Fig. 4From: Identification of the natural product berberine as an antiviral drugEffect of berberine on the secondary structure of 6-HB structure by CD spectroscopy. a The secondary structure of 6-HB in the absence of berberine displayed a typical helical conformation, while lost α-helical conformation in the presence of berberine. N36 and C34 served as negative controls, C34 + N36 served as a positive control. The molar ratio of N36 and C34 in a sample was 1:1. b Model of interaction of berberine with NHR and CHR helices of gp41. NHR and CHR helices were indicated in light green and orange, respectively. Berberine was abbreviated to acronyms BBRBack to article page