label: an alpha-L-rhamnosyl-(1->4)-beta-D-glucuronide => a 4-deoxy-alpha-L-threo-hex-4-enopyranuronoside + L-rhamnopyranose
label_lc: an alpha-l-rhamnosyl-(1->4)-beta-d-glucuronide => a 4-deoxy-alpha-l-threo-hex-4-enopyranuronoside + l-rhamnopyranose