Additional bioactive guanidine alkaloids from the Mediterranean sponge Crambe crambe

Two-dimensional ultra high pressure liquid chromatography quadrupole/time-of-flight mass spectrometry for semi-targeted natural compounds identification

“…As highlighted in our previous study, a subsequent purification step on a C 6 -phenyl column was necessary to yield pure compounds and to allow the structure elucidation by NMR and MS (Bondu et al, 2012). Our reinvestigation of the extract of C. crambe led to the identification of these major compounds but we were aware that several minor compounds were present but impossible to identify due to the low isolated amounts.…”

“…The molecular formula of compound 1 was determined to be Most of the fragments described above have also been observed for crambescins A1 or A2 that only differed in the length of the alkyl chains (Bondu et al, 2012). These results indicate that the remaining degrees of unsaturation are located on the upper aliphatic chain.…”

“…We recently published the structure elucidation of crambescin derivatives from the marine sponge C. crambe (Bondu et al, 2012). The purification and characterization was carried out using our standard protocol (Cachet et al, 2009;Genta-Jouve and Thomas, 2013): after an organic extraction of the lyophilized material with CH 2 Cl 2 /MeOH (1:1), the extract was first submitted to fractionation by reversed phase (RP) Vacuum Liquid Chromatography (VLC).…”

“…Herein, we report a new UHPLC Â UPLC-QTOF-MS/MS method for semi targeted natural compounds identification produced by the marine sponge Crambe crambe that is known to produce a large diversity of complex and bioactive guanidine alkaloids (Bondu et al, 2012). After interpretation of the MS/MS spectra, we were able to identify seven new compounds belonging to the crambescin family and exhibiting original structural features together with eleven previously known compounds.…”

Syntheses of cyclic guanidine-containing natural products

“…The synthesis of 299 has been achieved by the Snider, 337-340 Roush, 341,342 Uyehara, 343,344 Hassner, 345,346 Asaoka, 347 Cossy, 348 Schmalz, 349 and Livinghouse groups. 350 A series of ptilomycalin congeners have also been discovered and named as crambescidins ( 4 , 4b – g , and 4m , n ), 21,351-356 crambidine ( 300 ), 21 celeromycalin ( 4h ), 357 fromiamycalin ( 4i ), 357 and neofolitispates ( 4j – l ) 358 (Fig. 51).…”