Linear peptide alkaloids from the sponge Clionacelata (Grant). Celenamides C and D

Abstract

. Can. J. Chem. 58,2121Chem. 58, (1980. Celenam~des C (7) and D (8), two novel alkaloids closely related to peptide alkaloids found in higher plants, have been isolated as their penta (12) and nonacetyl (13) derivatives, respectively, from acetylated extracts of the sponge Cliona celata (Grant). The structure elucidation of 7 and 8 is described. On a isolt deux nouveaux alcaloi'des les ctlenamides C (7) et D (8) qui s'apparentent beaucoup aux alcaloi'des peptidiques que I'on trouve dans les plantes superieures. On les obtient sous forme de dtrives penta (12) et non acttyles (13) a partir des extraits acetyles de I'tponge Cliona celata (Grant). On decrit la determination de la structure des composes 7 et 8.

Synthesis of Z‐N‐Alkenylformamides

“…[23,24] The mixture was then carried through various steps without separation until the final step (Scheme 1). Hydrolysis of the olefinic ester to the acid (5, 6) in 90-97% yield followed by mixed anhydride formation and azide addition gave the acylazides (7,8) in 80-81% yield. Subsequent thermal Curtius rearrangement to give the isocyanates (9, 10), followed by reduction with lithium tri-tert-butoxy-aluminohydride, gave the mixture of N-alkenylformamides (11,12) in 77% yield.…”

Molecular Networking-Guided Isolation of New Etzionin-Type Diketopiperazine Hydroxamates from the Persian Gulf Sponge Cliona celata

“…Autophagymodulating aminosteroids clionamines A-D were isolated from C. celata sourced from South Africa [31]. There have been several reports on peptide-type compounds of the genus Cliona [10][11][12][13][14]. The first peptidic compounds tetraacetyl clionamide and clionamide with antibacterial activity were reported in the late 1970s from Canadian C. celata specimens [32].…”

“…The first peptidic compounds tetraacetyl clionamide and clionamide with antibacterial activity were reported in the late 1970s from Canadian C. celata specimens [32]. Further linear peptide alkaloids celenamides A-D were subsequently obtained from the same sponge [12,14]. The tripeptide alkaloid celenamide E was obtained from C. chilensis and showed moderate antibiotic activity against Gram-positive bacteria (S. aureus, Micrococcus luteus, Bacillus subtilis, and Enterococcus faecalis) [13].…”

“…Chemically, the genus has been little studied, but the few studies performed on this genus so far have revealed the presence of diverse natural product classes, such as steroids, alkaloids, and peptides [7][8][9][10]. Peptidic constituents of the genus Cliona include clionamide, the major metabolite of C. celata; tetraacetyl clionamide; celenamides A, B, and E; and cyclo-(L-Pro-L-Tyr) diketopiperazine (DKP) [10][11][12][13][14], reported from Cliona sponges collected from various geographical regions, such as Argentina, Canada, Spain, Morocco, and Thailand [7][8][9][10][11][12][13][14]. Only two Cliona species, namely C. celata and C. vastifica, have been reported from the fauna of the Persian Gulf [15], but they have not been subjected to any chemical or bioactivity study so far.…”

Unravelling the Anti-Inflammatory and Antioxidant Potential of the Marine Sponge Cliona celata from the Portuguese Coastline

“…A future approach for further chemical investigation should be conducted by LC-HRMS/MS and NMR. Throughout the years, several compounds have been isolated from C. celata, namely clionamide A-D, celenamide A-D, and acetyl homoagmatine, but currently, no reported studies have investigated the antioxidant or anti-inflammatory activities of these compounds [21,[40][41][42][43][44][45].…”