Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/3/2015
Publication Date: 5/31/2015
Citation: Harden, L.A., Pan, J., Takeoka, G.R. 2015. Detection of methylenecyclopropylglycine (MCPG) and hypoglycin A in litchi fruit (abstract). 63rd ASMS Conference on Mass Spectrometry and Allied Topic, St. Louis, MO. May 31-June 4, 2015.
Technical Abstract: Introduction Methylenecyclopropylalanine (hypoglycin A), an unusual amino acid, is known to occur in the fruit of Blighia sapida Koenig. Known as ackee fruit, this member of the family Sapindaceae (soapberry family) is associated with a hypoglycemic malady, and Jamaican vomiting sickness. Another fruit of the soapberry family, Litchi chinensis, is known to produce a similar compound, methylenecyclopropylglycine (MCPG), which has also been associated with hypoglycemic activity. As such, methods of detecting MCPG and hypoglycin A in fruits are of interest. Methods Litchi fruits were dissected to separate exocarp, aril, and seed. Samples were prepared by homogenization, followed by centrifugation of a subsample of the homogenate. The supernatant was washed with hexane, filtered (0.45 'm) and diluted (10X) prior to HPLC-MS and MS-MS analyses. Components were separated with Intrada amino acid column at a flow rate of 500 'L/min with a gradient of acetonitrile (0.1% formic acid) and [(20:80) acetonitrile: 100 mM ammonium formate]. MS and MS-MS data were collection on a Thermo Orbitrap Elite, in positive ion mode using narrow range full scan and SRM methods to target MCPG and hypoglycin A. Preliminary Results/Abstract Both MCPG and hypoglycin A were detected in extracts from litchi fruit. Masses were measured within 5 ppm of the calculated mass of each compound by using a narrow mass range scan at 30,000 mass resolution. SRM scans produced CID fragments which could be logically assigned to the compound structures, and were within 5 ppm agreement with their calculated masses. The HPLC method allowed separation of MCPG and hypoglycin A in under 9 min. Novel Aspect Determination of both hypoglycin A and MCPG in litchi fruit. Use of mixed phase amino acid column for rapid analysis.