Stereochemical Elucidation of New Sagittamides C–F from a Didemnid Ascidian

Sarah C. Lievens; Brandon I. Morinaka; Tadeusz F. Molinski

doi:10.1071/CH10059

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Stereochemical Elucidation of New Sagittamides C–F from a Didemnid Ascidian

Sarah C. Lievens ^A , Brandon I. Morinaka ^B and Tadeusz F. Molinski ^B ^C ^D

+ Author Affiliations

- Author Affiliations

^A Department of Chemistry, University of California, Davis, 1 Shields Avenue, Davis, CA 95616, USA.

^B Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA.

^C Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA.

^D Corresponding author. Email: tmolinski@ucsd.edu

Australian Journal of Chemistry 63(6) 935-941 https://doi.org/10.1071/CH10059
Submitted: 29 January 2010 Accepted: 31 May 2010 Published: 11 June 2010

Abstract

Four new minor congeners, sagittamides C–F, were isolated from an unidentified Didemnid tunicate that previously afforded sagittamides A and B. The structures were determined by interpretation of spectroscopic data, degradation to amino acids, and comparisons with sagittamide A. An unexpected change in relative configuration of the hexacetoxy C5–C10 stereoelement is present in sagittamides D and F. A tentative assignment of configuration was possible through a systematic deduction based on analysis of ¹³C NMR data and symmetry considerations.

Acknowledgements

We are grateful the Federated States of Micronesia for permission to collect in territorial waters and Stam for assistance with collections. We thank J. DeRopp (UC Davis), A. Mrse, and X. Huang (UCSD) for assistance with NMR measurements and Y. X. Su (UCSD) for high-resolution MS measurements. The 500-MHz NMR spectrometers were purchased with funds from US National Science Foundation (CRIF, CHE0741968). This work was supported by grants from the National Institutes of Health, US Public Health Service (CA85602 and CA122256).

References

Stereochemical Elucidation of New Sagittamides C–F from a Didemnid Ascidian

Abstract

Acknowledgements

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