Biotransformation of Oleaside A by Cunninghamella echinulata

Abstract

Biotransformation of oleaside A (1) by Cunninghamella echinulata (ACCC 30369) was carried out to afford two products, (6R)-6-hydroxyoleaside A (2) and (7S)-7-hydroxyoleaside A (3). The structures of 2 and 3 were elucidated by extensive NMR analyses and further confirmed by single-crystal X-ray diffraction analysis. We also report herein the X-ray diffraction structure of oleaside A (1) for the first time. Compounds 1 -3 were evaluated for their cytotoxic activities against the A549, HCT116, HepG2, and HL-60 human cancer cell lines.Introduction. -Microbial transformation is an effective tool for the structural modification of natural bioactive compounds. Its application in asymmetric synthesis is increasing due to its versatility and simplicity [1]. A variety of transformations on natural products such as oxidation, reduction, hydrolysis, isomerization, epimerization, rearrangement, d-homoannulation, Michael addition, and reverse aldol reaction have already been performed [2]. Cunninghamella echinulata, a filamentous fungus, is recognized for its potential for steroid hydroxylation and has been noted for its ability to mimic mammalian hepatic metabolism with other substrates [3] [4].Oleaside A (1) is one of the most important cardiac glycosides derived from the Nerium oleander L. Recently, the anticancer effects of cardiac glycosides have been reported [5 -7]. In continuation of our biotransformation studies on the natural anticancer products [8] [9], we now report the characterization of two metabolites of oleaside A (1) in cell suspension of C. echinulata (ACCC 30369). These metabolites were identified as (6R)-6-hydroxyoleaside A (2) and (7S)-7-hydroxyoleaside A (3) by spectroscopic methods. We also report here the X-ray diffraction structure of these three compounds. Compounds 1 -3 (see Fig. 1) were evaluated for their cytotoxic activities against the A549, HCT116, HepG2, and HL-60 human cancer cell lines.

Ultra high performance liquid chromatography with photodiode array detector and quadrupole time‐of‐flight tandem mass spectrometry coupled with discriminant analysis to evaluate Angelicae pubescentis radix from different regions

“…It is important to differentiate daodi medicinal material from adulterations in the market to ensure efficacy and safety. Currently, HPLC, LC–MS, FTIR spectroscopy, and GC × GC–TOF‐MS have been applied to identify traditional Chinese medicines (TCMs) from different production regions . However, deficiencies such as complications in operation, time consumption, and high expense have limited their application.…”

Predicting the Impact of Climate Change on the Future Distribution of Paederus fuscipes Curtis, 1826, in China Based on the MaxEnt Model

“…They have a wide habitat range, often feeding on agricultural pests. Therefore, larvae and pupae of other insects become prey for rove beetles [ 7 ]. P. fuscipes can prey on various agricultural pests, such as aphids, leafhoppers, and planthoppers, and thrip on crops like rice, wheat, cotton, corn, and legumes, playing a significant role in biological pest control [ 8 ].…”

“…Currently, there is relatively little research on P. fuscipes in China. Existing studies mainly focus on its biological characteristics [ 6 ], chemical composition [ 7 ], predatory behavior [ 23 ], and the inhibitory mechanisms of plant essential oils on P. fuscipes [ 24 ]. There is limited research on the potential suitable habitats for P. fuscipes .…”