ABSTRACT
Soybeans offer an abundant source of isoflavones, which confer useful bioactivities when existing in aglycone forms. The conversion of isoflavones into aglycones via fermentation of soybean products is often realized by ß-glucosidase, an enzyme produced by fungi. In this study, a filamentous fungus, Clerodendron cyrtophyllum, was isolated from root of Clerodendron cyrtophyllum Turcz, which was able to produce the highest activity of ß-glucosidase up to 33.72 U/mL at 144 h during fermentation on Potato Dextrose Broth (PDB). The obtained fungus was grown on isoflavones-rich soybean extract to produce genistein and daidzein, achieving the conversion rate of 98.7%. Genistein and daidzein were isolated and purified by column chromatography using hexane/acetone (29:1/1:1), reaching purities of over 90% of total isoflavones, as identified and determined by TLC, LC-MS/MS, and 1H and 13C NMR spectroscopy. These results imply that the isolated P. citrinum is a potential fungal strain for industrial-scale production of genistein and daidzein from isoflavones-containing soybean extracts. These products may serve as potential raw materials for manufacture of functional foods that are based on aglycones.
ABSTRACT
Breast cancer is the most common malignant tumor in women these days accounting for approximately 24% of all cancer. During our screening program searching for cytotoxic materials from natural products, two new symmetric dimers of ent-kaurane diterpenoid, crotonkinensins C (1) and D (2), with connectivity at C-17 were isolated from the leaves of the Vietnamese endemic medicinal plant Croton tonkinensis. Their structures were determined on the basis of physicochemical and spectroscopic data. Compound 2 showed a potent cytotoxic activity against MCF-7, tamoxifen-resistant MCF-7 (MCF-7/TAMR), adriamycin-resistant MCF-7 (MCF-7/ADR), and MDA-MB-231 breast cancer cell lines.
Subject(s)
Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Croton/chemistry , Diterpenes, Kaurane/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Dimerization , Diterpenes, Kaurane/chemistry , Diterpenes, Kaurane/isolation & purification , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Female , Humans , Molecular Structure , Structure-Activity RelationshipABSTRACT
Two new diterpenoids, crotonkinensins A (1) and B (2), were isolated from the leaves of the Vietnamese endemic medicinal plant Croton tonkinensis. Their structures were determined to be 7alpha,10alpha-epoxy-14beta-hydroxygrayanane-1(5),16(17)-dien-2,15-dione (1) and 7alpha,10alpha-epoxy-14beta-hydroxygrayanane-1(2),16(17)-dien-15-one (2) by spectroscopic analysis. Compounds 1 and 2 showed strong anti-inflammatory effects on the LPS-induced COX-2 promoter activity and COX-2 expression in Raw 264.7 cells.
