title: Role of thin-layer chromatography in ascertaining Kashaya Rasa (astringent taste) in medicinal plants on the concept of Samana and Vichitra Pratyayarabdha principles of Ayurveda.
abstract: BACKGROUND
  Pharmacodynamics, in Ayurveda has been described in terms of Rasadipanchaka. Rasa, on one side indicates the Bhautika composition of the drug and on the other side predicts the action. Different analytical techniques, pharmaceutical processes are being used in Ayurveda for the purpose of standardization of raw drugs.
  
  
  OBJECTIVE
  In this study an attempt has been made to apply chromatographic technique in determination of Kashaya (astringent) Rasa (taste).
  
  
  METHODS
  Two important Kashaya dominant drugs Kulattha (Dolichos biflorus Linn.) and Kanchanara (Bauhinia variegata Linn.), falling under Vichitra and Samana Pratyayarabdha category respectively, were subjected to physicochemical parameters and qualitative tests followed by High-Performance Thin-Layer Chromatography (HPTLC). In light of chromatographic fingerprinting; sample preparation protocol is modified to incorporate taste threshold in correlation. Column chromatography is used for first-level discrimination technique followed by HPTLC. Kashaya Rasa Dominant Zone (KsRDZ) was separated and subjected to TLC fingerprinting. The KsRDZ fraction was designated as Botanical Reference Material (BRM) in further analysis.
  
  
  RESULTS
  Ash value, Alcohol and water soluble extract value were more in B variegata as compared to D biflorus. Presence of tannin in both the samples was confirmed through qualitative test. The KsRDZ fraction separated at Rf 0.46 and 0.48 for Kulattha and Kanchanara respectively.
  
  
  CONCLUSIONS
  The results showed that the planner chromatography technique seems very useful when BRM hypothesis was adjunct to method that explains the categorization according to traditional Rasa domain classification method.
authors.affiliation: Department of Dravyaguna, Institute for Post Graduate Teaching and Research in Ayurveda, Gujarat Ayurved University, Jamnagar, Gujarat, India.
authors.forename: Rasika H
authors.initials: RH
authors.lastname: Kolhe
authors.affiliation: Department of Dravyaguna, Institute for Post Graduate Teaching and Research in Ayurveda, Gujarat Ayurved University, Jamnagar, Gujarat, India.
authors.forename: Rabinarayan
authors.initials: R
authors.lastname: Acharya
authors.affiliation: Department of Pharmaceutical Chemistry Laboratory, Institute for Post Graduate Teaching and Research in Ayurveda, Gujarat Ayurved University, Jamnagar, Gujarat, India.
authors.forename: Vinay J
authors.initials: VJ
authors.lastname: Shukla
keywords: Column chromatography; Rasa; high-performance thin-layer chromatography; spectral comparison; taste threshold