Nocarimidazoles C and D, antimicrobial alkanoylimidazoles from a coral-derived actinomycete Kocuria sp.: application of ¹J_C,H coupling constants for the unequivocal determination of substituted imidazoles and stereochemical diversity of anteisoalkyl chains in microbial metabolites

• Md. Rokon Ul Karim,
• Enjuro Harunari,
• Amit Raj Sharma,
• Naoya Oku,
• Kazuaki Akasaka,
• Daisuke Urabe,
• Mada Triandala Sibero and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 2719–2727, doi:10.3762/bjoc.16.222

• of the genus Kocuria, isolated from a stony coral Mycedium sp., led to the identification of two new alkanoylimidazoles, nocarimidazoles C (1) and D (2) as well as three known congeners, nocarimidazoles A (3) and B (4) and bulbimidazole A (5). Structure analysis of 1 and 2 by NMR and MS revealed that

• MIC ranges of 6.25–25 μg/mL. Keywords: 1JC,H; alkanoylimidazoles; anteiso; Kocuria; nocarimidazole; Introduction The phylum Actinobacteria contains bacterial genera most prolific as producers of novel natural products with high structural diversity, unique modes of action, and potent bioactivities

• siderophores and modified peptides, are known from Kocuria and Micrococcus [19][20]. In our continuing investigation on secondary metabolites from marine bacteria, five alkanoylimidazoles were obtained from the culture extract of a Kocuria strain isolated from a stony coral. Alkanoylimidazoles are a new and