Instructions: Given a title, a list of keywords and main findings, create an abstract for a scientific article. Number the compounds in the abstract.
Title: Configurational assignment of cyclic peroxy metabolites provides an insight into their biosynthesis: isolation of plakortolides, seco-plakortolides, and plakortones from the Australian marine sponge Plakinastrella clathrat. 
Keywords: Australian sponge, relative configurational assignment, spectroscopic analysis, absolute configurations, (1)H NMR analysis, polyketide-derived precursor. 
Main findings: Plakinastrella clathrata produces plakortolide C-H, 6-hydroperoxydienoic acid. 4 seco-plakortolides were isolated from Kitagawia praeruptora. Kitagawia praeruptora produces Praeroside VI, Isofraxidin, Scopoletin. Kitagawia praeruptora produces 12 coumarins.
Abstract: First repeat the request without change, then give your answer.
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