Chemical Investigation of the Antarctic Marine Invertebrates Austrodoris kerguelenensis & Dendrilla membranosa and the Antarctic Red Alga Gigartina skottsbergii
The marine realm and, in particular, the Antarctic benthos is largely unexplored and understudied. The chemical investigation reported herein reveals not only the biodiversity, but how that biodiversity manifests remarkable chemical diversity. In our continuing study of the nudibranch Austrodoris ke...
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ftunisfloridatam:oai:digitalcommons.usf.edu:etd-4431 2023-06-11T04:04:53+02:00 Chemical Investigation of the Antarctic Marine Invertebrates Austrodoris kerguelenensis & Dendrilla membranosa and the Antarctic Red Alga Gigartina skottsbergii Maschek, John Alan 2011-01-01T08:00:00Z application/pdf https://digitalcommons.usf.edu/etd/3236 https://digitalcommons.usf.edu/context/etd/article/4431/viewcontent/Maschek_usf_0206D_10557.pdf unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/etd/3236 https://digitalcommons.usf.edu/context/etd/article/4431/viewcontent/Maschek_usf_0206D_10557.pdf default USF Tampa Graduate Theses and Dissertations organic chemistry natural products nudibranch sponge red alga palmadorin lectin bioassay American Studies Arts and Humanities dissertation 2011 ftunisfloridatam 2023-05-04T18:02:10Z The marine realm and, in particular, the Antarctic benthos is largely unexplored and understudied. The chemical investigation reported herein reveals not only the biodiversity, but how that biodiversity manifests remarkable chemical diversity. In our continuing study of the nudibranch Austrodoris kerguelenensis, we have isolated a diverse suite of diterpenoid glyceride esters, palmadorins D - S (2.32 - 2.47), one of which is the first reported halogenated diterpene from a dorid nudibranch. Utilizing genomic data from collaborators, we have investigated the chemical diversity from phylogenetically unique specimens collected in close proximity to one another. Chemical groupings based on comparison of LC/MS metabolite fingerprints from individual organisms correlated well to the genetic data. Our research shows that A. kerguelenensis specimens from the same phylogroups elaborate near identical metabolite profiles to each other, but distinct from other phylogroups. Dendrilla membranosa is a dominant demosponge that prior studies have shown is rarely preyed upon and deters feeding against amphipods, the principal mesograzers of the Western Antarctic Peninsula. To assess the defensive nature of the pure compounds, artificial food pellets spiked with membranolides were evaluated in a feeding assay against the omnivorous amphipod Gondogeneia antarctica whereby only artificial pellets containing membranolide exhibited significant feeding deterrence. The research reported herein demonstrates that membranolides C and D were originally misassigned. Reevaluation of new extracts evolved additional fused furan membranolides G and H, and allowed for complete characterization of the four epimers. Extraction of sponge in CD3OD resulted in incorporation of a deuterated methyl group into fragment ions as evidenced from LC/MS chromatograms. Further chemical investigation of D. membranosa without the use of methanol revealed that these non-natural products arise from aplysulphurin, a known compound originally isolated from the sponge ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctic Peninsula Antarctica Digital Commons University of South Florida (USF) Antarctic The Antarctic Antarctic Peninsula |
institution |
Open Polar |
collection |
Digital Commons University of South Florida (USF) |
op_collection_id |
ftunisfloridatam |
language |
unknown |
topic |
organic chemistry natural products nudibranch sponge red alga palmadorin lectin bioassay American Studies Arts and Humanities |
spellingShingle |
organic chemistry natural products nudibranch sponge red alga palmadorin lectin bioassay American Studies Arts and Humanities Maschek, John Alan Chemical Investigation of the Antarctic Marine Invertebrates Austrodoris kerguelenensis & Dendrilla membranosa and the Antarctic Red Alga Gigartina skottsbergii |
topic_facet |
organic chemistry natural products nudibranch sponge red alga palmadorin lectin bioassay American Studies Arts and Humanities |
description |
The marine realm and, in particular, the Antarctic benthos is largely unexplored and understudied. The chemical investigation reported herein reveals not only the biodiversity, but how that biodiversity manifests remarkable chemical diversity. In our continuing study of the nudibranch Austrodoris kerguelenensis, we have isolated a diverse suite of diterpenoid glyceride esters, palmadorins D - S (2.32 - 2.47), one of which is the first reported halogenated diterpene from a dorid nudibranch. Utilizing genomic data from collaborators, we have investigated the chemical diversity from phylogenetically unique specimens collected in close proximity to one another. Chemical groupings based on comparison of LC/MS metabolite fingerprints from individual organisms correlated well to the genetic data. Our research shows that A. kerguelenensis specimens from the same phylogroups elaborate near identical metabolite profiles to each other, but distinct from other phylogroups. Dendrilla membranosa is a dominant demosponge that prior studies have shown is rarely preyed upon and deters feeding against amphipods, the principal mesograzers of the Western Antarctic Peninsula. To assess the defensive nature of the pure compounds, artificial food pellets spiked with membranolides were evaluated in a feeding assay against the omnivorous amphipod Gondogeneia antarctica whereby only artificial pellets containing membranolide exhibited significant feeding deterrence. The research reported herein demonstrates that membranolides C and D were originally misassigned. Reevaluation of new extracts evolved additional fused furan membranolides G and H, and allowed for complete characterization of the four epimers. Extraction of sponge in CD3OD resulted in incorporation of a deuterated methyl group into fragment ions as evidenced from LC/MS chromatograms. Further chemical investigation of D. membranosa without the use of methanol revealed that these non-natural products arise from aplysulphurin, a known compound originally isolated from the sponge ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Maschek, John Alan |
author_facet |
Maschek, John Alan |
author_sort |
Maschek, John Alan |
title |
Chemical Investigation of the Antarctic Marine Invertebrates Austrodoris kerguelenensis & Dendrilla membranosa and the Antarctic Red Alga Gigartina skottsbergii |
title_short |
Chemical Investigation of the Antarctic Marine Invertebrates Austrodoris kerguelenensis & Dendrilla membranosa and the Antarctic Red Alga Gigartina skottsbergii |
title_full |
Chemical Investigation of the Antarctic Marine Invertebrates Austrodoris kerguelenensis & Dendrilla membranosa and the Antarctic Red Alga Gigartina skottsbergii |
title_fullStr |
Chemical Investigation of the Antarctic Marine Invertebrates Austrodoris kerguelenensis & Dendrilla membranosa and the Antarctic Red Alga Gigartina skottsbergii |
title_full_unstemmed |
Chemical Investigation of the Antarctic Marine Invertebrates Austrodoris kerguelenensis & Dendrilla membranosa and the Antarctic Red Alga Gigartina skottsbergii |
title_sort |
chemical investigation of the antarctic marine invertebrates austrodoris kerguelenensis & dendrilla membranosa and the antarctic red alga gigartina skottsbergii |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2011 |
url |
https://digitalcommons.usf.edu/etd/3236 https://digitalcommons.usf.edu/context/etd/article/4431/viewcontent/Maschek_usf_0206D_10557.pdf |
geographic |
Antarctic The Antarctic Antarctic Peninsula |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica |
op_source |
USF Tampa Graduate Theses and Dissertations |
op_relation |
https://digitalcommons.usf.edu/etd/3236 https://digitalcommons.usf.edu/context/etd/article/4431/viewcontent/Maschek_usf_0206D_10557.pdf |
op_rights |
default |
_version_ |
1768391555902603264 |