(227f) Deep Lignomic Profiling of Byproducts From Extractive Ammonia Fiber Expansion (EA) Pretreatments of Grasses

A. Daniel Jones, Departments of Biochemistry and Molecular Biology and Chemistry, DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI

Deep lignomic profiling of byproducts from extractive ammonia fiber expansion (EA) pretreatments of grasses.  A. Daniel Jones^1,2,3, Afrand Kamali-Sarvestani^1,3, Leonardo da Costa Sousa^1,4, Margaret Magyar ^1,4, Vijay Bokade^1,4, Venkatesh Balan^1,4, and Bruce E. Dale^1,4

(1) DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI

(2) Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI

(3) Department of Chemistry, Michigan State University, East Lansing, MI

(4) Biomass Conversion Research Lab, Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI

Thermochemical pretreatments of lignocellulosic biomass improve digestibility of glycopolymers, but often yield substantial amounts of lignin-like polyphenolic substances that are potential inhibitors of downstream processing.  Opportunities to convert those compounds derived from grasses into high-value chemicals have yet to be fully explored, in part because only a small fraction of pretreatment byproducts have been characterized.  Our recent efforts have employed ultrahigh performance liquid chromatography (UHPLC) separations combined with tandem mass spectrometry on a quadrupole time-of-flight (QTof) mass spectrometer for comprehensive and non-targeted profiling of compounds derived from extractive ammonia fiber expansion (EA) pretreatments of several grasses (corn stover, switchgrass, Miscanthus, wheat straw, and rice straw).  Automated feature recognition data processing demonstrated the presence of several hundred phenolic substances derived from each grass species.  Accurate molecular masses were used to assign elemental formulas for each compound, and tandem mass spectra provided information useful for assigning compounds to structural classes including oligolignols and flavonolignans.  Both qualitative and quantitative differences in byproduct composition were observed in comparisons of the five grasses, and numerous nitrogen-containing compounds were observed, indicative of sinks for ammonia during pretreatment.  We anticipate that this chemical information will help guide further utilization of lignin-like substances generated in biorefineries.