HPTLC Fingerprints as Tool to Study Effect of Geographical Condition on Plant Metabolites

In the field of botanical drugs, authentication of plants is very important. Usually authentication has been based on morphology and microscopy of the plant i.e. anatomy is a reliable technique but in the case of medicinal plants, metabolomic fingerprints are also enjoying a supportive role for the same. Chromatographic fingerprints can also be use to study the effect of geographical conditions on the production of secondary metabolites and for identification of best chemotype, which can be further used for enhanced commercial production of lead molecule from the crude drugs. In the current study rhizomes of Coleus forskohlii were collected from different regions of India, their extraction was carried out in methanol by maceration at 60°C. Extracts were concentrated and each one was made up to 10 mL. The fingerprints were developed on aluminium TLC plates precoated with silica gel 60F-254 using solvent system toluene: methanol (18:1.5, v/v), which gives multiple bands along with well marked and compact spot of forskolin (Rf value 0.27±0.02). Anisaldehyde sulphuric acid was used for spraying and later the plate was heated at 105°C for 5min. Densitometric analysis of was performed in absorbance mode at 545nm. Chromatographic fingerprinting showed good separation of components, and it can be concluded from the chromatogram that the sample collected from Aligarh, Ahmadabad, Coimbtore, Salem, Salgali are a rich source of secondary metabolites. Forskolin content was found highest in sample collected from Bengaluru 0.239%(w/w) due to variation in geographical condition.

Acknowledgement: Authors are thankful to AICTE India for financial assistance to the studies