Four New Lignan Glycosides from Osmanthus fragransLour. var. aurantiacusMakino

Abstract

Four new tetrahydrofuranoid lignan glycosides, (7S,8R,7′R,8′S)‐4,9,4′,7′‐tetrahydroxy‐3,3′‐dimethoxy‐7,9′‐epoxylignan 9‐O‐β‐D‐glucopyranoside (2), (7R,8S,7′S,8′R)‐4,9,4′,7′‐tetrahydroxy‐3,3′‐dimethoxy‐7,9′‐epoxylignan 9‐O‐β‐D‐glucopyranoside (3), (7R,8S,7′R,8′S)‐4,9,4′,9′‐tetrahydroxy‐3,3′‐dimethoxy‐7,7′‐epoxylignan 9‐O‐β‐D‐glucopyranoside (4), and rel‐(7R,8S,7′S,8′R)‐4,9,4′,9′‐tetrahydroxy‐3,3′‐dimethoxy‐7,7′‐epoxylignan 9‐O‐β‐D‐glucopyranoside (5), and ten known lignan glycosides, 1 and 6–14, were isolated from the leaves of Osmanthus fragrans Lour. var. aurantiacus Makino. Their structures were established on the basis of spectral and chemical studies.

Stereochemical assignment of five new lignan glycosides from Viscum album by NMR study combined with CD spectroscopy

“…During the analysis of the stereochemistry of compounds 1 and 2 as well as other compounds with similar structures such as 7 R ,8 R ,8' S ‐aketrilignoside B, (7 S ,8 R ,7' R ,8' S )‐4,9,4',7'‐tetrahydroxy‐3,3'‐dimethoxy‐7,9'‐epoxylignan 9‐ O ‐β‐D‐glucopyranoside, and 7 S ,7' S ,8 R ,8' R ‐icariol A 2 , it was found that the stereochemistry of C‐7 or C‐7' in monofuranoid lignans affects the signal of CD at around 210 nm. For example, if a CD spectrum has a positive signal at 210 nm, the configurations at C‐7 or C‐7' of lignan were determined to be R .…”

“…The positive Cotton effect [Δε: + 1.65 (216)] (Fig. ) in the CD spectrum of 3 proved the configuration at C‐7 to be S by comparing it with those of 7 R lignan glycosides: 7 R ,8 R ,8' S ‐aketrilignoside B [Δε: – 14.0 (215)] (7 R ,8 S ,7' S ,8' R )‐4,9,4',7'‐tetrahydroxy‐3,3'‐dimethoxy‐7,9'‐epoxylignan 9‐ O ‐β‐D‐glucopyranoside [Δε:–12.9 (205), –2.5 (234)], and 7 S lignan glycosides: (7 S ,8 R ,7' R ,8'S)‐4,9,4'‐trihydroxy‐3,5,3',5',7'‐pentamethoxy‐7,9'‐epoxylignan 9‐ O ‐β‐D‐glucopyranoside [Δε: + 15.2 (206), + 3.5 (235)], alangilignoside C [Δε: + 11.1 (211), ‐1.14 (244)] . The small coupling constant J 7‐8 = 3.6 Hz between H‐7 and H‐8 confirmed cis configuration of the substituted groups at C‐7 and C‐8, and it was further proved by strong NOE correlation between H‐7 (δ H 5.13) and H‐8 (δ H 2.52).…”

Bioactive Constituents from the Aerial Parts of Lippia triphylla

“…The coupling constant of H-7′ ( J = 7.5 Hz) in 1 suggested an antiperiplanar orientation of H-7′ and H-8′. On the other hand, the CD spectrum of 1 (Δε: −121.7 (201 nm), −5.9 (228 nm)) was very similar to that of (7 R ,8 S ,7′ S ,8′ R )-4,9,4′,7′-tetrahydroxy-3,3′-dimethoxy-7,9′-epoxylignan 9- O -β- d -glucopyranoside (Δε: −12.9 (205 nm), −2.5 (234 nm)) [39], which indicated the absolute configuration of 1 was 7 R ,8 S ,7′ S ,8′ R . Furthermore, the NOE correlations between δ H 4.56 (H-7) and δ H 2.40 (H-8′) and 3.75 (H-9a); δ H 1.75 (H-8) and δ H 3.97 (H-7′); and δ H 2.40 (H-8′) and δ H 3.75 (H-9a), 6.64 (H-6′) and 6.76 (H-2′) observed in the NOESY spectrum confirmed the accuracy of configuration analysis.…”

Chemical Constituents and Antibacterial Properties of Indocalamus latifolius McClure Leaves, the Packaging Material for “Zongzi”

“…The six known compounds were identified (Figure 1) as L-phenylalanine ( 1 ) [14], dihydroxymethyl-bis(3,5-dimethoxy-4-hydroxyphenyl) tetrahydrofuran-9- O -β- d -glucopyranoside ( 3 ) [15], rel -(7 R ,8 S ,7′ S ,8′ R )-4,9,4′,9′-tetrahydroxy-3,3′-dimethoxy-7,7′-epoxylignan 9- O- β- d -glucopyranoside ( 4 ) [16], apigenin 6- C- α- l -arabinopyranosyl-8- C- β- d -glucopyranoside ( 5 ) [17], apigenin 7- O ,8- C - di -glucopyranoside ( 6 ) [18], and ( 7S , 8S ) syringylglycerol-8- O -4′-sinapyl ether 9′- O- β- d -glucopyranoside ( 9 ) [19] through comparing their spectroscopic and physical data with those of previous reports.…”