Signalling and Bioactive Metabolites from sp. RK44.

remains one of the prolific sources of structural diversity, and a reservoir to mine for novel natural products. Continued screening for new Streptomyces strains in our laboratory led to the isolation of sp. RK44 from the underexplored areas of Kintampo waterfalls, Ghana, Africa. Preliminary screening of the metabolites from this strain resulted in the characterization of a new 2-alkyl-4-hydroxymethylfuran carboxamide (AHFA) together with five known compounds, cyclo-(L-Pro-Gly) , cyclo-(L-Pro-L-Phe) , cyclo-(L-Pro-L-Val) , cyclo-(L-Leu-Hyp) , and deferoxamine E AHFA , a methylenomycin (MMF) homolog exhibited anti-proliferative activity (EC = 89.6 µM) against melanoma A2058 cell lines. This activity, albeit weak is the first report amongst MMFs. Furthermore, the putative biosynthetic gene cluster () was identified for the biosynthesis of AHFA . DFO-E displayed potent anti-plasmodial activity (IC = 1.08µM) against 3D7. High-resolution electrospray ionization mass spectrometry (HR ESIMS) and molecular network assisted the targeted-isolation process, and tentatively identified six AHFA analogues, - and six siderophores -.