Synthesis and spectral characterization of 2,2-diphenylethyl glucosinolate and HPLC-based reaction progress curve data for the enzymatic hydrolysis of glucosinolates by Sinapis alba myrosinase

The data presented in this article are related to the research article, “HPLC-based enzyme kinetics assay for glucosinolate hydrolysis facilitate analysis of systems with both multiple reaction products and thermal enzyme denaturation” (C.K. Klingaman, M.J. Wagner, J.R. Brown, J.B. Klecker, E.H. Pauley, C.J. Noldner, J.R. Mays,) [1]. This data article describes (1) the synthesis and spectral characterization data of a non-natural glucosinolate analogue, 2,2-diphenylethyl glucosinolate, (2) HPLC standardization data for glucosinolate, isothiocyanate, nitrile, and amine analytes, (3) reaction progress curve data for enzymatic hydrolysis reactions with variable substrate concentration, enzyme concentration, buffer pH, and temperature, and (4) normalized initial velocities of hydrolysis/formation for analytes. These data provide a comprehensive description of the enzyme-catalyzed hydrolysis of 2,2-diphenylethyl glucosinolate (5) and glucotropaeolin (6) under widely varied conditions.


Value of the data
The experimental methods and characterization of 2,2-diphenylethyl glucosinolate and intermediates could be useful toward preparation of synthetic glucosinolates.
HPLC standardization of glucosinolate, isothiocyanate, nitrile, and amine analytes could be useful toward individuals analyzing these compounds.
Complete reaction progress curve datasets for enzymatic hydrolysis reactions conducted with variable experimental conditions provide a comprehensive dataset for this type of enzymatic transformation.
Tables of normalized velocities of hydrolysis and product formation provide a complete, quantitative perspective of these enzymatic reactions.

Data
This article describes the synthesis and characterization data of the non-natural glucosinolate, 2,2diphenylethyl glucosinolate (5), and data related to the kinetic analysis of this compound and glucotropaeolin (6) with Sinapis alba myrosinase. This body of data is related to the methodological innovations and enzymological studies described in the related article, "HPLC-based kinetics assay facilitates analysis of systems with multiple reactions components and thermal enzyme denaturation" [1]; to improve clarity, compound numbering from the related article has been retained.
The data presented in Figs. 1-9 describe the standardization of enzyme and analytes. Reaction progress curve data is provided for experiments evaluating the effects of variable substrate concentration (Figs. 10-13, [Myr] ¼ 8.83 U ml À 1 ), variable enzyme concentration (Fig. 14

General synthetic information
Synthetic reactions were performed using commercial reagents and materials under inert conditions, unless otherwise specified.

Synthesis of 2,2-diphenylethyl glucosinolate
Glucosinolate 5 was prepared from its corresponding alcohol (14) using the aldoxime method previously employed by our group (Scheme 2) [2,4,6]. Reagent 15 was prepared in high yield for minimal cost [7] and its use in the conversion of 14 to 16 was both high yielding and easy to purify. Condensation of aldehyde 16 with hydroxylamine afforded oxime 17 in high yield [6,8]. Treatment of 17 with N-chlorosuccinimide formed an intermediate oximyl chloride, which was immediately coupled to 2,3,4,6-tetra-O-acetyl-1-thio-β-D-glucose (18) to provide scaffold 19. Sulfonation of 19 was accomplished with sulfur trioxide pyridine complex to afford intermediate 20, which was deprotected via Zempelen O-deacetylation to provide glucosinolate 5 in high yield.

Standardization
The specific activity of commercial Sinapis alba myrosinase was determined using the prescribed method [9]. Each analyte was individually standardized using the previously-described HPLC method [2], with minor modifications appropriate to the current related study [1]. Standard curves representing peak area vs. injection amount were generated for each wavelength of interest.

Generation of reaction progress curves and reaction velocities
Enzymatic hydrolysis reactions of glucosinolates were conducted in aqueous buffer using a modified form of the established protocol [1,2]. The concentration of glucosinolate, concentration of Sinapis alba myrosinase, buffer pH, and incubation temperature were varied for a given experiment, which were conducted in triplicate. Analytes at a given reaction timepoint were separated by HPLC and concentrations were determined from integration of analyte peak areas. Reaction progress curves were fit to the data using a modified form of the Lambert W(x) and were used to calculate initial rates of hydrolysis/formation for each observed analyte [1].