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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVING CITRUS NUTRITIONAL PROPERTIES AND QUALITY TO BENEFIT HUMAN HEALTH AND ENHANCE CITRUS UTILIZATION

Location: Healthy Processed Foods Research

Title: Pcr Amplification and Cloning of Tyrosine Decarboxylase Involved in Synephrine Biosynthesis in Citrus

Authors
item Bartley, Glenn
item Breksa, Andrew
item Ishida, Betty

Submitted to: New Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 10, 2010
Publication Date: September 1, 2010
Citation: Bartley, G.E., Breksa Iii, A.P., Ishida, B.K. 2010. PCR Amplification and Cloning of Tyrosine Decarboxylase Involved in Synephrine Biosynthesis in Citrus. New Biotechnology. doi:10.1016/j.nbt.2010.04.003.

Interpretive Summary: Synephrine is a vascoconstrictor and bronchiectatic agent and may have promise as an aid to weight management and obesity reduction. Synephrine is structurally similar to the active ingredients of several commercial cold remedies. Some Citrus have been shown to possess high concentrations of synephrine. An enzyme involved in synephrine biosynthesis, tyrosine decarboxylase, is an enzyme that decarboxylates tyrosine to yield CO2 and tyramine. We cloned and sequenced this gene from various synephrine producing and non-producing Citrus species and varieties to determine any correlation with synephrine production. PCR amplification and comparison of DNA sequence indicated DNA sequence differences that may cause non-functional proteins to be produced in some non-synephrine producing Citrus. Synephrine production may be genetically determined in part by the gene for tyrosine decarboxylase.

Technical Abstract: The phenolic amine synephrine is a vascoconstrictor and bronchiectatic agent and may have promise as an aid to weight management and obesity reduction. Synephrine is structurally similar to the active ingredients of several commercial cold remedies. Some Citrus have been shown to possess high concentrations of synephrine. An enzyme involved in synephrine biosynthesis, tyrosine decarboxylase, is a pyridoxal-5'-phosphate (PLP)-dependent enzyme that decarboxylates tyrosine to yield CO2 and tyramine. We PCR screened, cloned and sequenced this gene from various synephrine producing and non-producing Citrus species and varieties to determine if DNA sequence of this gene indicated any correlation with synephrine presence. PCR amplification and comparison of DNA sequence indicated DNA sequence differences that may cause truncated proteins to be produced in some non-synephrine producing Citrus. Synephrine production may be genetically determined in part by the gene for tyrosine decarboxylase.

Last Modified: 8/22/2014
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