The genus Goniothalamus comprises about 160 species of shrubs and trees growing in tropical and subtropical Asia. 1) Many of these species are used for timber, as fiber sources, as mosquito repellant, and most interestingly in folk medicine in several countries. 2,3) Phytochemical studies of Goniothalamus species have led to the isolation and characterization of a large number of styryl-lactones. These can be classified into several main subtypes: styryl-pyrones, furano-pyrones, furano-furones, and pyrano-pyrones. 4) Styryl-lactones possess significant cytotoxic activity against several human tumor cell lines such as A-549 (lung carcinoma), HT-29 (colon adenocarcinoma), MCF-7 (breast carcinoma), RPMI (melanoma), U251 (brain carcinoma), 3,5) and to induce apoptosis in HL-60 leukemic cell. 6) Some of styryl-lactones have been synthesized via total synthesis. 3,7-10) Goniopypyrone, the first pyrano-pyrone compound, was first isolated in 1990 from G. giganteus. 11,12) It was high bioactive, showing ED 50 values of ca. 0.67 mg/ml in the cytotoxicity of human tumor cell lines (A-549, MCF-7, HT-29), high toxicity to the brine shrimp (BS), and significant inhibition of the formation of crown gall tumors on potato discs (PD). Typically, up to date, pyrano-pyrone compounds are found in some Goniothalamus species.The formation of bone involves a complex series of events, including the proliferation and differentiation of osteoprogenitor cells. Eventually, this results in the formation of a mineralized extracellular matrix. Most effective osteoporosis therapies reduce bone loss but do not restore lost bone mass and strength. Therefore, it is desirable to discover bone-building (anabolic) agents that stimulate new bone formation and correct the imbalance of microarchitecture characteristic of established osteoporosis. 13) As new bone formation is primarily a function of the osteoblasts, agents that regulate bone formation act either by increasing the proliferation of cells in the osteoblastic lineage or inducing osteoblast differentiation. 13,14) Early intervention is now possible with the help of some effective medications, which may reduce the risk of first and recurrent fractures.In our investigation of phytochemistry of the leaves of G. tamirensis, 9-deoxygoniopypyrone (2) and a new pyranopyrone, (ϩ)-8-epi-9-deoxygoniopypyrone (1), were isolated and identified using spectral methods. To investigate whether these compounds could stimulate the function of osteoblasts, their effects on cell growth, collagen content, alkaline phosphatase (ALP) activity, and calcium deposition were assessed in the pre-osteoblastic target cell line, MC3T3-E1, which is a well-characterized in vitro model of osteoblast differentiation. 15)
Results and DiscussionCompound 1 Science and Technology; 18 Hoang Quoc Viet St., Caugiay, Hanoi, Vietnam: and c Faculty of Chemistry, Hanoi University of Science; 19 Le Thanh Tong St., Hoankiem, Hanoi, Vietnam. Received November 24, 2009; accepted January 8, 2010; published online January 19, 2010 The n...