label: UDP-alpha-D-xylose(out) + UDP-alpha-D-glucuronate(in) => UDP-alpha-D-xylose(in) + UDP-alpha-D-glucuronate(out)
label_lc: udp-alpha-d-xylose(out) + udp-alpha-d-glucuronate(in) => udp-alpha-d-xylose(in) + udp-alpha-d-glucuronate(out)