CHEMICAL AND BIOLOGICAL INVESTIGATION OF THE ROOT BARK OF CLERODENDRUM-MANDARINORUM

A 70% EtOH extract of Clerodendrum mandarinorum root bark was assessed for CNS activity against 18 radioligand receptor binding assays. The results showed that the extract was able to bind to opiate, adenosine- 1, alpha 2-adrenergic, 5HT-1, 5HT-2, dopamine-2, histamine-1, GABA(A), and GABA(B) receptors. Fourteen compounds were isolated and identifie d by EI-MS, H-1-NMR and C-13-NMR spectra as known triterpenoids (fried elanone, lupeol, betulinic acid), steroids (245-stigmata-5,25-dien-3 b eta-ol, 22E,245-stigmata-5,22,25-trien-3 beta-ol), flavonoids (cirsima ritin, cirsimaritin-4'-glucoside, quercetin-3-methyl ether), tetrahydr o-alpha-pyrone and saccharides (sucrose, alpha-D- and beta-D-glucopyra nose, ethyl-alpha-D-glucopyranoside, 2-ethyl-beta-D-fructofuranoside). The isolated compounds were assessed for activity by the radioligand receptor binding assays. Betulinic acid and ethyl-alpha-D-glucopyranos ide showed weak activities against sulphonylureas (IC50 = 7.5 mu M) an d muscarinic receptors (IC50 = 5.5 mu M), respectively. Cirsimaritin-4 '-glucoside was weakly active in the adenosine-l binding assay (IC50 = 3.0 mu M), whereas seven structurally related flavonoids, not isolate d from C. mandarinorum, were inactive.