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 eggs 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 redberry, we aim to identify major chemical compounds in the leaves which attract the butterflies to lay their eggs 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.

Investigation of Rhamnus crocea leaf extract effect on Hermes copper butterfly

2019 Spring National Meeting

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