Pipestelides A–C: Cyclodepsipeptides from the Pacific Marine SpongePipestela candelabra

Abstract

Pipestelides A-C (2-4) are three new NRPS-PKS hybrid macrolides containing uncommon moieties, isolated from the Pacific marine sponge Pipestela candelabra. Their structures were elucidated on the basis of spectroscopic data. These cyclodepsipeptides appear to be biosynthetically related to jaspamide (aka jasplakinolide) (1) by chemical modification of the building blocks of the polyketide or peptide chains. Pipestelides A-C (2-4) contain a bromotyrosine [3-amino-3-(bromo-4-hydroxyphenyl)propanoic acid] unit, a polypropionate with a Z double bond, and a 2-hydroxyquinolinone, respectively. Revised chemical shift assignments are provided for the co-isolated known jasplakinolide C(a) (5). In addition, compounds 2 and 3 exhibited cytotoxic activities in the micromolar range.

Marine Indole Alkaloids

“…We will make use of Pelletier’s general definition of 1983, according to which alkaloids are “cyclic organic compounds containing nitrogen in a negative oxidation state which are of limited distribution among living organisms” [ 2 ]. As an additional demarcation against the world of peptides, polypeptidic structures and macrocyclic peptides derived from tryptophan, such as terpeptins [ 3 ] and related structures [ 4 ], milnamides [ 5 , 6 ], diazonamides [ 7 ], lucentamycin B [ 8 ], pipestelides [ 9 ], kahalalides [ 10 , 11 , 12 ], jaspamides [ 13 ], jasplakinolides [ 14 ], etc. , will not be discussed here.…”

Marine natural products

“…The sponge Pipestela candelabra (Guadalcanal, Solomon Is.) contained the mixed NRPS-PKS pipestelides A-C 633-635, which are related to the well known jaspamides 583. 198 | Nat.Prod.…”

Potent Cytotoxic Peptides from the Australian Marine Sponge Pipestela candelabra

“…Chemical investigation of the sponge P . candelabra was first reported in 2012 with the identification of four cyclodepsipeptides, including jaspamide and pipestelides A–C, from a sample collected in the Solomon Islands [3]. However, a different structure class, hemiasterlin and milnamide analogues, was found in this chemical study on the Australian sponge P .…”