144
N. N. Win and H. Morita
(staminols A and B), two seco-staminanes (staminolactones A and B), a norstaminane (norstaminolactone), and five isopimarane-type diterpenes (orthosiphols F–J)
have also been isolated from Vietnamese O. stamineus [24–26].
Phytochemical constituents of O. stamineus native to Myanmar were first reported
in 2001 [27] and 2002 [28]. Thus, nine new highly oxygenated diterpenoids,
orthosiphols K–Q (15–21), nororthosiphonolide A (22), and norstaminone A (23)
(Fig. 6), six known diterpenoids, orthosiphols A (24) [16], B (25) [16], D (26) [15],
and E (27) [15], orthosiphonone A (28) [21] and neoorthosiphol A (29) [22] (Fig. 6),
four known flavonoids, tetramethylscutellarein (30) [29], eupatorin (31) [30], 5,6dihydroxy-7,4
-dimethoxyflavone (32) [31], and 6,7,8,3
,4
-pentamethoxyflavone
(33) [32]; and a ferulate derivative, (4-hydroxyphenyl)ethyl (E)-ferulate (34) [33]
(Fig. 7), have been shown to be constituents of O. stamineus in Myanmar. Based on
Fig. 6 Structures of
isopimarane-type diterpenes
15–22 and 24–28 and
staminane-type diterpenes 23
and 29 isolated from the
chloroform-soluble fraction
of the aerial parts of O.
stamineus
OBz
R
1
O
R
2
O
R
4
O
R
5
OAc
OH
O
OBz
AcO
R
1
O
OR
2
OH
O
O
R
3
AcO
OAc
OH
O
O
O
21 (orthosiphol Q)
O
OBz
AcO
HO
OAc
O
23 (norstaminone A)
O
OAc
OH
O
BzO
O
22 (nororthosiphonolide A)
OH
OBz
AcO
HO
BzO
OH
OAc
OH
O
29 (neoorthosiphol A)
RO
OAc
OH
O
O
26 (orthosiphol D) R = Ac
27 (orthosiphol E) R = H
BzO
15 (orthosiphol K) R
1 = R
2 = R
3 = R
5
= H, R
4 = Bz
16 (orthosiphol L) R
1 = Ac, R
2 = R
3 =H, R
4 = Bz, R
5
= OH
19 (orthosiphol O) R
1 = Ac, R
2 = Bz, R
3 = R
4 = R
5
= H
20 (orthosiphol P) R
1 = Ac, R
2 = R
5
= H, R
3 = OH, R
4 = Bz
24 (orthosiphol A) R
1 = Ac, R
2 = R
3 = R
5 = H, R
4
= Bz
25 (orthosiphol B) R
1 = R
3 = R
5 = H, R
2 = Ac, R
4 = Bz
17 (orthosiphol M) R
1 = H, R
2
= Ac
18 (orthosiphol N) R
1 = Bz, R
2 = H
28 (orthosiphonone A) R
1 = Bz, R
2 = Ac
N. N. Win and H. Morita
(staminols A and B), two seco-staminanes (staminolactones A and B), a norstaminane (norstaminolactone), and five isopimarane-type diterpenes (orthosiphols F–J)
have also been isolated from Vietnamese O. stamineus [24–26].
Phytochemical constituents of O. stamineus native to Myanmar were first reported
in 2001 [27] and 2002 [28]. Thus, nine new highly oxygenated diterpenoids,
orthosiphols K–Q (15–21), nororthosiphonolide A (22), and norstaminone A (23)
(Fig. 6), six known diterpenoids, orthosiphols A (24) [16], B (25) [16], D (26) [15],
and E (27) [15], orthosiphonone A (28) [21] and neoorthosiphol A (29) [22] (Fig. 6),
four known flavonoids, tetramethylscutellarein (30) [29], eupatorin (31) [30], 5,6dihydroxy-7,4
-dimethoxyflavone (32) [31], and 6,7,8,3
,4
-pentamethoxyflavone
(33) [32]; and a ferulate derivative, (4-hydroxyphenyl)ethyl (E)-ferulate (34) [33]
(Fig. 7), have been shown to be constituents of O. stamineus in Myanmar. Based on
Fig. 6 Structures of
isopimarane-type diterpenes
15–22 and 24–28 and
staminane-type diterpenes 23
and 29 isolated from the
chloroform-soluble fraction
of the aerial parts of O.
stamineus
OBz
R
1
O
R
2
O
R
4
O
R
5
OAc
OH
O
OBz
AcO
R
1
O
OR
2
OH
O
O
R
3
AcO
OAc
OH
O
O
O
21 (orthosiphol Q)
O
OBz
AcO
HO
OAc
O
23 (norstaminone A)
O
OAc
OH
O
BzO
O
22 (nororthosiphonolide A)
OH
OBz
AcO
HO
BzO
OH
OAc
OH
O
29 (neoorthosiphol A)
RO
OAc
OH
O
O
26 (orthosiphol D) R = Ac
27 (orthosiphol E) R = H
BzO
15 (orthosiphol K) R
1 = R
2 = R
3 = R
5
= H, R
4 = Bz
16 (orthosiphol L) R
1 = Ac, R
2 = R
3 =H, R
4 = Bz, R
5
= OH
19 (orthosiphol O) R
1 = Ac, R
2 = Bz, R
3 = R
4 = R
5
= H
20 (orthosiphol P) R
1 = Ac, R
2 = R
5
= H, R
3 = OH, R
4 = Bz
24 (orthosiphol A) R
1 = Ac, R
2 = R
3 = R
5 = H, R
4
= Bz
25 (orthosiphol B) R
1 = R
3 = R
5 = H, R
2 = Ac, R
4 = Bz
17 (orthosiphol M) R
1 = H, R
2
= Ac
18 (orthosiphol N) R
1 = Bz, R
2 = H
28 (orthosiphonone A) R
1 = Bz, R
2 = Ac