university of kwazulu-natal faculty of science and agriculture school ...

In compounds 149-165 (Table 9b), an olefinic bond is present at C-5 while oxygenated
substituents occur at C-11, C-12 and C-14. With the exception of compound 157,
compounds 153-165 have either one or both of the isopropyl methyl groups at C-15,
being oxidized to an acetyl and/or alcohol function. Compounds 152 and 159 have a
hydroxy and acetoxy group present at C-3 respectively while compounds 160 and 161
have an acetyl group at C-2. Abietanes 163 and 164 have a formyloxy (-OCHO) group at
C-19 while the isopropyl group at C-13 has been replaced by a linear, 3-carbon side-
chain containing either a double bond or alcohol in compounds 162-164.
Table 9b: Coleon-type abietanes with an olefinic bond at ∆ 5 isolated from Plectranthus
and Coleus species
Compound Name Synonym
149
150
151
152
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6,11,12,14-tetrahydroxy-
5,8,11,13-abietatetraene-7one
14-acetoxy-6,11,12trihydroxy-5,8,11,13-
abietatetraene-7-one
11-acetoxy-6,12,14trihydroxy-5,8,11,13-
abietatetraene-7-one
3β,6,11,12,14pentahydroxy-5,8,11,13abietatetraene-7-one
Coleon U
14-O-acetylcoleon
U
Coleon U 11
acetate
Isolated from
Plectranthus (P)
or Coleus (C)
species
P. myrianthus;
P.
grandidentatus;
P. forsteri
’marginatus’;
C. carnosus;
P. sanguineus;
P. edulis;
P. fasciculatus
P.
grandidentatus
Coleon S P. caninus
Reference
Wellsow et al., 2006;
Gaspar-Marques et
al., 2006;
Gaspar-Marques et
al., 2002;
Cerqueira et al.,
2004;
Miyase et al., 1977a;
Yoshizaki et al.,
1979;
Matloubi-Moghadam
et al., 1987;
Kunzle et al., 1987;
Coutinho et al.,
2009;
Rasikari, 2007
Rijo et al., 2007
C. xanthanthus Mei et al. 2002
Arihara et al., 1977:
64