TY - JOUR A1 - Ilkei, Viktor A1 - Spaits, András A1 - Prechl, Anita A1 - Szigetvári, Áron A1 - Béni, Zoltán A1 - Dékány, Miklós A1 - Szántay, Csaba, Jr A1 - Müller, Judit A1 - Könczöl, Árpád A1 - Szappanos, Ádám A1 - Mándi, Attila A1 - Antus, Sándor A1 - Martins, Ana A1 - Hunyadi, Attila A1 - Balogh, György Tibor A1 - Kalaus (†), György A1 - Bölcskei, Hedvig A1 - Hazai, László A1 - Kurtán, Tibor T1 - Biomimetic synthesis and HPLC–ECD analysis of the isomers of dracocephins A and B JF - Beilstein Journal of Organic Chemistry PY - 2016/// VL - 12 SP - 2523 EP - 2534 SN - 1860-5397 DO - 10.3762/bjoc.12.247 PB - Beilstein-Institut JA - Beilstein J. Org. Chem. UR - https://doi.org/10.3762/bjoc.12.247 KW - absolute configuration KW - Dracocephalum rupestre KW - dracocephins A–B KW - ECD calculation KW - flavonoid alkaloids KW - HPLC–ECD N2 - Starting from racemic naringenin ((±)-1), a mixture of dracocephin A stereoisomers 6-(2”-pyrrolidinone-5”-yl)naringenin (±)-2a–d and its regioisomer, dracocephin B 8-(2”-pyrrolidinone-5”-yl)naringenin (±)-3a–d originally isolated from Dracocephalum rupestre, have been synthesized in a one-pot reaction. The separation of 2a–d and 3a–d was achieved by preparative HPLC. The four stereoisomers of each natural product were separated by analytical chiral HPLC and their absolute configuration was studied by the combination of HPLC–ECD measurements and TDDFT–ECD calculations. The synthesized flavonoid alkaloids were further characterized by physicochemical and in vitro pharmacological studies. ER -