Studies of marine natural products in Tasmania
Creators: name: Jongaramruong, J
Publisher: name: University Of Tasmania
Year: 2023

description: Isolation and structure elucidation of secondary metabolites from two red algae, Plocamium cartilagineum and Laurencia filiformis, together with the sea hare Aplysia parvula are discussed. In addition, chemical relationships between the sea hare Aplysia parvula and the red alga Laurencia filiformis were also investigated. Some details of studies from an ascidian Polyandrocarpa lapidosa, a bryozoan Watersipora lapidosa, a bryozoan Bugula dentata and its associated nudibranch Tambje verconis, as well as a bryozoan Cribricellina ruin and its associated pycnogonid Pseudopallene ambigua were included. More over, a study of brown algae, Bellotia eriophorum, Sporochnus species and Perithalia caudata was described. Two new acyclic polyhalogenated monoterpenes, (3E,7E)-8-bromo-(2E)- chloromethylene-(5R*,6R*)-dichloro-6-methyloctadien- 1-al ( 1) and (1Z,3E,7E)-8,9- dibromo-(1Z,5R*,6R*,9)-tetrachloro-6-methyoctatriene (2), as well as two known acyclic polyhalogenated monoterpenes (3-4), were isolated and identified from the red alga Plocamium cartilagineum. The structures were established by spectroscopic techniques (\\(^1\\)H, \\(^{13}\\)C NMR, DEPT, HMQC, HMBC, COSY, NOESY experiments, and mass spectrometry). [Structural formulas not included in this metadata but are included in the PDF] One new chamigrene, 5-acetoxy-2,10-dibromo-3-chloro-7,8-epoxy-˜í¬±-chamigrene (5), the known chamigrene, 2,10-dibromo-3-chloro-7-chamigrene (6), deoxyprepacifenol (7), and pacifenol (8) were isolated from both the red alga Laurencia filiformis and the sea hare Aplysia parvula. On the other hand the known purple pigment, aplysioviolin (9) and the known fimbrolide (10) were isolated only from the sea hare Aplysia parvula. The fimbrolide was previously isolated from Delisea elegans and Delisea pulchra (a synonym for Delisea fimbriata). Pentadecanal (11) and its aldol product, namely (E)-2-tridecy1-2-heptadec-2-enal (12), were only separated from the red alga Laurencia filiformis. The structure of aplysioviolin has been revised in this study and pentadecanal was separated from the red seaweed Laurencia sp. for the first time. [Structural formulas not included] Homarine (13) was isolated from the ascidian Polyandrocarpa lapidosa. The structure of homarine was confirmed by synthesis. [Structural formulas not included] Two known metabolites, 1,8-dihydroxyanthraquinone (14) and 5,7-dihydroxy- I-methoxycarbony1-6-oxo-6H-anthra[1,9-bc]thiophene (15) were separated from the bryozoan Watersipora subtorquata. [Structural formulas not included] An investigation of the bryozoan Bugula dentata and its associated nudibranch Tambje verconis showed that eight known compounds, tamjamines A (16), B (17), C (18), D (19), E (20), G (21), H (22), and J (23) were found from both the bryozoan and the nudibranch. [Structural formulas not included] 16 R=R'=R\=H 17 R=Br R'=R\"=H 18 R=H R'=CH\\(_2\\)CH(CH\\(_3\\))\\(_2\\) R\"=H 19 R=H R'=CH\\(_2\\)CH(CH\\(_3\\))\\(_{2'}\\) R\"=Br 20 R=H R'=CH\\(_2\\)CH\\(_{3'}\\) R\"=Br 21 R=Br R'=CH\\(_2\\)CH\\(_{3'}\\) R\"=H 22 R=Br R'=CH\\(_2\\)CH\\(_2\\)CH\\(_{3'}\\) R\"=H 23 R=Br R'=CH\\(_2\\)CH(CH\\(_3\\))CH\\(_2\\)CH\\(_{3'}\\) R\"=H A study of brown algae Bellotia eriophorum Sporochnus comosus Sporochnus species and Perithalia caudata showed a variable percentage content of two known compounds (24-25) which were previously isolated from Perithalia caudata. [Structural formulas not included] A preliminary study of secondary metabolites from the bryozoan Cribricellina rufa and its associated pycnogonid Pseudopallene ambigua revealed that 13‚ÄövÑvÆcarboline metabolites were presented in the bryozoan Cribricellina rufa and the pycnogonid Pseudopallene ambigua by gas chromatography mass spectrometry."