Anti-neuroinflammatory asarone derivatives from the rhizomes of Acorus tatarinowii

Abstract

A novel 7-O-7′ type mesomeric neolignan,meso-asarolignan A (1), six pairs of new neolignan enantiomers, (±)-asarolignan B–G (2a/2b,3a/3b,4–6,7a/7b), along with 16 known analogues (8–23) were isolated from the rhizomes ofAcorus tatarinowii.

Constituents and Activities of Acorus tatarinowii

“…Some lignans and phenylpropanoids were evaluated for anti-neuroinflammatory activities on TNF-α production in LPS-activated BV-2 cells. Asarolignan G, tatarinoid C and (7R*,8S*),-7,8-dihydroxy-asarone exhibited obvious inhibitory effects on the release of TNF-α at a concentration of 50 μM, suggesting the configuration was not critical to the antineuroinflammation activity in that case (Qin et al 2017). Tatarinans T and S delayed the Aβ-induced paralysis in CL4176 transgenic C. elegans model at concentration of 100µM, in which tatarinan S exhibited the higher protective effect, with its PT 50 was 62.3% at 100µM and 30.8% at 10μM, respectively (Luo et al 2016).…”

“…Lu's group also reported other pairs of enantiomers such as (±)-acortatarinowins G~I in which (±)-acortatarinowin G were rare 7,8'-epoxy-8,7'-oxyneolignane (Lu et al 2016). Recently, Qin's group reported identification of (±)-asarolignans B and C, which were the first examples of naturally occurring 7-O-7'-type neolignans, along with another new lignan enantiomers (±)-asarolignan G (Qin et al 2017).…”

“…(-)-Tatarinoid C was a rare trinorlignan firstly reported in 2010 (Tong et al 2010), and enantiomers of which were then separated by chiral HPLC in 2017 (Qin et al 2017). Another novel norlignan without trivial name was reported in 2015 .…”

“…Lignans were also obtained as racemic mixtures or a mesomer in some cases, such as ()-asarolignans D~F as racemates (Qin et al 2017) and meso-asarolignan A as a mesomer.…”

Natural Enantiomers: Occurrence, Biogenesis and Biological Properties

“…Owing to the limited numbers, they have all been put together and are discussed in the current section. Compounds 26 and 27 from Acorus tatarinowii are rare cases of naturally occurring 7,7 -oxyneolignans [28]. The threo-configurations for C-7/C-8 and C-7 /C-8 of 26 were first determined by the large J 7,8 and J 7 ,8 values (both 6.5 Hz), which was further confirmed by single crystal X-ray diffraction analysis, while the abs.…”