Structure elucidation, biogenesis, and bioactivities of acylphloroglucinol-derived meroterpenoid enantiomers from Dryopteris crassirhizoma

Antimicrobial Acylphloroglucinol Meroterpenoids and Acylphloroglucinols from Dryopteris crassirhizoma

“…The trans arrangements of H 3 -14″/H-6″ in 11 and 12 were comfirmed by ROESY correlations of H-7 β ↔ H 3 -14″ and H-7 α ↔ H-6″ in 11 and 12 . The relative configurations of 11 and 12 were furthur supported by meticulous comparison of the NMR data with their similar epimer pairs 10 . As shown in Table 2S , Supporting Information, the comparison of proton and carbon chemical shifts in 11 and 12 with those known analogues, dryoptol G~I (3″ S *,6″ S *,7″ R *-form) and 3″- epi -dryoptol G~I (3″ R *,6″ S *,7″ R *-form), allowed the determination of 11 and 12 as (3″ S *,6″ S *,7″ R *) for 11 and (3″ R *,6″ S *,7″ R *) for 12 .…”

“…In our recent study, variations of proton and carbon chemical shifts around the stereogenic centers at positions remote from each other, were successfully applied to predict the relative configurations of acylphloroglucinol-nerolidol meroterpenoids 10 . It was presumed that the chemical shift variations caused by C-11″ epimerization in acylphloroglucinol-dehydrotheonelline meroterpenoids ( 1 ~ 10 ) may also be utilized for discrimination of epimer pairs.…”

“…After seperation using chiral HPLC ( Fig. 2S , Supporting Information), the NMR data of 13 and 14 were reassigned ( Table 3S , Supporting Information) by comparison of its NMR data with their derivatives from this plant 10 . Therefore, the relative configurations could be assigned as (3″ S *,10″ R *) for 13 and (3″ R *,10″ R *) for 14 .…”

“…Since the nerolidol-based meroterpenoids from this plant are derived from (±)-nerolidol and appears as racemate 10 , biosynthetically, 11 ~ 14 could be characterized as racemates and given the names (±)-dryoptol M, (±)-3″- epi -dryoptol M, (±)-dryoptol N, and (±)-3″- epi -dryoptol N, respectively.…”

“…Its rhizomes (mian ma guan zhong in Chinese) are the ingredients of three Chinese patent medicine products, “lian hua qing wen” ( ) 3 , “kang gan ke li” ( ) 4 , and “compound guanzhong aspirin tablets” ( ) 5 , which have been used to treat respiratory infections in cold and influenza. “Mian ma guan zhong” has been reported to contain acylphloroglucinol derivatives, some of which exhibited antibacterial, antiplatelet, and antiviral activities including influenza viruses H1N1, H5N1 and H7N9 6 , 7 , 8 , 9 , 10 . Most recently, a series of unusual acylphloroglucinol-nerolidol meroterpenoids 5 , 10 and β -tocopherol derivatives 11 have been found from “mian ma guan zhong”.…”