Planta Med 2015; 81 - PW_201
DOI: 10.1055/s-0035-1565825

Flower metabolomics: volatile compound profile, antioxidant capacity and LC-MS-TOF identification of flavonoids in various tropical flowers

E Stashenko 1, J Mejía 1, LJ Sierra 1, DC Bernal 1, L Gualteros 1, K Carrillo 1, JR Martínez 1
  • 1Research Center for Biomolecules, CENIVAM, Universidad Industrial de Santander, Bucaramanga, Colombia

Volatile organic compounds in Brownea macrophylla, Petrea volubilis and Hibiscus spp. flowers were sampled in vitro and in vivo with HS-SPME and analyzed by GC-MS. Flavonoids present in flower extracts, were identified with LC-MS and their antioxidant capacity was evaluated with the ORAC assay. LC-MS data obtained in positive ionization mode from extracts were used to generate possible molecular formulas that satisfied the accurate masses. Fragmentation and mass errors were used as selection criteria for structure assignment. Pelargonidin-3,5-glucoside, pelargonidin-3-glucoside, 8-p-hydroxybenzyl and peonidin were identified in the B. macrophylla extract. Pelargonidin glucuronide, apigenin 7-glucuronide methyl ester, cyanidin-3-O-glucuronide, pelargonidin-3-O-(6-acetyl-glucoside), and delphinidin-3-glucoside were found in the P. volubilis flower extract. Cyanidin-3-glucoside, cyanidin-3,5-glucoside, delphinidin-3-glucoside, and peonidin-3-arabinoside were identified in the Hibiscus spp. extract. ORAC antioxidant capacity values of 3460, 670 and (1200 – 4035) micromol Trolox/g of substance, were measured for the B. macrophylla, P. volubilis and Hibiscus spp. extracts, respectively. These were higher than the values of 500 and 480 micromol Trolox/g of substance observed for the reference antioxidants, BHT and α-tocopherol, respectively. B. macrophylla, P. volubilis and Hibiscus spp. flowers were obtained from experimental plots at the CENIVAM research center. The plant material was freeze-dried (Virtis Advance Plus). Solid-liquid extraction with acidified (1% HCl) ethanol-water (3:1, v/v) afforded extracts which were roto-evaporated. An LC-MS with electro-spray ionization (LC-ESI-TOF, 1200 – 6210 Agilent Technologies, Palo Alto, CA, USA) was used for extract analysis. The ORAC assay was implemented in a 96-well microplate reader (Turner Biosystems Inc., Modulus Microplate Reader II).