UFLC-PDA fingerprint of Tibetan medicine Pterocephalus hookeir Determination of loganin in Pterocephalus hookeri by HPLC Identification of new chemical constituents of Tibetan medicinal herb Halenia elliptica Identification of Tibetan medicine “Dida” of Gentianaceae using DNA barcoding HPLC fingerprint of Tibetan medicine Shaji Gao HPLC fingerprints of Tibetan medicinal herb “Songdi”