A New Flavonol Glycoside Derivative from Leaves of Moldenhawera nutans

Abstract

The ethyl acetate extract of leaves of Moldenhawera nutans Queiroz & Alkin (Leguminosae) furnished, besides methyl gallate and gallic acid, the flavonols named laricetrin, laricetrin 3-glucoside and laricetrin 3-galactoside as well as the new one named laricetrin 5-galloyl-3--d-xylopyranoside. It also was isolated from the hexane extract: -sitosterol, lupenone, -amyrinone, α-amyrinone, lupeol, -amyrin, α-amyrin and α-tocopherol. The antioxidant activities of flavonoids were measured through DPPH radical scavenging and inhibition of auto-oxidation of -carotene methods. The structures of the compounds were determined by analyses of spectral data. This is the first report dealing with phytochemical studies of leaves of M. nutans. In addition this current work describes the unequivocal attribution of 1 H NMR and 13 C NMR data of laricetrin.

Flavonoids and their glycosides, including anthocyanins

“…An interesting case is that of a compound obtained from leaves of Moldenhawera nutans (Leguminosae) which was identified as 5-galloyllarycitrin 3-O-b-xylopyranoside. 269 However, in the 1 H NMR spectrum the chemical shift value for H-6 of the aglycone A-ring is essentially identical to that found in larycitrin itself, whereas H-2 of the sugar moiety shows a substantial downfield shift. This is a clear indication that the galloyl group should be placed at 2-OH of the sugar and not 5-OH of the aglycone.…”

“…A number of flavonol O-glycosides published as new in the 2004-2006 period have been omitted from Table 2 either because their characterisation appears incomplete, or difficulties exist in reconciling the structures proposed for them with the accompanying spectroscopic data. [251][252][253][254][255][256][257][258][259][260][261][262][263][264][265][266][267][268][269] In terms of incomplete characterisation, a common problem is that interglycosidic linkages and points of attachment between aglycone and glycosyl moieties are not always fully defined. This is particularly important where unusual linkages are suggested.…”

Methylated derivatives of myricetin enhance life span in Caenorhabditis elegans dependent on the transcription factor DAF-16

“…10 laricitrin is found in Moldenhawera nutans 11 and myricetrintrimethylether is a constituent of Bridelia ferruginea stem bark. 10 laricitrin is found in Moldenhawera nutans 11 and myricetrintrimethylether is a constituent of Bridelia ferruginea stem bark.…”

“…These three compounds were chosen since (i) it was hypothesized that the 2′,3′,4′-OH groups in ring B are primarily relevant for the life span extension induced by myricetin and (ii) due to the relevance of these compounds as ingredients of pharmacologically active herbs which are used in traditionally medicine: syringetin is a component of the leaves of Zanthoxylum bungeanum Maxim. 10 laricitrin is found in Moldenhawera nutans 11 and myricetrintrimethylether is a constituent of Bridelia ferruginea stem bark. 12 In addition to life span analyses, we also investigated the effect of the methylated derivatives on surrogate markers in the nematode, e.g.…”

Therapeutic action and underlying mechanisms of a combination of two pentacyclic triterpenes, α‐ and β‐amyrin, in a mouse model of colitis

“…In the last 10 years, studies have shown a systemic anti-inflammatory action of the essential oil from leaves and resins of some Protium species (Siani et al, 1999;Rudiger et al, 2007). The main bio-active components in those resins, a-amyrin and b-amyrin (Figure 1), are pentacyclic triterpenes isolated from P. kleinii as well other plant species (Oliveira et al, 2005;Otuki et al, 2005b;do Vale et al, 2005). Some experimental evidence has pointed that a-amyrin exhibits systemic anti-nociceptive, antiinflammatory, antipruritic, hepatoprotective and gastroprotective properties, when assessed in vivo (Kweifio-Okai et al, 1994;Recio et al, 1995;Oliveira et al, 2004a,b).…”