Chemical Constitution And Bioactivity Of Abies Spectabilis(D.Don) Spach

Abies spectabilis(D.Don) spach Van Tiegh belongs to Abies genus of the Pinaceae family distributing mainly in the highland of the south Tibet province. In the anti-proliferative test against human tumor cells, the CHCl3-soluble fraction of its crude extract showed potent anti-proliferative activities against four human tumor cells, especially for Colo205 and MDA-MB-435 (IC50 = 12.5, 3.05μg/mL, ). As a further research analyzing the chemical constituents form Abies species in China,we then examined the constituents of Abies spectabilis.Phytochemical investigations on Abies spectabilis afforded 70 chemical constituents. On the basis of physical and spectroscopic data, including 1D and 2D homo- and heteronuclear NMR experiments (HSQC, 1H–1H COSY, HMBC, and NOESY), and by comparison with the literatural references, three triterpenoids, 23 diterpenoids, 1 sesquiterpenoid, 14 flavonoids, 12 lignans, and 17 other compounds were identified, of which three new compounds were identified as 12α-methoxy-7,13-dien-18-oic acid (1), 7α-methoxy-dehydroabietic acid (2), and 5-hydroxy-6-methyl-7,4'-dimethoxyflavone-8-O-β- D-glucopyranoside (28).Twenty three diterpenoids and three triterpenoids were tested for antitumor activities against four tumor cell lines including A549, COLO-25, QGY-25, and THP-1. The results showed that none gave positive effect (IC50>100μg/mL). In bioassay against LPS-induced NO production in RAW 264.7 macrophages, 3 showed strong effects with IC50 value of 17.8μg/mL and 12 and 26 show moderate effects with IC50 value of 40.4 and 40.9μg/mL.Although triterpenes are commonly found in Abies plants, most are lanostanes together with minor cycloartanes. Interestingly, three serratane triterpenes were isolated and identified for the first time from Abies spectabilis instead of lanostanes or cycloartanes triterpenes. So serratanes could be used as indicative compounds for Abies spectabilis from the other Abies species. Since norditerpenes had never been reported from the Abies plants occurring out of China, it is of great chemotaxonomic significance for norditerpenoids as the characteristics of Abies species in China. This study also confirmed that phenols are found mainly from Asian species, while lignans exist widely around this genus.