A tetrachloro polyketide hexahydro-1H-isoindolone, muironolide A, from the marine sponge Phorbas sp. natural products at the nanomole scale.
Muironolide A, a new chemical entity with an unprecedented chlorinated hexahydro-1H-isoindolone skeleton, was isolated in only 90 microg yield from the same marine sponge, Phorbas sp. that also provided phorboxazoles A and B. The structure was solved by interpretation of NMR data obtained at 600 MHz with a 1.7 mm cryo-microprobe in combination with FTMS, exciton coupled CD, and stereochemical correlation with authentic standards prepared by Reformatsky reaction of (-)-(1R,2S)-2-chloro-1-cyclopropanecarboxaldehyde. The absolute configuration of the chlorocyclopropane ring in 1 is opposite to that of co-occurring phorbasides A-F. Muironolide A is the first described macrolide bearing an esterified trichloromethyl carbinol, and may be produced by a cyanobacterium that also makes phorbasides.
Dalisay
Doralyn S
DS
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
Morinaka
Brandon I
BI
Skepper
Colin K
CK
Molinski
Tadeusz F
TF
D000818:Animals; D054833:Isoindoles / Q000737:chemistry* / Q000302:isolation & purification; D018942:Macrolides / Q000737:chemistry* / Q000302:isolation & purification; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D011161:Porifera / Q000737:chemistry*
C110621:Isoindol-1-one; D054833:Isoindoles; D018942:Macrolides