The use of natural products as chemotherapeutic agents is well established; however, many of these are associated with undesirable side effects, including high toxicity and instability. Furthermore, the development of drug resistant cancers makes the search for new anticancer lead compounds a priority. In this study, the extraction of an sp.
View Article and Find Full Text PDFFive known (1, 2, 4, 6 and 7) halogenated monoterpenes together with 1Z,3R∗,4S∗,5E,7Z)-1-bromo-3,4,8-trichloro-7-(dichloromethyl)-3-methylocta-1,5,7-triene (3) and (3R∗,4S∗)-3,4,6,7-tetrachloro-3,7-dimethyl-octen-1-ene (5) were isolated from the red macroalga Plocamium suhrii and their structures deduced from their spectroscopic data. The seven compounds from P. suhrii together with five related compounds from Plocamium cornutum have been evaluated for their cytotoxic effects on an esophageal cancer cell line (WHCO1).
View Article and Find Full Text PDFThe synthesis of phosphorous oxide triazatetrabenzcorroles (TBC) tetra- (9, 11) or octa- (13) substituted on the ring with halogenated functional groups is reported. The complexes are not aggregated in dimethylsulfoxide (DMSO) and show solubility in solvents such as pyridine. The Q band absorption spectra of the complexes are red-shifted compared to unsubstituted PTBC.
View Article and Find Full Text PDFFour new halogenated monoterpene aldehydes (1-4) have been isolated from the South African marine red alga Plocamium corallorhiza, along with the known compounds 4,6-dibromo-1,1-dichloro-3,7-dimethyl-2E,7-octadiene (5) and 1,4,8-tribromo-3,7-dichloro-3,7-dimethyl-1E,5E-octadiene (10). The structures of the new compounds were determined by interpretation of their spectroscopic data and synthesis and mass spectrometric analysis of their pentafluorobenzyloxime (PFBO) derivatives.
View Article and Find Full Text PDFThis review presents the structure, biological activity, biosynthetic studies and, where applicable, references to syntheses of 81 marine alkaloids containing either tetra-, hexa- or octa-hydrogenated variants of pyrrolo[4,3,2-de]quinoline, pyrrolo[4,3,2-de]pyrrolo[2,3-h]quinoline and pyrido[2,3-h]pyrrolo[4,3,2-de]quinoline core skeletons. The literature describing the isolation of pyrroloiminoquinones, and related metabolites, from marine sponges is littered with taxonomic inconsistencies and recent efforts to clarify the taxonomy of the sponges that produce this group of metabolites are discussed.
View Article and Find Full Text PDFAn examination of organic extracts of four new species of South African latrunculid sponges, Tsitsikamma pedunculata, T. favus, Latrunculia bellae, and Strongylodesma algoaensis, yielded 13 known and eight new pyrroloiminoquinone alkaloids, 3-dihydro-7,8-dehydrodiscorhabdin C (4), 14-bromo-3-dihydro-7,8-dehydrodiscorhabdin C (5), discorhabdin V (6), 14-bromo-1-hydroxydiscorhabdin V (7), tsitsikammamine A N-18 oxime (10), tsitsikammamine B N-18 oxime (11), 1-methoxydiscorhabdin D (12), and 1-aminodiscorhabdin D (13). Standard spectroscopic methods provided the structures of the pyrroloiminoquinone metabolites, while chiral GC-MS analysis of the acylated ozonolysis products of 21 confirmed the stereochemistry of the l-histidine residue in this compound.
View Article and Find Full Text PDFUltraviolet (UV) light is known to induce the generation of free radicals in biological tissues such as skin. Of these free radicals, the O2-. and particularly the.
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