Fingerprint Study of Thymus spp. by TLC

Background: thymus is a widely used medicinal plant in food and pharmaceutical industries.among different species of thymus, t. vulgaris is used more than other species in therapeuticdosage forms.objective: this study was conducted to differentiate various thymus species by tlcfingerprint.methods: in order to identify and differentiate various species of thymus, tlc fingerprints ofessential oil, dichloromethane, ethylacetate and n-butanol extracts of four available speciesnamed t. vulgaris, t. pubescens, t. citriodorus and t. daenensis were obtained and comparedwith each other.results: the results showed that the tlc chromatograms of essential oil and n-butanol extractcan not be used as differential identification for the above-mentioned species; while theethylacetate and dichloromethane extracts are more reliable to be used for tlc fingerprints.tlc chromatogram of ethylacetate extract is specific for identification of t. pubescens andt. vulgaris while t. citriodorus and t. daenensis can be best identified by their tlc fingerprintsobtained from dichloromethane extract.conclusion: for best differentiation of various thymus species, different extracts of the plantsshould be used.