Anthochlor Pigments of Cosmos sulphureus, Coreopsis lanceolata and C. saxicola

04/2002; DOI: 10.1021/ja01104a036
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    Journal of The Japanese Society for Horticultural Science - J JPN SOC HORT SCI. 01/2009; 78(3):263-272.
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    ABSTRACT: Infusions of Coreopsis tinctoria flowering tops have traditionally been used in Portugal to control hyperglycaemia but no pharmacological or toxicological studies have been reported until now. The chalcones marein and okanin were isolated from the aqueous extract, together with the 2S-3',4',7,8-tetrahydroxyflavanone. The content of marein in extracts was determined by HPLC-UV and the radical scavenging capacity evaluated by the DPPH method (EC(50) = 21 microg/mL). Glucose intolerance was induced by a single intraperitoneal injection of streptozotocin in saline (40 mg/Kg). After three weeks of oral treatment with C. tinctoria extract (500 mg/Kg/day) the animals were no longer glucose-intolerant (p > 0.05). Additionally, this oral treatment caused no hepatotoxicity in the rats, as determined by blood alanine and aspartate transaminases. A single administration of extract had no effect on oral glucose tolerance in normal Wistar rats. The extract also had no effect on insulin secretion by MIN6 cells. In conclusion, C. tinctoria infusion is able to abolish the streptozotocin-induced glucose-intolerance in rats after three weeks of oral treatment by a mechanism other than induction of insulin secretion. The recovery of beta-pancreatic function mediated by an antioxidant mechanism is a possibility that deserves further investigation.
    Phytotherapy Research 10/2009; 24(5):699-705. · 2.07 Impact Factor
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    ABSTRACT: The phenolic constituents of plants are concerned in the quality of plant products, especially in respect of appearance and texture. Many such constituents are concerned in appearance by virtue of their properties as pigments, and many can act as substrates for enzymic browning. Certain phenolic substances are astringent. Lignin is another phenolic constituent which, even in small quantities, markedly increases the toughness of plant cell wall. The chemical nature of the phenolic constituents, and current views as to the pathway of their synthesis in plants, are discussed.Die phenolischen Stoffe der Pflanzen spielen eine Rolle bei der Bestimmung der Pflanzenqualitt, nmlich was Aussehen und Textur anbelangt. Viele von diesen Stoffen geben dem Produkt seine Farbe; andere stellen Substrate fr eine enzymbedingte Brunung. Manche dieser Substanzen wirken astringierend. Lignin ist ein anderer phenolischer Bestandteil, der, selbst in kleinen Mengen, die Rigiditt der pflanzlichen Zellwnde wesentlich verstrkt.Die chemische Struktur dieser Substanzen wird beschrieben, so wie die Wege ihrer Bildung in den Pflanzen.Les constituants phnoliques des vgtaux interviennent dans la qualit des produits vgtaux, principalement en ce qui concerne l'aspect et la texture. Beaucoup de ces constituants donnent au produit sa couleur: certains sont les substrats du brunissement enzymatique. Certaines substances phnoliques sont astringentes. La lignine est un autre constituant phnolique qui, mne en trs petite quantit, augmente considrablement la rigidit des parois cellulaires.Le prsent expos dcrit la nature chimique de ces substances et les notions courantes sur les voies de leur synthse dans les vgtaux.
    Plant Foods for Human Nutrition 01/1958; 3-4(1):440-455. · 2.36 Impact Factor