Aster plants produce and release a chemical known as germacrene D, which comes in (+) and (-) forms called enantiomers that differ in terms of how they interact with light. Some insects are able to distinguish between the two enantiomers using their olfactory receptor neuron, and a great deal of evidence indicates that female pearl crescent butterflies (Phyciodes tharos) prefer to lay their eggs on the underside of aster leaves containing higher amounts of (-)-germacrene D. Amy Klockowski '09 (Rome, N.Y.) is working with Silas D. Childs Professor of Chemistry Robin Kinnel to show unambiguously that it is (-)-germacrene D and not (+)-germacrene D that acts as the chemical stimulus for egg laying in pearl crescents.
This is Klockowski's third summer collaborating with Kinnel on this butterfly project. She extracted (-)-germacrene D from aster plants two summers ago and synthesized allene and cryptone – two precursors to making germacrene D – last summer. This summer, Klockowski plans on using these precursors to create optically pure (+)-germacrene D. Synthesizing (+)-germacrene involves carrying out a series of several chemical reactions, including one important photochemical reaction in which ultraviolet light is used to combine cryptone with allene. Because (+)-germacrene is not as prevalent as (-)-germacrene, extracting it from asters is difficult. Thus, if Klockowski successfully synthesizes (+)-germacrene in the lab, then she will be able to obtain enough of the chemical to study how pearl crescent butterflies react to the two different forms of germacrene D. For this study, she will use GC linked electroantennaographic detection (GC-EAD), which sends electrical signals through the antennas to test the olfactory receptor neurons.
A chemistry major and history minor, Klockowski plans on continuing her current summer research project for her senior thesis. She says she enjoys the project because it provides a mixture of biology and chemistry and it has real world applications to ecology. Klockowski is vice president of Students for International Public Health Awareness (SFIPHA), plays on the women's rugby team, volunteers with Operation Smile, and works in Café Opus and as an orientation leader. She hopes to attend dental school next fall.
-- by Nick Berry '09
This is Klockowski's third summer collaborating with Kinnel on this butterfly project. She extracted (-)-germacrene D from aster plants two summers ago and synthesized allene and cryptone – two precursors to making germacrene D – last summer. This summer, Klockowski plans on using these precursors to create optically pure (+)-germacrene D. Synthesizing (+)-germacrene involves carrying out a series of several chemical reactions, including one important photochemical reaction in which ultraviolet light is used to combine cryptone with allene. Because (+)-germacrene is not as prevalent as (-)-germacrene, extracting it from asters is difficult. Thus, if Klockowski successfully synthesizes (+)-germacrene in the lab, then she will be able to obtain enough of the chemical to study how pearl crescent butterflies react to the two different forms of germacrene D. For this study, she will use GC linked electroantennaographic detection (GC-EAD), which sends electrical signals through the antennas to test the olfactory receptor neurons.
A chemistry major and history minor, Klockowski plans on continuing her current summer research project for her senior thesis. She says she enjoys the project because it provides a mixture of biology and chemistry and it has real world applications to ecology. Klockowski is vice president of Students for International Public Health Awareness (SFIPHA), plays on the women's rugby team, volunteers with Operation Smile, and works in Café Opus and as an orientation leader. She hopes to attend dental school next fall.
-- by Nick Berry '09
