New Δ-tocotrienol derivatives from Colombian propolis

• Published in: Natural product research Vol. 34; no. 19; pp. 2779 - 2786
• Main Authors: Popova, Milena P., Trusheva, Boryana S., Nedialkov, Paraskev T., Tsvetkova, Iva, Pardo-Mora, Dolly P., Najdenski, Hristo, Torres-García, Orlando A., Sforcin, José M., Bankova, Vassya S.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01-10-2020; Taylor & Francis Ltd
• Subjects: Acids; Antiinfectives and antibacterials; Antimicrobial activity; Antioxidants; Derivatives; DPPH scavenging activity; garcinoic acid; Propolis; Scavenging; Tocopherol; Vitamin E; δ-tocotrienol derivatives; garcinoic acid; antimicrobial activity; DPPH scavenging activity; Propolis; δ-tocotrienol derivatives
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786419.2019.1590710

Two new δ-tocotrienol derivatives with oxidized terminal chain: 5,6-dioxo-garcinoic acid (trans-13′-carboxy-5,6-dioxo-δ-tocotrienol) (2) and 5-hydroxy-8b-oxo garcinoic acid (trans-13′-carboxy-5-hydroxy-8b-oxo-δ-tocotrienol) (3), together with one known derivative garcinoic acid (trans-13′-carboxy-δ-tocotrienol) (1) were isolated from a Colombian propolis. Garcinoic acid was found as a propolis constituent for the first time. The isolated compounds and crude ethanolic extract demonstrated high antimicrobial activity against Staphylococcus aureus and Candida albicans (MICs range: 10-39 μg/ml) as well as promising antioxidant potential in DPPH assay. Compound 3 displayed highest radical scavenging activity, even higher than that of dl-α-tocopherol, used as a positive control.