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A new furofuran lignan, styraxlignolide B (1), and four new dibenzyl-γ-butyrolactone lignans, styraxlignolides C−F (2−5), were isolated from the EtOAc-soluble fraction of stem bark of Styrax japonica. Known compounds, taraxerol (6), syringin (7), and (−)-pinoresinol glucoside (8), were also obtained. The structures of styraxligonolides B−F were determined as 2α-(4‘-hydroxy-3‘-methoxyphenyl)-6α-(3‘ ‘,4‘ ‘-methylenedioxyphenyl)-8-oxo-3,7-dioxabicyclo[3.3.0]octane 4‘-O-(β-d-glucopyranoside) (1), (2S,3S)-2α-(3‘ ‘-hydroxy-4‘ ‘-methoxybenzyl)-3β-(4‘-hydroxy-3‘-methoxybenzyl)-γ-butyrolactone 4‘-O-(β-d-glucopyranoside) (2), (2S,3S)-2α-(4‘ ‘-hydroxy-3‘ ‘-methoxybenzyl)-3β-(4‘-hydroxy-3‘-methoxybenzyl)-γ-butyrolactone 4‘-O-(β-d-glucopyranoside) (3), (2S,3S)-2α-(4‘ ‘-hydroxy-3‘ ‘-methoxybenzyl)-3β-(4‘-hydroxy-3‘-methoxybenzyl)-γ-butyrolactone 4‘ ‘-O-(β-d-glucopyranoside) (4), and (2S,3S)-2α-(3‘ ‘,4‘ ‘-dimethoxybenzyl)-3β-(4‘-hydroxy-3‘-methoxybenzyl)-γ-butyrolactone 4‘-O-(β-d-glucopyranoside) (5) by spectroscopic means including 2D NMR. Compounds 1−8 were tested in vitro for antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Styraxlignolide C (2), styraxlignolide D (3), styraxlignolide E (4), and (−)-pinoresinol glucoside (8) exhibited weak radical-scavenging activity in the DPPH assay, with IC50 values of 380, 278, 194, and 260 μM, respectively.

The authors propose an efficient traceback scheme for the parallel hardware implementation of the Viterbi algorithm. Compared to the conventional Viterbi algorithm, where output is selected arbitrarily when multiple survivor paths exist, the proposed algorithm decides decoding output by analysing the survivor paths of consecutive tracebacks. Experimental results show that the proposed algorithm exhibits improved error-correction capability compared to the existing algorithms.