Isolation and chatacterization of homoisoflavonoids from Dracaena cochinchinensis and their osteogenic activities in mouse mesenchymal stem cells.

Two new homoisoflavonoids, dracaeconolide A (1) and dracaeconolide B (2), together with ten known compounds, namely (3R)-7,4'-dihydroxy-8-methoxyhomoisoflavane (3), (3R)-7-hydroxy-3-(4-hydroxybenzyl)chromane (4), (3R)-7,4'-dihydroxy-5-methoxy-homoisoflavane (5), (3R)-6,4'-dihydroxy-8-methoxyhomoisoflavan (6), 7,4'-dihydroxy-8-methylflavan (7), (2R)-7,4'-dihydroxy-5-methoxy-8-methylflavan (8), 5,4'-dihydroxy-7-methoxy-6-methylflavane (9), 7,4'-dihydroxy-3'-methoxyflavan (10), 7,4'-dihydroxyflavan (11), 4,4'-dihydroxy-2,6-dimethoxydihydrochlcone (12), were isolated from the red resin of Dracaena cochinchinensis (dragon's blood, DB). All the compounds were then evaluated for their effects on mouse bone marrow-derived mesenchymal stem cells (MSCs) proliferation using CCK8 assay and their abilities in promoting MSCs differentiating into osteoblast through the assay of alkaline phosphatase (ALP) activity in vitro. Compounds 2, 3, 4, 7, 9, and 11, at a concentration of 10μM with no cytotoxicity, significantly promoted MSC osteogenic differentiation by increasing the levels of ALP activity to percents of 159.6±5.9, 167.6±10.9, 162.0±1.4, 151.3±4.0, 171.0±8.2, and 169.9±7.3 in relative to the control, respectively. The results of ALP staining were in accordance to that of ALP activity.