Identification of black pine (Pinus nigra Arn.) heartwood as a rich source of bioactive stilbenes by qNMR.

BACKGROUND: Recently published studies have demonstrated the strong anti-inflammatory properties of Scots pine (Pinus sylvestris L.) heartwood extracts, related to its stilbene content. In order to find alternative sources of Pinus heartwood extracts rich in stilbenes, a large number of samples were investigated, using a new developed high-throughput screening method based on quantitative nuclear magnetic resonance.

RESULTS: The new method enabled us to measure the levels of pinosylvin, pinosylvin monomethyl ether and pinosylvin dimethyl ether in heartwood extracts in only 45 s per sample. The method was applied to 260 Pinus nigra trees originating from Peloponnese (southern Greece) from four different natural populations of the species. The results obtained showed that the total stilbenoids per dry heartwood weight varied greatly, ranging from 10.9 to 128.2 mg g(-1)drywood (average 59.92 ± 21.79 mg g(-1)drywood ). The major stilbene in all cases was pinosylvin monomethyl ether (40.32 ± 15.55 mg g(-1)drywood ), followed by pinosylvin (17.07±6.76 mg g(-1)drywood ) and pinosylvin dimethyl ether (2.54 ± 1.22 mg g(-1)drywood ). The highest stilbene content of P. nigra samples was found to be 6.3 times higher than the highest reported figure for P. sylvestris L.

CONCLUSION: Pinus nigra heartwood is the richest source of pinosylvin and pinosylvin monomethyl ether identified to date and can be considered the best natural resource for production of bioactive extracts. © 2016 Society of Chemical Industry.