Isolation and characterisation of selected germander diterpenoids from authenticated Teucrium chamaedrys and T. canadense by HPLC, HPLC‐MS and NMR

Abstract

Teucrium species, such as germander, are rich in neo-clerodane diterpenoids and have been used in traditional folk medicine for their stimulant, diuretic, antipyretic and antiseptic properties. However, the furano neo-clerodane diterpenoids present in germander have been implicated in the in vivo hepatotoxicity of this botanical. In this study, authenticated germander (Teucrium chamaedrys L. and Teucrium canadense L.) was used as the source material. Methanol extracts of powdered plant mate rial were prepared and analysed by HPLC using Synergi Max-RP columns with monitoring at 220 nm. Limited amounts of teucrin A and other diterpenoid standards were analysed on a Synergi Max-RP column in order to determine their retention times and to generate calibration curves. The same standards were subjected to concurrent mass spectral analysis. Teucrin A and diterpenoids such as dihydroteugin, teuflin, teuflidin and teucvidin were tentatively identified in the plant extracts by HPLC-MS and 1H-NMR experiments. For the isolation of teucrium diterpenoids on a semipreparative scale, a solid-phase extraction method was developed for the first time using styrene divinylbenzene and strata-X sorbents for teucrin A and teuflin, respectively. Semi-preparative HPLC of the methanol extract of the powdered aerial parts of Teucrium plants was carried out on a semipreparative Synergi Max-RP column with photodiode array detection in order to confirm the identities of some diterpenoids by HPLC-MS and NMR.

Comparison of the phenolic component profiles of skullcap (Scutellaria lateriflora) and germander (Teucrium canadense and T. chamaedrys), a potentially hepatotoxic adulterant

“…This approach has been used previously for the determination of terpenoids in several plants, including the terpene lactones in Ginkgo biloba leaves and products (Lin et al , 2008). The structures of the seven diterpenoids reported in the literature (Sundaresan et al , 2006) for T. canadense and T. chamaedrys are shown in Fig. 1.…”

“…Detection of the diterpenoids of the two Teucrium plants (Sundaresan et al , 2006; Fig. 1) was accomplished in the SIM mode by monitoring m/z 329/327 (PI/NI) for teuflin and teucvidin (MW = 328), m/z 345/343 for teucrin A, teuflidin and isoteuflidin (MW = 344), m/z 377/375 for dihydroteugin (MW = 376) and m/z 391/389 for teucrin G (MW = 390).…”

“…1) (Bedir et al , 2003; Sundaresan et al , 2006; Rader et al , 2007). The hepatotoxicity of Teucrium arises from the bioactivation of teucrin A by cytochrome P450 to create reactive metabolites (Kouzi et al , 1994; Haouzi et al , 2000).…”

Disposition Pathways and Pharmacokinetics of Herbal Medicines in Humans

“…Germander caused hepatotoxicity in animals and humans. Germander contains saponins, glycosides, flavonoids and furano neoclerodane diterpenoids [166]. The hepatotoxicity has been ascribed to the diterpenoids including teucrin A and teuchamaedryn A.…”

Comparative study of genotoxicity and antimutagenicity of methanolic extracts from Teucrium chamaedrys and Teucrium montanum in human lymphocytes using micronucleus assay

“…These species are known for their medicinal and biological properties such as hypoglycemic, hypolipidemic, hepatoprotective, antipyretic, anti-inflammatory, antiulcerogenic, antitumor and antimicrobial activities (Rasekh et al 2001;Baluchnejadmojarad et al 2005;Sundaresan et al 2006;Vuković et al 2007;Shtukmaster et al 2010;Sghaier et al 2011a;Sghaier et al 2011b). Many species of this genus show antimicrobial, antioxidant and antifungal activities and are used in food industry (Salah et al 2006;Ozkan et al 2007;Ahmad et al 2008).…”