- Enzymatic studies of isoflavonoids as selective and potent inhibitors of human leukocyte 5-lipo-oxygenase
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Continuing our search to find more potent and selective 5-LOX inhibitors, we present now the enzymatic evaluation of seventeen isoflavones (IR) and nine isoflavans (HIR), and their in vitro and in cellulo potency against human leukocyte 5-LOX. Of the 26 compounds tested, 10 isoflavones and 9 isoflavans possessed micromolar potency, but only three were selective against 5-LOX (IR-2, HIR-303, and HIR-309), with IC50 values at least 10 times lower than those of 12-LOX, 15-LOX-1, and 15-LOX-2. Of these three, IR-2 (6,7-dihydroxy-4-methoxy-isoflavone, known as texasin) was the most selective 5-LOX inhibitor, with over 80-fold potency difference compared with other isozymes; Steered Molecular Dynamics (SMD) studies supported these findings. The presence of the catechol group on ring A (6,7-dihydroxy versus 7,8-dihydroxy) correlated with their biological activity, but the reduction of ring C, converting the isoflavones to isoflavans, and the substituent positions on ring B did not affect their potency against 5-LOX. Two of the most potent/selective inhibitors (HIR-303 and HIR-309) were reductive inhibitors and were potent against 5-LOX in human whole blood, indicating that isoflavans can be potent and selective inhibitors against human leukocyte 5-LOX in vitro and in cellulo. Of the 26 compounds tested, 10 isoflavones and 9 isoflavans possessed micromolar potency, but only three were selective against 5-LOX (IR-2, HIR-303, and HIR-309), with IC50 values at least 10 times lower than those of 12-LOX, 15-LOX-1, and 15-LOX-2. Docking and steered molecular dynamics were performed to determinate the structure-activity relationship.
- Mascayano, Carolina,Espinosa, Victoria,Sepúlveda-Boza, Silvia,Hoobler, Eric K.,Perry, Steve,Diaz, Giovanni,Holman, Theodore R.
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p. 894 - 901
(2015/06/23)
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- Isoflavans derivatives as inhibitors of soybean lipoxygenase: In-vitro and docking studies
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The lipoxygenases (LOX) are a family of non-heme iron-containing dioxygenases which catalyze the stereospecific insertion of molecular oxygen into arachidonic acid, leading to hydroxy derivatives as end products. In this work, we studied the behavior of s
- Mascayano, Carolina,Rezende, Marcos Caroli,Rivera, Yenifer,Espinosa, Victoria
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p. 935 - 937
(2012/05/05)
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- Synthesis of various kinds of isoflavones, isoflavanes, and biphenyl- ketones and their 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activities
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Forty-eight kinds of isoflavones (8), thirty-one isoflavanes (9), and forty-seven biphenyl-ketones (10, 10') were synthesized from eleven kinds of substituted phenols (11) and six phenylacetic acids (12). Among them, seventy-five compounds are new. The radical scavenging activities of these compounds were evaluated using 1,1- diphenyl-2-picrylhydrazyl (DPPH) at pH 6.0. We found that thirty-nine out of forty-three compounds having a catechol moiety on either the A- or the B-ring exhibited a high activity (ED50=12-54 μM) similar to that of catechin. In these cases, the remaining part of their structure seemed to have little effect on their activity. Many 6- or 8-hydroxyisoflavanes (9E-I) and their biphenyl-ketone derivatives (10E-H) also showed a high activity (ED50=50=26-32 μM). This study suggests that natural isoflavones have the possibilities of exhibiting antioxidant activities through the hydroxylation at the C6-, C8-, or C3'-position or the formation of the isoflavanes (9) and/or the biphenyl-ketone derivatives (10') by metabolism or biotransformation.
- Goto, Hideyuki,Terao, Yoshiyasu,Akai, Shuji
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experimental part
p. 346 - 360
(2009/12/27)
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- SYNTHESIS OF 7-O-β-D-GLUCOPYRANOSIDES OF ISOFLAVONES AND THEIR HETEROCYCLIC ANALOGUES
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The products of the interaction of α-acetobromoglucose with 2,4,5-trihydroxyphenyl benzyl ketone and 2,4-dihydroxyphenyl 4'-hydroxybenzyl ketone and also with their heterocyclic analogues, which are present completely or partially in the enolic form, have been investigated.It has been shown that in this reaction a tetra-O-acetylglucosyl residue is added at the 4-OH hydroxy group of the phenyl residue of the ketone.The compounds obtained have been converted into isoflavone 7-O-glucosides by the action of the Vilsmeier reagent or acetoformic anhydride.
- Pivovarenko, V. G.,Khilya, V. P.
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p. 181 - 186
(2007/10/02)
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- Isoflavones and related compounds, methods of preparing and using and antioxidant compositions containing same
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The present invention concerns isoflavones and related compounds useful as antioxidants and in antioxidant compositions including edible fats and oils. Many of these compounds can be recovered from tempeh, a fermented soybean product. Others can be prepared by chemical modification of those recovered from tempeh. Additionally, all of the compounds can be chemically synthesized. The compounds of the present invention may be used to provide enhanced stability for a wide range of substances subject to oxidative deterioration including edible food products, oils and fats.
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