Combination of DNA isolation and RP-HPLC analysis method for bark samples of Saraca asoca and its adulterant.

DNA fingerprinting singly or in combination with phytochemical analysis is ideal for quality control of crude plant-based drugs. However, when the source material is tannin rich stem bark, extraction of DNA by conventional methods becomes challenging. In such cases, phytochemical profiling serves as very useful tool for its identification. The work herein described a method for simultaneous DNA isolation and phytochemical extraction for downstream analysis and applications from dried bark powder of Saraca asoca and commercial samples of this crude drug as well as from those of Polyalthia longifolia, its most common adulterant. It is a modified CTAB-based method which involves a pre-extraction step by soaking samples overnight in de-ionized water followed by filtration. The residues in the filter paper were used for DNA isolation and dried filtrate was used for Reverse Phase-High-Performance Liquid Chromatography analysis. Results revealed that genomic DNA isolated was PCR amplifiable with Inter Simple Sequence Repeat and Start Codon Targeted markers. Phenolic compounds of catechin, epicatechin, and gallic acid were detected from the above dried filtrate. The method is simple, reliable and it requires small amount of sample with an option of integrating both phytochemical and DNA-based profiling, from the same starting material. Therefore, the present method could be useful for further potential applications such as quality control assessment of S. asoca products.