Chemistry Reference
In-Depth Information
A series of novel dehydroabietylamine derivatives (
70
-
74
) (
Scheme 6.17
) has been
synthesised and these compounds have been shown to be inhibitors of phospholipase
A2 (PLA2). These compounds exhibit
in vivo
anti-inflammatory activity in the rat
carrageenan paw oedema assay and support the concept of PLA2 inhibition as an
approach to the search for novel anti-inflammatories [47].
Scheme 6.17
Structure of dehydroabietylamine derivatives (
70
-
74
)
6.2.6 Ion Channel Activities
Ion channels play key roles in translating ionic fluxes across cellular membranes
into electrical impulses through their ability to interconvert electrical signals. Large
conductance calcium-activated potassium (BK, or 'big potassium') channels are
expressed in many different types of excitable cells and have significant physiological
roles in the regulation of frequency of firing, action potential repolarisation, and/or
after hyperpolarisation [48]. There are several different BK channels, which may be
particular to tissues and organs [49]. Except for heart myocytes, the BK channels
are expressed in a number of organ systems, such as smooth muscle cells, skeletal
muscle cells, neuronal cells, and secretary epithelial cells, and they have important
physiological roles in modulating muscle contraction and neuronal activities [50].
Although many natural and artificial compounds have been reported to show BK
channel opening activity, their activities are rather weak and nonspecific to BK
channels [51, 52].
