Biotransformation of steriodal saponins in Dioscorea zingiberensis C. H. Wright to diosgenin by Trichoderma harzianum

Abstract

Diosgenin is an important starting material in the steroidal hormone industry. Traditionally, diosgenin is mainly produced by acid hydrolysis of Dioscorea zingiberensis C. H. Wright (DZW) tubers. This method yields numerous byproducts that can cause serious pollution. In this study, diosgenin was obtained by biotransformation of steroidal saponins in DZW afforded by Trichoderma harzianum CGMCC 2979. The medium was optimized for maximum diosgenin production. The addition of phosphate buffer, surfactant Tween-85, and Fe(2+) increased the yield of diosgenin by 50.28%, 33.35%, and 22.07%, respectively. The optimum medium obtained by response surface methodology was composed of 60 mmol l(-1) phosphate buffer, 0.07% (w/v) Tween-85, and 0.93 mmol l(-1) Fe(2+). Under these conditions, a maximum diosgenin yield of 30.05 +/- 0.59 mg g(-1) was achieved, which was slightly higher than that obtained from traditional acid hydrolysis. By hydrolyzing the un-transformed steroidal saponins after biotransformation, the total diosgenin yield increased by 35% compared to traditional method. Moreover, chemical oxygen demand and residual reduced sugar in the wastewater produced by this integrated process were only 3.72% and 0.3%, respectively, that of the traditional acid hydrolysis method.

Deltonin Isolated from Dioscorea zingiberensis Inhibits Cancer Cell Growth through Inducing Mitochondrial Apoptosis and Suppressing Akt and Mitogen Activated Protein Kinase Signals

“…6) Steroidal saponins are the major active components of DZW, and Deltonin, diosgenin-3-O-b -D-glucopyranosyl(1→4)-[a -L-rhamnopyranosyl(1→2)]-b-D-glucopyranoside, is one of the main constituents of these steroidal saponins. [7][8][9] In our previous study, we found that Deltonin was effective in the treatment of cancer cells and was able to induce cancer cell apoptosis both in vitro and in vivo. 10) In the present study, we investigated the anticancer effect of Deltonin on a panel of cancer cell lines and analyzed its mechanism in C26 cells.…”

Microwave-Assisted Three-Liquid-Phase Extraction of Diosgenin and Steroidal Saponins from Fermentation Broth of <i>Dioscorea zingiberensis</i> C. H. Wright

“…The fermentation broth was obtained from the biotransformation of DZW dried root powder under optimized conditions, as described previously [8]. T. harzianum is preserved at the China General…”

“…Four hundred microlitres each of the middle and bottom phases were added to two volumes of anhydrous methanol, and the mixture was vigorously mixed by inversion and then centrifuged at 12,000 rpm for 15 min. The supernatant was collected and analysed by analytical HPLC [8]. The samples were analysed with a Waters 600E multi-solvent delivery system (Agilent, America) equipped with a Sunfire C18 column, 44% A→75% A; 14-15 min, 75% A→91% A; and 15-32 min, 91% A.…”

“…Alternatively, microbial transformation is environmentally friendly and requires mild conditions [5]. Recently, the microbial transformation of diosgenin from the corresponding glycosidal form of steroidal saponin in plant tissues has been proposed as an alternative to traditional acid hydrolysis, which generates serious pollution [6][7][8]. Due to its high selectivity and mild reaction conditions, microbial transformation provides a high yield of diosgenin.…”

Direct Biotransformation of Dioscin into Diosgenin in Rhizome of Dioscorea zingiberensis by Penicillium dioscin

“…However, to our knowledge, there were very few reports on screening of microorganism of highly efficient biotransformation of dioscin to diosgenin and no reports on direct biotransformation of RDZ, which was simple and more practical. Several literatures reported biotransformation of extracted steroidal saponins to diosgenin, but of low biotransformation rate [13][14][15]; furthermore, extraction of dioscin is relatively of high cost, which makes it less applicable in the biotransformation procedure. So related researches should be focused on screening of microorganism species with high activity and developing a highly efficient biotransformation system.…”