Dihydrochalcones from the Leaves of Pieris japonica

Abstract

Six new dihydrochalcones, 3-hydroxyasebotin (5), asebogenin 2'-O-beta-D-ribohexo-3-ulopyranoside (6), 2' '-acetylasebotin (7), 3',4,5'-trihydroxy-4'-methoxydihydrochalcone 3',5'-di-O-beta-D-glucopyranoside (8), and pierotins A (9) and B (10), along with four known dihydrochalcones, phloretin (1), phlorizin (2), asebogenin (3), and asebotin (4), were isolated from the leaves of Pieris japonica. Their structures were elucidated on the basis of spectroscopic analysis including HMQC, HMBC, NOESY, and X-ray crystal diffraction. Compounds 1, 3-5, and 7-10 inhibited the proliferation of murine B cells and compounds 5 and 10 inhibited the proliferation of murine T cells in vitro significantly.

Iridoid Glycosides from the Leaves of Sambucus ebulus

“…The coupling constants J 1′,2′ ) 7.9 Hz and J 1′′,2′′ ) 1.3 Hz indicated a glycosidic linkage of the glucopyranosyl sugar moiety and an R glycosidic linkage of the 4′′-Oacetylrhamnopyranosyl residue. 16,19 Acid hydrolysis followed by derivatization with L-cysteine methyl ester hydrochloride confirmed the absolute configurations of the sugar moieties as D-glucose and L-rhamnose as determined by GC analysis. Thus The HSQC spectrum also exhibited one anomeric signal (δ C 100.1, δ H 4.90), revealing the presence of a sugar moiety at C-11 (δ 68.6) as determined by analysis of the HMBC spectrum.…”

“…The HRFABMS spectrum displayed a quasimolecular ion at m/z 1 H and 13 C NMR Data for Compounds 4-6 (C 5 D 5 N) 16 . Thus, compounds 4 and 3 were isomers.…”

Dietary chalcones with chemopreventive and chemotherapeutic potential

“…Likewise, dihydrochalcone asebogenin (27), which is found in several plants, including Piper aduncum, and used as a condiment and for cocoa flavoring, downregulated the proliferation of murine B cells [180].…”

Pierisformotoxins A – D, Polyesterified Grayanane Diterpenoids from Pieris formosa and Their cAMP‐Decreasing Activities

“…Comparison of 1D-NMR data suggested that CH 2 (15) in the latter compound was replaced by an O-bearing CH group, with an additional OH group at C(15) in 4. This deduction was confirmed by HMBCs of HÀC (15) with C(7), C(8), C(13), C (14), and Me (17), and of HÀC (9), HÀC (14), and Me (17) The known compounds were determined as pierisoid A [8], pierisoid B [8], secorhodomollolide D [7], pierisformosin B [4], asebotoxin IV [24], asebotoxin V [24], asebotoxin VIII [25], grayanotoxin-I [26], grayanotoxin-III [27], 5,6-acetonylgrayanotoxin-I [28], grayanotoxin XXII [16], oleanolic acid [29], ursolic acid [30], bsitosterol [31], bayogenin [32], arjunolic acid [33], (2S,3R)-ent-catechin [34], 2',4-dihydroxy-4'-methoxy-6'-O-b-glucopyranoside dihydrochalcone [35], asebotin [36], bis-8,8'-catechinylmethane [37] [41], and 2,6-dimethoxy-4-hydroxyphenol 1-O-b-d-glucopyranoside [42] by comparison of their spectral data with literature values.…”