Chemistry Reference
In-Depth Information
over infected confluent monolayers of HeLa cells at a concentration of 6.25 mg/mL
(nearly the same activity as acyclovir). The replacement of the ester by a hydroxyl
group at C18 enhanced the antiviral activity [14]. The dehydroabietane that showed
the highest antiviral activity was dehydroabietinol acetate (
13
) [15]. Dehydroabietinol
acetate (
13
) was found to be slightly active against HSV-1 over infected confluent
monolayers of Vero cells at a concentration of 25 mg/mL.
The synthetic catechol (
14
) from abietic acid has been evaluated for its antiviral
activity against (HSV-1, herpes simplex virus type 2 (HSV-2), vaccinia virus and
African swine fever virus and compared with that of carnosic acid (
18
). The catechol
(
14
) had a stronger effect on the viruses studied than did carnosic acid (
18
). The
two compounds were also evaluated against Human Immunodeficiency Virus type 1
(HIV-1, NL4-3 strain). The results obtained indicated that the effective concentration
to achieve 50% protection (EC
50
) for carnosic acid (
18
) (EC
50
= 458 μM) was higher
than for catechol (
14
) (EC
50
= 275 μM) [17].
Kinouchi and co-workers [25] reported a rearranged labdane type diterpenoid,
methyl 15-hydroxy-7-oxo-dehydroabietate (
37
), isolated from the cones of
Pinus
luchuensis
, showed potent inhibitory effects on EBV-EA activation induced by the
tumour promoter TPA with 100% inhibition of induction at 1000 mol ratio:TPA
(
Scheme 6.9
), about 70-80% inhibition at 500 mol ratio:TPA, and about 25-40%
inhibition at 100 mol ratio: TPA on EBV-EA induction by TPA. Tagat and co-workers
[26] reported that dehydroabietic acid can be converted into the exocyclic olefin by
applying the Barton decarboxylation protocol. The exocyclic olefin served as key
intermediate for the stereoselective synthesis of the ring-A functionalised derivatives
(
38
-
39
). These two compounds turned out to be active against HSV-2 in the standard
plaque assay and seemed to interfere with an early event in viral replication. Their
IC
50
values were 3.0 and 8.0 μg/mL, respectively.
Scheme 6.9
Structure of compounds (
37
-
39
)
