Genipin-crosslinked chitosan hydrogels as biomedical and pharmaceutical aids

Microbial transformation of geniposide in Gardenia jasminoides Ellis into genipin by Penicillium nigricans

Genipin is the bioactive compound of geniposide and a natural cross-linking agent. In order to improve the preparation process of genipin, the hydrolysis of geniposide to genipin by immobilized β-glucosidase in an aqueous-organic two-phase system was studied. β-Glucosidase was immobilized by the crosslinking-embedding method using sodium alginate as the carrier. The optimum reaction temperature, pH value and time were 55 °C, 4.5 and 2.5 h, respectively. To reduce genipin hydrolysis and byproduct production the reaction was carried out in an aqueous-organic two-phase system comprising ethyl acetate and sodium acetate buffer. The product was analyzed by HPLC, UV, IR, and NMR. The yield of genipin was 47.81% and its purity was over 98% (HPLC).

Transformation of geniposide into genipin by immobilized β-glucosidase in a two-phase aqueous-organic system.

One-enzyme catalyzed simultaneous plant cell disruption and conversion of released glycoside to aglycone combined with in situ product separation as green one-pot production of genipin from gardenia fruit

Apodytes dimidiata, belonging to the family Icacinaceae, is used for treating inflammation and various gastrointestinal ailments in Zulu traditional medicine. In the present study, significant cytotoxicity was exhibited by the methanolic extract of the A. dimidiata leaf against various cancer cell lines. The extract was purified partially through silica gel column by successive elution using various solvents of increasing polarity. Among these, the active methanolic fraction was found to be the most cytotoxic with IC50 values ranging from 0.92 to 3.95 µg/mL for Ehrlichʼs ascites carcinoma (a carcinoma cell line), Jurkat (human T lymphocyte cell line), and SK-BR-3 (mammary tumour cell line). The treated cells showed morphological alterations characteristic of apoptosis. Upon oral administration of active methanolic fraction at a dose of 250 mg/kg body weight, the solid tumour volume in mice was significantly reduced to 55.14 % and the life span of the ascites tumour-bearing mice increased to 44.65 % compared to untreated control. The active fraction with Rf value 0.56 was purified from the methanolic fraction by preparative thin-layer chromatography and was subjected to high-performance thin-layer chromatography, high-performance liquid chromatography, liquid chromatography-mass spectrometry, and nuclear magnetic resonance analysis. The iridoid glycoside genipin was identified as the active component.

Evaluation of Cytotoxic and Antitumour Properties of Apodytes dimidiata and Characterisation of the Bioactive Component.

A new method for the simultaneous determination of genooposide and genipin in Gardenia jasminoides Eills by reversed-phase high perfomance liquid chromatography was studied.The method used a YWG-C 18 column,0 05 mol/L di-sodium hydrogen phosphate-methanol(72∶28)as the mobile phase at a flow rate of 1 0 ml/min with detection wavelengty at 240 nm.Retention times and recovery rates for geniposide and genipin were 6 33,9 49 min,and 99 10%,98 28%,respectively.The RSD of the results was 1 05% for geniposide,1 21% for genipin.The method was proved to be simple and reliable.

Wang Yan-lei

Papers

Simultaneous Determination of Geniposide and Genipin in Gardenia Jasminoides Eills by High Performance Liquid Chromatography