Tea is the most consumed beverage in the world (besides water) and the import value of all tea brought into the United States exceeds $12B annually; however, it is estimated that fewer than 100 acres of Camellia sinensis are planted in the US today. Although Camellia sinensis is a sub-tropical crop, it does grow well in California with extended harvest seasons. In the 1960’s, UC Davis initiated a project to investigate tea production in California and it led to the selection of several tea cultivars well suited for central valley growing. The decades-long study concluded that California grown plants could produce up to one ton of processed (dried) tea per acre, matching tea production rates in China. In spite of these important findings, the study was terminated in the early 1980’s partly due to new trading opportunities with China. Thirty-seven years later, increased tea consumption in the US and increased labor costs in tea growing regions world wide have renewed interest in growing Camellia sinensis in California. Sustainable farming of any crop is of great importance today with much attention focused on controlling phosphorous and nitrogen fertilizers to minimize environmental impact.
Research in the Gervay-Hague laboratory centers on the synthesis of plant-associated glycolipids to enable integrated chemical measurements of microbial biomarkers associated with sustainable propagation and growth of tea in California. Bacterial and fungal species residing in the soil serve important roles in nitrogen fixation, phosphorous uptake and aluminum detoxification. The evanescent nature of chemical exchange and enzyme activity demands high sensitivity detection and special attention to collecting plant/microbial tissues for chemical measurements. To achieve this goal, a team of scientists led by Jacquelyn Gervay-Hague is propagating California tea cultivars in controlled environments. They are establishing standard protocols for extracting metabolites from host tissue and efficient synthetic methods for the preparation of plant and microbial glycolipids are under development to generate chemical measurement databases(1-5). Access to pure glycolipid standards is necessary to fully utilize and integrate mass spectrometry, high performance liquid chromatography, gas chromatography, and nuclear magnetic resonance measurements to track metabolites and determine their origin. Preliminary chemical profiling studies involving host/mammalian tissue interactions have utilized azide/alkyne cycloaddition methods for in vitro metabolic-labeling to enable qualitative and quantitative measurement with femtomolar detection limits (6). Analyses of these data sets have led to the new understanding that microbes acquire sugars, phospholipids and cholesterol from the host, and then assemble these chemical building blocks into various forms of cholesteryl glycosides that are transferred back to the host to allow symbiotic relationships to form. These approaches are now being applied to the study of Camellia sinensis and associated microbes to discover symbiotic relationships that promote plant sustainability.
- Schombs M, Park FE, Du W, Kulkarni SS, Gervay-Hague J. One-pot syntheses of immunostimulatory glycolipids. J Org Chem. 2010;75(15):4891-8. Epub 2010/04/15. doi: 10.1021/jo100366v. PubMed PMID: 20387787; PMCID: 2912955.
- Nguyen HQ, Davis RA, Gervay-Hague J. Synthesis and Structural Characterization of Three Unique Helicobacter pylori α-Cholesteryl Phosphatidyl Glucosides. Angew Chem Int Edit. 2014;126:1-5. doi: 10.1002/ange.201406529.
- Gervay-Hague J. Taming the Reactivity of Glycosyl Iodides To Achieve Stereoselective Glycosidation. Acc Chem Res. 2015. doi: 10.1021/acs.accounts.5b00357. PubMed PMID: 26524481.
- Davis RA, Fettinger JC, Gervay-Hague J. Tandem Glycosyl Iodide Glycosylation and Regioselective Enzymatic Acylation Affords 6-O-Tetradecanoyl-alpha-D-cholesterylglycosides. Journal of Organic Chemistry. 2014;79(17):8447-52. doi: 10.1021/Jo501371h. PubMed PMID: WOS:000341345400072.
- Davis RA, Fettinger JC, Gervay-Hague J. Synthesis of cholesteryl-alpha-D-lactoside via generation and trapping of a stable beta-lactosyl iodide. Tetrahedron Letters. 2015;56(23):3690-4. doi: 10.1016/j.tetlet.2015.05.012. PubMed PMID: WOS:000356544800180.
- Jan H-M, Chen Y-C, Shih Y-Y, Huang Y-C, Tu Z, Ingle AB, Liu S-W, Wu M-S, Gervay-Hague J, Mong K-KT, Chen Y-R, Lin C-H. Metabolic labelling of cholesteryl glucosides in Helicobacter pylori reveals how the uptake of human lipids enhances bacterial virulence. Chem Sci. 2016;7(9):6208-16. doi: 10.1039/C6SC00889E.
Natural Product Isolation and Detection of Glycolipids in Tea
Phospholipid Profiling of Tea Extract
Synthesis of Chemical Probes for Metabolic Studies of Tea