O
O
OH
O
O
O
Fig. 71 Structures of the new labdane diterpenoids 363–366 isolated from a methanol extract of
C. amada rhizomes grown in Myanmar
[426]), antioxidant, cytotoxic, antimicrobial, platelet aggregation inhibitory [427],
anti-inflammatory, antiallergic, biopesticide, and hyperglyceridemia effects, have
been described previously [428].
Phytochemical and pharmacological studies of C. amada native to Myanmar
were reported in 2017 [429]. Disernible antiproliferative activities were displayed
by a MeOH extract of C. amada rhizomes, with IC 50 values ranging from 31.7 to
49.2 μg/cm
3 , against the A549 (human lung cancer), HeLa (human cervix cancer),
MCF7 (human breast cancer), and PANC-1 and PSN-1 (human pancreatic cancer)
cell lines. Furthermore, phytochemical workup of this bioactive methanol extract
resulted in the isolation of 17 compounds, including four new labdane diterpenoids
(12β-hydroxy-15-norlabda-8(17),13(14)-dien-16-oic acid (363), (E)-15-ethoxy15-methoxylabda-8(17),12-dien-16-al (364), (E)-15α-ethoxy-14α-hydroxylabda8(17),12-dien-16-olide (365), and 15-ethoxy-12β-hydroxylabda-8(17),13(14)-dien16,15-olide (366) [429]) (Fig. 71), together with the 13 known labdane diterpenoids ((E)-15,16-bisnorlabda-8(17),11-dien-13-one (367) [409], (E)-14,15,16trinorlabda-8(17),11-dien-13-al (368) [418], (E)-14,15,16-trinorlabda-8(17),11dien-13-oic acid (369) [423], 16-oxolabda-8(17),12-dien-15,11-olide (370) [419],
(E)-15,15-diethoxylabda-8(17),12-dien-16-al (371) [425], (E)-labda-8(17),12-dien15,16-dial (372) [430], (E)-14-hydroxy-15-norlabda-8(17),12-dien-16-al (373)
[423], zarumin A (374) [412], methyl (12E)-16-oxolabda-8(17),12-dien-15-oate
(375) [417], (E)-labda-8(17),12-dien-15-ol-16-al (376) [421] coronarin D ethyl ether
N. N. Win and H. Morita
OH
363 (12β-hydroxy-15-norlabda8(17),13(14)-dien-16-oic acid)
364 ((E)-15-ethoxy-15-methoxylabda8(17),12-dien-16-al)
366 (15-ethoxy-12β-hydroxylabda8(17),13(14)-dien-16,15-olide)
O
HO
365 ((E)-15α-ethoxy-14α-hydroxylabda8(17),12-dien-16-olide)
O
HO
O
O
O
O
O
OH
O
O
O
Fig. 71 Structures of the new labdane diterpenoids 363–366 isolated from a methanol extract of
C. amada rhizomes grown in Myanmar
[426]), antioxidant, cytotoxic, antimicrobial, platelet aggregation inhibitory [427],
anti-inflammatory, antiallergic, biopesticide, and hyperglyceridemia effects, have
been described previously [428].
Phytochemical and pharmacological studies of C. amada native to Myanmar
were reported in 2017 [429]. Disernible antiproliferative activities were displayed
by a MeOH extract of C. amada rhizomes, with IC 50 values ranging from 31.7 to
49.2 μg/cm
3 , against the A549 (human lung cancer), HeLa (human cervix cancer),
MCF7 (human breast cancer), and PANC-1 and PSN-1 (human pancreatic cancer)
cell lines. Furthermore, phytochemical workup of this bioactive methanol extract
resulted in the isolation of 17 compounds, including four new labdane diterpenoids
(12β-hydroxy-15-norlabda-8(17),13(14)-dien-16-oic acid (363), (E)-15-ethoxy15-methoxylabda-8(17),12-dien-16-al (364), (E)-15α-ethoxy-14α-hydroxylabda8(17),12-dien-16-olide (365), and 15-ethoxy-12β-hydroxylabda-8(17),13(14)-dien16,15-olide (366) [429]) (Fig. 71), together with the 13 known labdane diterpenoids ((E)-15,16-bisnorlabda-8(17),11-dien-13-one (367) [409], (E)-14,15,16trinorlabda-8(17),11-dien-13-al (368) [418], (E)-14,15,16-trinorlabda-8(17),11dien-13-oic acid (369) [423], 16-oxolabda-8(17),12-dien-15,11-olide (370) [419],
(E)-15,15-diethoxylabda-8(17),12-dien-16-al (371) [425], (E)-labda-8(17),12-dien15,16-dial (372) [430], (E)-14-hydroxy-15-norlabda-8(17),12-dien-16-al (373)
[423], zarumin A (374) [412], methyl (12E)-16-oxolabda-8(17),12-dien-15-oate
(375) [417], (E)-labda-8(17),12-dien-15-ol-16-al (376) [421] coronarin D ethyl ether