Prenylated 2-arylbenzofuran derivatives with potent antioxidant properties from Chlorophora regia (Moraceae)

• Three new 2-arylbenzofuran and one new prenylated flavonol were isolated from the stem bark of Chlorophora regia.
• Fifteen known compounds were isolated in parallel, for the first time from C. regia.
• Free radical scavenging properties and anti-inflammatory activities of the compounds were evaluated.
• Compounds 1, 2, 5, 9 and 15 showed remarkable free radical scavenging properties.
• None of the tested compounds demonstrated any anti-inflammatory activity.

Extracts of Chlorophora regia are frequently used in Ghana in traditional medicine. There is, however, no reported data on the chemical composition of the plant. Comprehensive phytochemical investigation of the stem bark of C. regia resulted in the isolation of three new prenylated 2-arylbenzofuran derivatives, regiafuran A–C (1–3), and one new prenylated flavonol (4), together with fifteen known compounds (5–19). Their structures were elucidated by combined spectroscopic analysis of their NMR and HRESI-MSn data. Compounds 1, 2, 5, 9 and 15 exhibited remarkable free radical scavenging properties with IC50 values of 1.9 μg/ml, 2.4 μg/ml, 2.2 μg/ml, 2.1 μg/ml and 1.8 μg/ml, respectively, compared to the standard trolox (IC50 1.1 μg/ml). The isolated compounds did not, however, show any anti-inflammatory potential when tested using a PGE2 (prostaglandin E2) competitive enzyme immunoassay.

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