Antioxidant and tyrosinase inhibitory constituents from a desugared sugar cane extract, a byproduct of sugar production.

Recycling agricultural resources has become an important issue worldwide promoting the economical value of agricultural production processes. Desugared sugar cane extract (DSE) from Saccharum officinarum is a byproduct obtained during sugar production. Two new neolignan glucosides, saccharnan A (1) and saccharnan B (2), together with 10 known phenolics (3-12) were isolated from DSE, and their structures were elucidated on the basis of NMR spectral analysis. Compounds 3, 4, 8, and 9 showed good activity against DPPH radical (IC(50) ≤ 51.20 μM) and compounds 3-8 and 12 exhibited strong ABTS(+) free radical scavenging activity (IC(50) ≤ 51.57 μM) compared to those of the positive controls, ascorbic acid and Trolox. Moreover, compounds 7 and 12 acted as potent tyrosinase inhibitors (IC(50) ≤ 42.59 μM) compared to the positive control arbutin. Our results highlighted the economical value of recycling DSE for the future development of natural antioxidants and/or tyrosinase inhibitors.