(4Z,15Z)-bilirubin IXalpha + UDP-alpha-D-glucuronate => (4Z,15Z)-bilirubin IXalpha C8-beta-D-glucuronoside + UDP
(4z,15z)-bilirubin ixalpha + udp-alpha-d-glucuronate => (4z,15z)-bilirubin ixalpha c8-beta-d-glucuronoside + udp