In order to obtain the biological active compound, alpha-mangostin, from the traditional native mangosteen (Garcinia mangostana L.), an extraction method for industrial application was explored. A high yield of a-mangostin (5.2%) was obtained by extraction from dried mangosteen pericarps with subsequent purification on macroporous resin HPD-400. The chemical structure of alpha-mangostin was verified mass spectrometry (MS), nuclear magnetic resonance (H-1 NMR and C-13 NMR), infrared spectroscopy (IR) and UV-Vis spectroscopy. The purity of the obtained alpha-mangostin was 95.6% as determined by HPLC analysis. The binding of native alpha-mangostin to human serum albumin (HSA) or transferrin (TRF) was explored by combining spectral experiments with molecular modeling. The results showed that amangostin binds to HSA or TRF as static complexes but the binding affinities were different in different systems. The binding constants and thermodynamic parameters were measured by fluorescence spectroscopy and absorbance spectra. The association constant of HSA or TRF binding to alpha-mangostin is 6.4832x10(5) L/mol and 1.4652x10(5) L/mol at 298 K and 7.8619x10(5) L/mol and 1.1582x10(5) L/mol at 310 K, respectively. The binding distance, the energy transfer efficiency between alpha-mangostin and HSA or TRF were also obtained by virtue of the Forster theory of non-radiation energy transfer. The effect of alpha-mangostin on the HSA or TRF conformation was analyzed by synchronous spectrometry and fluorescence polarization studies. Molecular docking results reveal that the main interaction between amangostin and HSA is hydrophobic interactions, while the main interaction between alpha-mangostin and TRF is hydrogen bonding and Van der Waals forces. These results are consistent with spectral results.