Chloroform → HCID 101636766, compound

Participants

Reaction Steps

36 g of crude extract were applied to a 3.5×49 cm silica gel column, and eluted successively with chloroform and a chloroform:methanol mixture in which the methanol concentration gradually rose to 5% (final composition 95:5). In this way, 14.6 g of semi-pure compound were obtained, and this was applied to a silica gel (200-300 mesh) column 6×31 cm in size, and was then eluted with a benzene:ethyl acetate mixture gradually increasing the ethyl acetate concentration to 60% (final composition 4:6). This resulted in fraction A in an amount of about 0.19 g and fraction B in an amount of about 1.2 g. For further purification, fraction A was applied to a 1.4×80 cm Sephadex LH 20® column and was eluted with methanol, resulting in 142 mg of a compound which was purified by preparative thin-layer chromatography (silica gel plates of thickness 0.5 mm) in a mixture of chloroform:methanol (95:5). This resulted in 96 mg of a pure compound which was identified as the known antibiotic naphthomycin A. Then a 6×30 cm silica gel H® column (without binder) was charged, as a chromatography column, with fraction B, and elution was carried out with a mixture of chloroform and methanol (96:4). This resulted in 650 mg of a semi-pure substance which was purified by a preparative thin-layer chromatography (silica gel plates 1 mm thick) in a mixture of chloroform and methanol (95:5), and was then recrystallized from a petroleum ether:benzene:ethyl acetate mixture, this resulting in naphthomycin H in an amount of 120 mg.

Provenance & Evidence