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Elucidation of key anti‐inflammatory constituents from Echinacea angustifolia by bioactivity directed fractionation
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.889.4
Subject(s) - fractionation , chemistry , fraction (chemistry) , anti inflammatory , chromatography , lipopolysaccharide , echinacea (animal) , traditional medicine , pharmacology , biology , medicine , endocrinology
Bioactivity guided, semi‐preparative reversed phased HPLC fractionation was employed to elucidate interacting anti‐inflammatory constituents from Echinacea angustifolia . The first round of fractionation produced five fractions from a Soxhlet EtOH extract. Fractions were screened for anti‐inflammatory properties in lipopolysaccharide treated RAW264.7 mouse macrophage cells. Prostaglandin E2 (PGE 2 ) production was significantly (p<0.05) reduced by 49% with fraction 3 (1 μg/ml), an alkamide rich fraction that was then further fractionated into fractions 3A–3E. The PGE 2 assay determined that fractions 3D and 3E (each 1 μg/ml) were significantly bioactive, reducing PGE 2 production by 51% and 62%, respectively (p<0.001). LC‐MS analysis identified strong signals for Bauer alkamides 10 and 11 present in fraction 3E. Chemically synthesized Bauer alkamides 10 and 11 were combined at concentrations present in fraction 3E and analyzed for PGE 2 production inhibition. The combination did not entirely explain the PGE 2 inhibition seen with fraction 3E. Further fractionation of fractions 3D and 3E yielded 8 additional fractions that significantly inhibited PGE 2 production (p<0.05). GC‐MS analysis was conducted on 5 third round fractions, identifying 3 possible new alkamides. Structural elucidation of these constituents is on going.