β-Hydroxydihydrochalcone and flavonoid glycosides along with triterpene saponin and sesquiterpene from the herbs ofPimpinella rhodanthaBoiss.

Abstract

A new β-hydroxydihydrochalcone glycoside named ziganin (1) and a new acylated flavonol glycoside named isorhamnetin-3-O-α-L-(2″,3″-di-O-trans-coumaroyl)-rhamnopyranoside) (2), along with two known flavonoid glycosides, a β-hydroxydihydrochalcone glycoside, a hydroxybenzoic acid derivative, a trinorguaiane type sesquiterpenoid, a triterpenic saponin and a polyol were isolated from the herbs of Pimpinella rhodantha Boiss. Their structures were elucidated on the basis of spectroscopic analyses including 1D-and 2D-NMR, UV, IR, CD, ESI-MS, APCI-MS, HR-ESI-MS techniques. The isolated compounds were evaluated for their antioxidant capacity through the DPPH free-radical scavenging assay and ferrous ion-chelating power test.

Bioassay-Guided Isolation of New Flavonoid Glycosides from Platanus × acerifolia Leaves and Their Staphylococcus aureus Inhibitory Effects

“…The 1 H NMR spectrum ( Table 1 ) displayed three coupled aromatic proton signals at δ H 7.42 (1H, dd, J = 2.0, 8.4 Hz, H-6′), δ H 7.38 (1H, d, J = 2.0 Hz, H-2′), and δ H 6.96 (1H, d, J = 8.4 Hz, H-5′) attributed to a 1,3,4-trisubstituted benzene ring, along with two meta -coupled doublets at δ H 6.39 (1H, d, J = 2.0, H-8) and δ H 6.21 (1H, d, J = 2.0, H-6). Undoubtedly, the data above delineated a quercetin backbone [ 29 , 30 , 31 ]. In addition, the 1 H- 1 H COSY motif ( Figure 2 ) of H-1″/H-2″/H-3″/H-4″/H-5″/H 3 -6″ in conjunction with the 13 C ( Table 1 ) and HSQC NMR experiments ( Figure S3 ) revealed the presence of an α-rhamnose moiety [ 29 , 32 ], which was found to locate at C-3 due to the key HMBC correlation from H-1″ to C-3 (δ C 135.56) ( Figure 2 ).…”

“…Undoubtedly, the data above delineated a quercetin backbone [ 29 , 30 , 31 ]. In addition, the 1 H- 1 H COSY motif ( Figure 2 ) of H-1″/H-2″/H-3″/H-4″/H-5″/H 3 -6″ in conjunction with the 13 C ( Table 1 ) and HSQC NMR experiments ( Figure S3 ) revealed the presence of an α-rhamnose moiety [ 29 , 32 ], which was found to locate at C-3 due to the key HMBC correlation from H-1″ to C-3 (δ C 135.56) ( Figure 2 ). Besides, two p -coumarate units were constructed owing to the observation of two sets of well-resolved proton signals: δ H 7.47 (2H, br d, J = 8.4 Hz, H-2‴, 6‴), δ H 6.80 (2H, br d, J = 8.4 Hz, H-3‴, 5‴), δ H 7.61 (1H, d, J = 15.6 Hz, H-7‴), and δ H 6.31 (1H, d, J = 15.6 Hz, H-8‴) accounting for a (E)-p-coumarate unit; δ H 7.69 (2H, br d, J = 8.4 Hz, H-2′′′′, 6′′′′) and δ H 6.77 (2H, br d, J = 8.4 Hz, H-3′′′′, 5′′′′), together with δ H 6.88 (1H, d, J = 12.8 Hz, H-7′′′′) and δ H 5.73 (1H, d, J = 12.8 Hz, H-8′′′′), arising from a ( Z )- p -coumaryl moiety.…”

A New Β-Hydroxydihydrochalcone from Tephrosia Uniflora, and the Revision of Three Β-Hydroxydihydrochalcones to Flavanones

“…Some compounds that have originally been reported as β-hydroxydihydrochalcones were later revised to flavanones [17]. A review of the recent literature suggests that further flavanones may have mistakenly been reported as β-hydroxydihydrochalcones [22][23][24]. To clarify the spectroscopic difference between these two compound classes, herein we compare the 1 H and 13 C NMR data of the β-hydroxydihydrochalcones (S)-elatadihydrochalcone-2'-methyl ether (1), (S)-elatadihydrochalcone (3) [17], ziganin (5) [23], 3-(S)-hydroxy-3-phenyl-1-(2',4',6'-trihydroxyphenyl)propan-1-one (6) [22], and balanochalcone (7) [24] with those of the corresponding flavanones (5a, 6a and 7a).…”

“…A review of the recent literature suggests that further flavanones may have mistakenly been reported as β-hydroxydihydrochalcones [22][23][24]. To clarify the spectroscopic difference between these two compound classes, herein we compare the 1 H and 13 C NMR data of the β-hydroxydihydrochalcones (S)-elatadihydrochalcone-2'-methyl ether (1), (S)-elatadihydrochalcone (3) [17], ziganin (5) [23], 3-(S)-hydroxy-3-phenyl-1-(2',4',6'-trihydroxyphenyl)propan-1-one (6) [22], and balanochalcone (7) [24] with those of the corresponding flavanones (5a, 6a and 7a). We further give the predicted chemical shifts of the β-hydroxydihydrochalcone and flavanone skeletons, and note that the chemical shifts of the αand β-protons (Table 2), and of the corresponding carbon atoms (Table 3) provide a helpful tool for differentiation between these compound classes.…”

Structures, Occurrences and Biosynthesis of 11,12,13-Tri-nor-Sesquiterpenes, an Intriguing Class of Bioactive Metabolites

“…Since then, compound 86 has been extracted from several Pimpinella species [ 42 , 43 , 45 , 47 , 52 , 252 , 253 , 254 ] and Dictamnus species [ 255 , 256 , 257 ].…”