R. Arboreum Flower and Leaf Extracts: Rp-hptlc Screening, Isolation, Characterization and Biological Activity

In the present study, preliminary in-vitro anticancer screening of the alcoholic extracts of leaves (LE) and flowers (FE) of Rhododendron arboreum was performed against Crown Gall tumor and MCF-7 breast cancer cell lines. Both the extracts showed prominent inhibition in the development of Crown Gall tumor in potato discs while only LE was found to be significantly effective against MCF-7. Three terpenoids (1-3), one sterol (4) and two flavonoids (5-6) were isolated from the LE of the Rhododendron arboreum. The flavonoidal compounds, quercetin and rutin were simultaneously identified from the flowers and leaves using high-performance thin-layer chromatography (HPTLC). Precoated silica-gel RP-18 F 254 S plates were used with a mobile phase of methanol: water: formic acid (55: 42: 03 v/v/v) and densitometric determination of these compounds were carried out at 254 nm in absorbance mode. Structures of all the isolated compounds were elucidated by spectroscopic methods like IR, PMR, CMR and Mass spectrometry.