Agly cones

Hydrolysis is readily accomplished by mixing the extract with an eqnal volume of 4-M HCl and refluxed for 0.5 h. The hydrolyzed mixture is allowed to cool and then subjected to extraction with a small volume of 1-pentanol to obtain the agly-cones, the solvent then being removed by rotary evaporation. The anthocyanidins are then dissolved in a small volume of acidic methanol (0.3% concentrated HCl). 

Kijanolide 117,76 tetronolide 118,76 and chlorothricolide 119,77 the agly-cones of the structurally novel antitumor antibiotics kijimicin, tetrocaricin A, and chlorothrimicin, are highly valued targets for total synthesis. All three structures share a similar octahydronaphthalene fragment 121, which can be obtained by cyclization of 120. Compound 120, appropriately functionalized 2,8,10,12-tetradecatetraene acid, can be constructed via aldol reactions. Two... 

WoUenweber E, Dietz VH, Occurrence and distribution of free flavonoid agly-cones in plants. Phytochemistry 20 869—932, 1981. 

The most important group of compounds for our purposes, the flavonoids, are shown with coumarins in Table VII. The flavonoid agly-cones precipitated nearly quantitatively except for fisetin, myricetin, and tectochrysin. Tectochrysin, 5-hydroxy-7-methoxyflavone, still preceipi-tated to 51% without phloroglucinol even though two of the three... 

Anthocyanins are flavonoid compounds that are widely distributed in plants. They are responsible for blue, purple, violet, magenta, red, and orange plant coloration (Jackman and Smith, 1996). The range of colors associated with anthocyanins results from distinct and varied substitution of the parent C6C3C6 (agly-cone) nucleus (Figure FI.1.2), in addition to acylation patterns and various environmental influences (Jackman and Smith, 1992). 

In reversed-phase HPLC separation of polyphenolics on the basis of polarity, the elution order of polyphenolics may be predicted. The more-polar polyphenolics are generally eluted first under reversed-phase conditions. Glycosylation in flavonoids increases their polarity and therefore their mobility in the re-versed-phase system. The elution order of benzoic acids, hydroxycinnamic acids, and agly-cones of flavonoids can normally be determined on the basis of the number of polar hydroxyl groups and lipophilic methoxyl groups. For additional information about elution order for various classes of polyphenolics, see Background Information. 

Kocienski, P. J. Pontiroli, A. Qun, L. Enan-tiospecific syntheses of pseudopterosin agly-cones. Part 2. Synthesis of pseudopterosin K-L aglycone and pseudopterosin A-F agly-cone via a B-BA-BAC annulation strategy. 

Eight naturally occurring, structurally related avermectins are produced by Streptomyces avermitilis [7], The avermectin polyketide structure is derived from seven acetate and five propionate residues, together with a single 2-methylbutyric acid or isobutyric acid residue which forms the sec-butyl or isopropyl group attached to the C25 of the spiroketal moiety [8,9] (Fig. 1). The avermectin agly-cone is further modified by glycosylation at C13, with the attachment of two O-methylated oleandrose residues and O-methylation at C5. Thus, S. avermitilis... 

Jukic, M., Politeo, O. and Milos, M. (2006) Chemical composition and antioxidant effect of free volatile agli-cones from nutmeg compared to its essential oil. Croatica Chemica Acta 79, 209-214. 

C-glycosylation. In mono-C-deoxyhexosyl derivatives the ions agly-cone + 41 [(M-H)-104] and aglycone + 83 [ X-18] ,... 

Gaffield W (1970) Circular Dichroism, Optical Rotatory Dispersion and Absolute Configuration of Flavanones, 3-Hydroxyflavanones and their Glycosides Determination of Agly-cone Chirality in Flavanone Glycosides. Tetrahedron 26 4093... 

Kang, Q.J., Zhao, P.J., He, H.P. and Shen, Y.M. (2005) Cardenolides and cardiac agly-cone from the stem bark of Trewia nudiflora. Helv. Chim. Acta, 88, 2781-7. 

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