10.26686/wgtn.12509912.v1 Joe Bracegirdle Joe Bracegirdle Z Sohail Z Sohail Michael Fairhurst Michael Fairhurst Monica Gerth Monica Gerth Giuseppe Zuccarello Giuseppe Zuccarello M Ali Hashmi M Ali Hashmi Robert Keyzers Robert Keyzers Costatone C—A new halogenated monoterpene from the New Zealand red alga plocamium angustum Open Access Te Herenga Waka-Victoria University of Wellington 2020 halogenated monoterpene Plocamium angustum costatone Mosher's analysis DFT ECD Mosher’s analysis Plocamium Staphylococcus aureus Staphylococcus epidermidis Hydrocarbons, Halogenated Monoterpenes Plant Extracts Anti-Bacterial Agents Magnetic Resonance Spectroscopy Microbial Sensitivity Tests Molecular Structure New Zealand Medicinal & Biomolecular Chemistry Physical Chemistry (incl. Structural) Pharmacology and Pharmaceutical Sciences 2020-06-18 21:00:14 Journal contribution https://openaccess.wgtn.ac.nz/articles/journal_contribution/Costatone_C_A_new_halogenated_monoterpene_from_the_New_Zealand_red_alga_plocamium_angustum/12509912 © 2019 by the authors Red algae of the genus Plocamium have been a rich source of halogenated monoterpenes. Herein, a new cyclic monoterpene, costatone C (7), was isolated from the extract of P. angustum collected in New Zealand, along with the previously reported (1E,5Z)-1,6-dichloro-2-methylhepta-1,5-dien-3-ol (8). Elucidation of the planar structure of 7 was achieved through conventional NMR and (−)-HR-APCI-MS techniques, and the absolute configuration by comparison of experimental and DFT-calculated ECD spectra. The absolute configuration of 8 was determined using Mosher’s method. Compound 7 showed mild antibacterial activity against Staphylococcus aureus and S. epidermidis. The state of Plocamium taxonomy and its implications upon natural product distributions, especially across samples from specimens collected in different countries, is also discussed.