New arbutin derivatives from leaves of Grevillea robusta and Hakea saligna

Phenolic Glycosides with Antimalarial Activity from Grevillea “Poorinda Queen”

“…For comparison purposes, chloroquine, the positive control, suppressed P. berghei infection by 58% and 97% at 1 and 2 mg/kg given daily for 4 days, respectively, which was in accord with previous findings. 9 The are several literature reports of phenolic glycosides belonging to the arbutin (6) structure class [10][11][12][13][14] having been isolated from several different genera of plants, including Vaccinium dunalianum, 10 GreVillea robusta, 6,11 Hakea saligna, 11 Viburnum dilatatum, 12 Veronica turrilliana, 13 and Bacopa procumbens. 13 Only one of these reports, however, documents biological activity, with both 6 and the 6′-caffeoyl derivative of 6 having weak radical scavenging activity.…”

“…The are several literature reports of phenolic glycosides belonging to the arbutin ( 6 ) structure class − having been isolated from several different genera of plants, including Vaccinium dunalianum , Grevillea robusta , , Hakea saligna , Viburnum dilatatum , Veronica turrilliana , and Bacopa procumbens . Only one of these reports, however, documents biological activity, with both 6 and the 6′-caffeoyl derivative of 6 having weak radical scavenging activity .…”

Chemical constituents of Bacopa Procumbens

“…Repeated column chromatography (CC) and HPLC of n-butanol fraction afforded nine compounds (1)(2)(3)(4)(5)(6)(7)(8)(9), the water fraction gave three compounds (10)(11)(12) and the chloroform fraction yielded two compounds (13,14). The structures of the known compounds (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) were identified by comparison of their physicochemical data with those reported in the literature. The structures of unknown compounds 1 and 2 were elucidated as follows.…”

“…Further, comparison of the spectral data of 2 with those of known compound 4-hydroxyphenyl-6 0 -(3,4 00 -dihydroxycinnamoyl)-O--D-glucopyranoside (3) [6,7], the structure of CHEMICAL CONSTITUENTS OF B. PROCUMBENS 133 compound 2 was established as 4-hydroxyphenyl-6 0 -(3 00 -methoxy, 4 00 -hydroxycinnamoyl)-O--D-glucopyranoside, named procumboside B, isolated for the first time from the plant source. In addition to compounds 1 and 2, 12 known compounds, 4-hydroxyphenyl-6 0 -(3 00 ,4 00 -dihydroxycinnamoyl)-O--D-glucopyranoside (3) [6,7], 4-hydroxyphenyl-6 0 -(4 00 -hydroxycinnamoyl)-O--D-glucopyranoside (4) [6,8], arbutin (5) [6], linarin (6) [9], 3 0 -hydroxy-4 0 -methoxyisocutellarein-7-O--D-glucopyranoside 7 [10], diosmnin (8) [10], -sitosterol--D-glucoside (9) [11], mixture of and -D-glucose (10) [5], sucrose (11) [5], manitol (12) [12], -sitosterol (13) [13] and lupeol (14) [14] have also been isolated. These were identified by direct comparison of their physicochemical data with those reported in the literature.…”

Minor Phenolic Constituents of Grevillea robusta and Hakea saligna

“…Parallel studies on Proteaceae members naturalised in India revealed the presence of other new phenolic com ponents from wood [4,5] and leaves [6] of G. robusta and Hakea saligna. We wish to report now the oc currence of few minor constituents from wood and leaves of these species, extraction procedures being described earlier [4][5][6], G. robusta, wood: The combined acetone and methanol extract after fractionation on silica gel column followed by purification on preparative S i0 2-TLC in solvent Et0Ac-H20-M e0H (40:5.4:6.6) afforded compounds (A) and (B 6 H, ArO-COCH3), 2.08 (s, 3H, -C H 20 -C 0 C H 3) and 2.04 (s, 3H, -CH20 -COCH3). These data suggested it to be a disyringyl lignan, the physical properties being closely resembling to lyoniresinol [7], How ever, its co-IR and co-TLC with authentic sample showed some minor differences.…”