Details

Autor(en) / Beteiligte

• He, Haiyin
• Wu, ShiBiao
• Wahome, Paul G
• Bertin, Matthew J
• Pedone, Anna C
• Beauchesne, Kevin R
• Moeller, Peter D. R
• Carter, Guy T

Titel

Microcystins Containing Doubly Homologated Tyrosine Residues from a Microcystis aeruginosa Bloom: Structures and Cytotoxicity

Ist Teil von

• Journal of natural products (Washington, D.C.), 2018-06, Vol.81 (6), p.1368-1375

Ort / Verlag

United States: American Chemical Society and American Society of Pharmacognosy

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Four new microcystin congeners are described including the first three examples of microcystins containing the rare doubly homologated tyrosine residue 2-amino-5-(4-hydroxyphenyl)­pentanoic acid (Ahppa) (1–4). Large-scale harvesting and biomass processing allowed the isolation of substantial quantities of these compounds, thus enabling complete structure determination by NMR as well as cytotoxicity evaluation against selected cancer cell lines. The new Ahppa-toxins all incorporate Ahppa residues at the 2-position, and one of these also has a second Ahppa at position 4. The two most lipophilic Ahppa-containing microcystins showed 10-fold greater cytotoxic potency against human tumor cell lines (A549 and HCT-116) compared to microcystin-LR (5). The presence of an Ahppa residue in microcystin congeners is difficult to ascertain by MS methods alone, due to the lack of characteristic fragment ions derived from the doubly homologated side chain. Owing to their unexpected cytotoxic potency, the potential impact of the compounds on human health should be further evaluated.