Presentation Title

Investigation of Rhamnus crocea Leaf Extracts and Their Effect on Hermes Copper Butterfly

Faculty Mentor

Dr. Jacqueline Trsichman

Start Date

17-11-2018 10:30 AM

End Date

17-11-2018 10:45 AM

Location

C162

Session

Oral 2

Type of Presentation

Oral Talk

Subject Area

interdisciplinary

Abstract

An endemic Southern California species of butterflies known as the Hermes Copper Butterfly (Lycena hermes) seems to be on a path to become extinct. These butterflies are known to lay their larvae on the host plant known as Spiny Redberry (Rhamnus crocea). These plants are indigenous not only in Southern California, but also in Northern California, which is beyond the range of the Hermes Copper Butterflies. To understand their selective reproductive habits, we examined leaves from a wide range of habitats to determine their chemical composition. By investigating the chemistry of the spiny red berry, we aim to identify major chemical compounds in the leaves which attract the butterflies to lay their larvae in that specific areas. A collection of leaves and berries from 60 locations in Southern California were examined, including both areas where the butterflies laid their eggs and areas where they tend not to spawn. However, the first step in processing these samples is to identify the major components commonly found across the collection. For this study, 100g of dried leaves of Spiny Redberry were extracted and fractionated into a nonpolar and polar fraction. Analysis of the nonpolar fraction by NMR and GCMS showed a major chemical component with a molecular weight of 144 amu. This structure is similar but not identical to tocopherol (vitamin E). Structure elucidation of this component will be discussed. The polar fraction was separated using HPLC, then the major components were further investigated by NMR and LCMS. Once purified and identified, these components will be used as standards in the analysis of the smaller leaf extracts from the 60 areas in the study.

Summary of research results to be presented

From this study, a collection of Spiny Redberry were collected to determine the chemical composition of the leaf and its effect on where the Hermes Copper Butterfly lay their eggs. We were able to fractionate a non-polar and polar fraction from liquid-liquid extraction. Studies thus far, have been focused on the non polar fractions and found one chemical compound that was similar, but not identical to tocopherol (vitamin E). Further structure elucidation will be discussed and examined more in depth by NMR.

The polar leaf extract fraction was fractioned by HPLC, collected into 6 different fractions, and examined by NMR and LCMS. From the 6 different fractions, one fraction was found interesting from NMR. Further collection of the interesting fraction is needed by HPLC to obtain more material to analyze. The main structural composition from the interesting polar leaf extract will be discussed in detail and analyzed by NMR.

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Nov 17th, 10:30 AM Nov 17th, 10:45 AM

Investigation of Rhamnus crocea Leaf Extracts and Their Effect on Hermes Copper Butterfly

C162

An endemic Southern California species of butterflies known as the Hermes Copper Butterfly (Lycena hermes) seems to be on a path to become extinct. These butterflies are known to lay their larvae on the host plant known as Spiny Redberry (Rhamnus crocea). These plants are indigenous not only in Southern California, but also in Northern California, which is beyond the range of the Hermes Copper Butterflies. To understand their selective reproductive habits, we examined leaves from a wide range of habitats to determine their chemical composition. By investigating the chemistry of the spiny red berry, we aim to identify major chemical compounds in the leaves which attract the butterflies to lay their larvae in that specific areas. A collection of leaves and berries from 60 locations in Southern California were examined, including both areas where the butterflies laid their eggs and areas where they tend not to spawn. However, the first step in processing these samples is to identify the major components commonly found across the collection. For this study, 100g of dried leaves of Spiny Redberry were extracted and fractionated into a nonpolar and polar fraction. Analysis of the nonpolar fraction by NMR and GCMS showed a major chemical component with a molecular weight of 144 amu. This structure is similar but not identical to tocopherol (vitamin E). Structure elucidation of this component will be discussed. The polar fraction was separated using HPLC, then the major components were further investigated by NMR and LCMS. Once purified and identified, these components will be used as standards in the analysis of the smaller leaf extracts from the 60 areas in the study.