This research work concerns with the chemical constituents and pharmacological studies of three medicinal plants, Phyla nodiflora (Verbenaceae) Ruellia patula and Ruellia brittoniana (Acanthaceae).
During the chemical investigation 12 compounds of different classes were isolated from Phyla nodiflora. A new triterpene, 3β,19α-dihydroxy-urs-12,20(30) diene was obtained as a minor constituent while porno lie acid, ursolic acid, catalpol, loganin, and α-ethyl galactose were isolated for the first time from this plant. Along with these compounds some reported compounds, luteolin-7-0-glucoside, β-sitosterol glucoside, stigmasterol glucoside, maltose, α D-glucose, α -D-fructose and α -D-xylose were also identified from this plant. From Ruellia patula 9 compounds were isolated. A new lignan glycoside 5,5' -dimethoxylariciresinol-9-0-β-D-glucopyranoside was characterized along with other known compounds, as lyoniresinol, 9-0- β-D-glucopyranoside, apigenin-7-0 rutinoside, β-sitosterol, lupeol, α -ethyl galactose, α -D-glucose, β-D-glucose, and β -D fructose.
From Ruellia brittoniana five compounds of different classes were isolated. Two new compounds 2-0- α-D-galactopyranosyIgIycerol hexaacetate and a dimer of methyl-2,4-diene-hexandioate were obtained. In addition to these new compounds, three reported compounds, lyuniresinol-9-0-β-D-glucopyranoside, α-ethyl-galactose and paramethoxy benzoic acid were isolated for the first time from this plant.
During the isolation of aforementioned naturally occurring compounds different chromatographic techniques were used and the structure elucidations were carried out by UV, IR, MS, IH-NMR and 13C-NMR spectra. For the determination of absolute structural configuration, X-ray crystallographic technique was used for two compounds, i.e., 2-0-α-D-galactopyranosylglycerol hexaacetate and α-ethyl-galactose.
In pharmacological investigation different extracts and fractions of the three plants i.e. crude extract, aqueous and n-butanolic fractions, were used for cardiovascular screening. The cardiovascular experiments were carried out in vitro and vivo. In case of vitro experiments isolated rabbit heart was used while in vivo anaesthetized rats were used.
In vitro experiments, all the extract.; and fractions of three plants appeared to be cardiotonic except the n-butanolic fraction of R. brittoniana. The cardiotonic activities were found through the β-receptors, because in the presence of a standard drug, propranolol, their activity exhibited depressing effects.
In vivo experiments, all the extracts of P. nodiflora and R. brittoniana displayed hypotensive activity, while extracts of R. patula showed a hypertensive activity in pantothal sodium anaesthetized rats.
During the screening of pure compounds on mean arterial blood pressure in pentothal sodium anaesthetized rats, the compound 2-0-α-galactopyranosylglycerol hexaacetate initially increased the blood pressure and soon it became lethal. The compound α-ethylgalactose showed a hypertensive effect. The compound 3β,19 α-dihydroxy-urs-12,20(30)-diene exhibited antihypertensive activity in pentothal sodium anaesthetized rats. Hypotension and bradycardia were observed in a dose dependent manner.