Novel South African Rare Actinomycete <i>Kribbella</i> <i>speibonae</i> Strain SK5: A Prolific Producer of Hydroxamate Siderophores Including New Dehydroxylated Congeners
Kojo Sekyi Acquah,
Denzil R. Beukes,
Digby F. Warner,
Paul R. Meyers,
Suthananda N. Sunassee,
Fleurdeliz Maglangit,
Hai Deng,
Marcel Jaspars,
David W. Gammon
Affiliations
Kojo Sekyi Acquah
Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
Denzil R. Beukes
School of Pharmacy, University of the Western Cape, Bellville 7535, South Africa
Digby F. Warner
SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Observatory 7925, South Africa
Paul R. Meyers
Department of Molecular and Cell Biology, University of Cape Town, Rondebosch 7701, South Africa
Suthananda N. Sunassee
Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
Fleurdeliz Maglangit
College of Science, University of the Philippines Cebu, Lahug, Cebu City 6000, Philippines
Hai Deng
Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE, UK
Marcel Jaspars
Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE, UK
David W. Gammon
Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
In this paper, we report on the chemistry of the rare South African Actinomycete Kribbella speibonae strain SK5, a prolific producer of hydroxamate siderophores and their congeners. Two new analogues, dehydroxylated desferrioxamines, speibonoxamine 1 and desoxy-desferrioxamine D1 2, have been isolated, together with four known hydroxamates, desferrioxamine D1 3, desferrioxamine B 4, desoxy-nocardamine 5 and nocardamine 6, and a diketopiperazine (DKP) 7. The structures of 1–7 were characterized by the analysis of HRESIMS and 1D and 2D NMR data, as well as by comparison with the relevant literature. Three new dehydroxy desferrioxamine derivatives 8–10 were tentatively identified in the molecular network of K. speibonae strain SK5 extracts, and structures were proposed based on their MS/MS fragmentation patterns. A plausible spb biosynthetic pathway was proposed. To the best of our knowledge, this is the first report of the isolation of desferrioxamines from the actinobacterial genus Kribbella.
