Study On The Extraction, Synthesis And Analysis Of Mangostins And Their Properties

Mangostins have antioxidant, antibacterial, antiinflammatory, antitumor, antithrombotic activity, and also can inhibit HIV virus. Due to these biologically activity, mangostins were paid much more attention at home and abroad in the recent years. Our research focused on the preparation, purification, characterization and determinnation ofα-mangostin andγ-mangostin. The main contents and conclusions are as following:(1) Highly pureα-mangostin was prepared from raw material of pericap of manosteen through dissolution, extraction, distillation and crystallization. Meanwhile its structure was identified by IR, ¹HNMR and MS, and the content was determined by HPLC, the purity reached to 96.36%.(2)γ-mangostin was synthesized fromα-mangostin by a demethyl reaction. The product was identified by IR, ¹HNMR and MS, and the content was determined by HPLC with the purity of 96.83%.(3) A novel fluorophotometry for determination ofγ-mangostin in the mixture ofα- andγ-mangostin was established based on the study of UV/vis and fluorescence spectra. The fluorescence intensity was proportional to the concentration of theγ-mangostin in the range of 1.0×10^-6 and 6.0×10^-5 mol·L^-1, the detection limit was 4.7×10^-7 mol·L^-1. The recovery test and the comparison of the results with the HPLC method show that the proposed fluorophotometry is simple and reliable.(4)α-mangostin andγ-mangostin were determined simultaneous by HPLC-UVD. The compounds were analyzed by a C18 column with the mobile phase of acetonitrile:0.1%H₃ PO₄ (90:10), the flow rate was 1.0 mL·min^-1 and the detection wavelength was set at 308 nm. The corresponding peak areas were proportional to the concentration within 0.30-44.0mg·L^-1 forα-mangostin, and within 0.80-44.0 mg·L^-1 forγ-mangostin. The limit detections were 0.16 mg·L^-1 and 0.21 mg·L^-1 respectively. (5) Electrochemical behavior ofα-mangostin andγ-mangostin on the glassy carbon electrode was studied. A novel differential pulse voltammetry for the simultaneous determination ofα-mangostin andγ-mangostin in the mixture was established. The corresponding peak currents were proportional to the concentration within 5.0×10^-6-2.0×10^-4mol·L^-1 forα-mangostin, and within 2.0×10^-5-6.0×10^-4mol·L^-1 forγ-mangostin. The limit detection was 1.7×10^-6mol·L^-1 forα-mangostin, and 7.5×10^-6mol·L^-1 forγ-mangostin respectively.(6) The inclusion complexes ofα-mangostin-β-cyclodextrin andγ-mangostin-β-cyclodextrin were characterized by UV absorption spectrometry and IR spectrometry. The stoichiometry and formation constants ofβ-cyclodextrin inclusion complexes withα-mangostin andγ-mangostin were evaluted by UV spectral analysis. The experimental results showed that the molar ratios of inclusion complexes ofβ-cyclodextrin toα-mangostin orγ-mangostin both are 2:1, the inclusion equilibrium constants are 7.57×10⁴L²Â·mol^-2 and 9.23×10⁶L·mol^-2.