O
R 1 OH
HO
R 2
OH
O
HN
O OH
OH
(32)R 1 : OH, R 2 : H
(33)R 1 : H, R 2 : OH
N
H O
O
O
H
H
H
(34)
N
O
OH
O
H
H
H
(35)
N
H
OH
H
H
OH
(36)
O O
O
OH O O
O H H
O
O
O
(37)
O
O OH
OH
O
OH
(38)
OH
R
(39)R=H 2
(40)R=O
O
OH
(41)
N
O
O
R
H
(42)R=OH
(43) R=H
N
H
OH
O
H
OH
(44)
204 P.B. Ratnaweera and E.D. de Silva