id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-003318-abs9rvjk	Liu, Ming	The enzymatic biosynthesis of acylated steroidal glycosides and their cytotoxic activity	2018-05-01		.txt	text/plain	7844	459	51	Unexpectedly, in an effort to identify OsSGT1, we found the bacteria lacA gene in lac operon actually encoded an SGA, specifically catalyzing the acetylations of sugar moieties of steroid 17β-glucosides. The two-step process is characterized by EcSGA1-catalyzed regioselective acylations of all hydroxyl groups on the sugar unit of unprotected steroidal glycosides (SGs) in the late stage, thereby significantly streamlining the synthetic route towards ASGs and thus forming four monoacylates. We therefore inferred that testosterone (8) was first glycosylated at the 17β-hydroxyl group by OsSGT1 to form T-17β-G (8a), which was then selectively acetylated at C-6 0 of sugar moiety to yield the 6 0 -AT-17β-G (8b) by a soluble bacterial acetyltransferase ( Supplementary Information Fig. S52) . The optimal pH and temperature of OsSGT1-catalyzed reaction using the cell-free extract of BL21(DE3)[pET28a-OsSGT1þp-Gro7] as the biocatalyst were first determined to be alkaline pH value of 11 and 50 1C, respectively (Supplementary Information Fig. S62 ).	./cache/cord-003318-abs9rvjk.txt	./txt/cord-003318-abs9rvjk.txt