Chemical constituents, biological activities, and quality evaluation of agarwood produced from the qi-nan germplasm of Aquilaria sinensis

Agarwood, chenxiang, is a traditional Chinese medicine. It is the resinous heartwood of Aquilaria sinensis. The qinan germplasm of A. sinensis is a high-quality resource. This study aimed to investigate the chemical compounds and biological activities of agarwood produced from the qi-nan germplasm (QNA) and evaluated the quality of the QNA according to existing standards. The QNA was extracted by using supercritical CO2 (SCE) and then by 90 % EtOH (ETE). SCE was detected with gas chromatography-mass spectrometry (GC-MS) to identify 13 compounds, including sesquiterpenoids and 2-(2-phenylethyl)chromones. ETE was isolated by using column chromatography methods to yield two new compounds: 5-hydroxy-2-[2-(4-methoxy)phenethyl]chromone (1) and qinansin A (2), and 13 known compounds (3-15). The various biological activities of SCE, ETE, and these isolated compounds were evaluated. Compound 1 , compound 2 , 2-(2-phenylethyl)chromone (4), 2-[2(-4methoxy)phenethyl]chromone (5), 2-[2-(2-hydroxy)phenethyl]chromone (6), chenanone A (8), (E)-1-chloro-4- (4-methoxyphenyl) but-3-en-2-one (9), (E)-1,5-diphenylpentan-1-en-3-one (12), and selina-4,11(13)-diene12,15-dial (14) demonstrated antifungal activity against Epidermophyton floccosum, Trichophyton rubrum, and Microsporum gypseum, with IC50 values ranging from 3.50-83.45 mu & Mcy;. Moreover, compound 12 exhibited antiinflammatory activity (NO production inhibition; IC50 = 23.42 mu M); additionally, compound 8 showed antioxidant activity (DPPH free radical scavenging; IC50 = 40.89 mu M), and compound 14 showed cytotoxicity to five cancer cell lines and human normal lung epithelial BEAS-2B cells, with IC50 values ranging from 3.35-16.95 mu M. The quality of the QNA was evaluated according to the Chinese Pharmacopoeia and the local standards of Hainan Province, China. The findings indicated that the alcoholic extract contents and the contents of 2-(2-phenylethyl) chromone and 2-[2-(4-methoxyphenyl)ethyl]chromone of QNA were within high-quality ranges, and they increased with prolonged agarwood formation time. These results could provide a basis for the further development and utilization of QNA.