Synthesis and anti‐HIV activity of 6‐amino‐6‐deoxy‐(1→3)‐β‐ D ‐curdlan sulfate

Abstract 6‐Amino‐6‐deoxy‐(1→3)‐β‐D‐curdlan sulfate was synthesized in three steps. First, curdlan was azidized by lithium azide (LiN3) and carbon tetrabromide (CBr4) with triphenylphosphine (Ph3P) in dimethylformamide (DMF). Second, the azido group was reduced to an amino group with sodium borohydride (NaBH4) in dimethyl sulfoxide (DMSO) to afford 6‐amino‐6‐deoxy‐(1→3)‐β‐D‐curdlan. Third, sulfation of the amino‐group‐containing curdlan with a sulfur trioxide‐pyridine complex produced a 6‐amino‐6‐deoxy‐(1→3)‐β‐D‐curdlan sufate exhibiting high anti‐HIV (human immunodeficiency virus) activity (EC50 = 0.912 µg/ml) and low cytotoxicity (CC50 = 2512 µg/ml).