Acetophenone Diglycosides from Erythroxylum cambodianum

Abstract

Erythroxylum cambodianum PIERRE (Erythroxylaceae, Thai name: Huun-Hai) is a shrub that grows up to 1.5 m high, distributed in Northeastern Thailand. It is used in Thai traditional medicine for anti-fever purposes, as well as an anti-inflammatory agent. In the course of our continuing studies on Thai medicinal plants, the constituents of this plant were investigated. To the best of our knowledge, no phytochemical study has been carried out on this species. However, previous phytochemical investigation of plants in this genus showed the presence of alkaloids, flavonoids and triterpenoids.1-4) The present paper deals with the isolation and structural determination of seven compounds, including two new acetophenone glycosides (1, 2), two known flavans (3, 4), one known flavonol glycoside (5), and two known megastigmane glucosides (6, 7) from the aerial portion of this plant. Results and DiscussionThe methanolic extract was suspended in H 2 O and defatted with Et 2 O. The n-BuOH soluble fraction was subjected to a Diaion HP-20 column, using H 2 O, 50% aqueous MeOH, MeOH and Me 2 CO successively. The portion eluted with MeOH was repeatedly chromatographed on columns of silica gel, RP-18, and preparative HPLC-ODS to afford 7 compounds. Five were identified as the known compounds (ϩ)-and citroside A (7), 8) by comparison of physical data with values reported in the literature and from spectroscopic evidence.Erythroxyloside A (1) was isolated as an amorphous powder, and determined to be C 20 H 28 O 13 by negative high-resolution (HR)-FAB mass spectrometry. The 9) The remaining carbon signals belonged to the sugar part, and were identified as b-apiofuranosyl-(1→6)-b-glucopyranosyl unit by comparing chemical shifts with the reported data. 9)All protonated carbons were assigned by the results from heteronuclear single quantum coherence (HSQC) and heteronuclear multiple-bond connectivity (HMBC) spectra. Enzymatic hydrolysis of 1 with crude hesperidinase gave 2,4-dihydroxy-6-methoxy-acetophenone (1a), identified by 1 H-and 13 C-NMR spectral analysis, 10) in addition to the sugar fraction from the aqueous layer. The stereochemistry of an apiose could be assigned as D-form by the coupling of H-5Љ at d H 3.54, which showed the magnetic equivalent.11) The absolute configuration of a glucose was determined as D-form by treating the sugar fraction with L-cysteine methyl ester in pyridine to provide the thiazolidine derivatives of sugars, and then comparing the Rf values with the standard sample of thiazolidine derivative of D-glucose [methyl 2-(D-gluco-pentahydroxypentyl)-thiazolidine-4(R)-carboxylate], which was prepared by the previously reported method (see Experimental).12,13) Two spots of the derivative from D-glucose were found on TLC (Rf: 0.42, 0.49), due to the C-2 epimers of thiazolidine derivatives. The location of the sugar moiety was Two new acetophenone diglycosides, erythroxylosides A and B, were isolated from the aerial portion of Erythroxylum cambodianum together with (؉)-catechin, (؊)-epicatechin, quercetin 3-O-rut...

Phenolic Compounds from Artemisia iwayomogi and Their Effects on Osteoblastic MC3T3-E1 Cells

“…Compound 4 was obtained as a white amorphous powder; the molecular formula was determined to be C 26 Additionally, twelve known phenolic compounds were identified as scopoletin (1), 15) scopolin (2), 16) 12) myrciaphenone A (5), 17) 2,4-dihydroxy-6-methoxy acetophenone 4-O-b-D-glucoside (6), 16) 2,4-dihydroxy-6-methoxyacetopbenone (7), 18) erythroxyloside B (8), 19) coniferin (9), 20) citrusin C (10), 20) tachioside (11), 20) benzoic acid (12), 20) and caffeic acid methyl ester (13), 21) by comparing their physical and spectral data with those found in the literatures. The current study represents the first time these compounds have been isolated from the Artemisia species.…”

Dolichandroside, a new phenolic triglycoside from Dolichandrone serrulata (DC.) Seem.

“…Phytochemical investigation has not been carried out on this species. The present paper deals with the isolation of a new phenolic triglycoside (6), along with six known phenolic glycosides (1)(2)(3)(4)(5)7) and a known iridoid glucoside (8) from the branches of this plant.…”

Glycosides from the Aerial Parts of <i>Patrinia villosa</i>

“…Patriviloside 1 (1) was isolated as a yellow amorphous powder and its molecular formula was established as C 36 …”

“…The BuOH extract was subjected to sequential column chromatography over silica gel, Sephadex LH-20 and RP-18 gel to yield two new flavonoid glycosides, patrivilosides 1 (1) and 2 (2), a new iridoid glycoside, patrinovalerosidate (3), and two new saponins, patrinovilosides A (4) and B (5), along with six known compounds that included three iridoid glycosides, loganin (6), 23) valerosidate (7), 24,25) and loganic acid (11), 23) and three flavonoid glycosides, kaempferol 3-O-4‴-acetylrhamninoside (8), 26) catharticin (9), 26) and kaempferol 3-O-rhamninoside (10). 8,26) Known compounds were identified by detailed 1D-and 2D-NMR analyses, comparison of their FAB-MS and spectral data with those reported in literature.Patriviloside 1 (1) was isolated as a yellow amorphous powder and its molecular formula was established as C 36 …”

“…Patriviloside 1 (1) was isolated as a yellow amorphous powder and its molecular formula was established as C 36 + , which showed the presence of a linear sugar chain, and the sugar sequence appeared to be that of Rha−Rha−Gal. 3) A correlation between H-1″ (δ H 5.35) of Gal and C-3 (δ C 133.5) in the heteronuclear multiple bond connectivity (HMBC) spectrum of 1 indicated C-3 as the site of O-glycosylation.…”