- HPLC separation of sulforaphane enantiomers in Broccoli & its sprouts by transformation into diastereoisomers using derivatization with (S)-Leucine
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Racemic sulforaphane, which was derivatized with (S)-leucine (L-leucine), was resolved by reversed phase HPLC with UV detection. The optimum mobile phase conditions were found to be 10 mM citric acid (pH 2.8) containing 22% methanol at 35 °C using detection at 254 nm. Sulforaphane enantiomers in florets and stems of five brands of broccoli and leaves and stems of three brands of broccoli sprouts were analyzed by the proposed HPLC method. Both sulforaphane enantiomers were detected in all of the samples. The S/R ratios of sulforaphane in broccoli samples were 1.5-2.6/97.4-98.5% for florets and 5.0-12.1/87.9-95.0% for stems. The S/R ratios in broccoli sprout samples were higher than those in broccoli samples and were found to be 8.3-19.7/80.3-91.7% for leaves and 37.0-41.8/58.2-63.0% for stems. (S)-Sulforaphane detected in the broccoli and its sprout samples was positively identified by separately using an HPLC with a chiral column (Chiralpak AD-RH) and mass spectrometry.
- Okada, Makiko,Yamamoto, Atsushi,Aizawa, Sen-Ichi,Taga, Atsushi,Terashima, Hiroyuki,Kodama, Shuji
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- Novel gram-scale production of enantiopure R-Sulforaphane from tuscan black kale seeds
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Dietary R-sulforaphane is a highly potent inducer of the Keap1/Nrf2/ARE pathway. Furthermore, sulforaphane is currently being used in clinical trials to assess its effects against different tumour processes. This study reports an efficient preparation of enantiopure R-sulforaphane based on the enzymatic hydrolysis of its natural precursor glucoraphanin. As an alternative to broccoli seeds, we have exploited Tuscan black kale seeds as a suitable source for gram-scale production of glucoraphanin. The defatted seed meal contained 5.1% (w/w) of glucoraphanin that was first isolated through an anion exchange chromatographic process, and then purified by gel filtration. The availability of glucoraphanin (purity . 95%, weight basis) has allowed us to develop a novel simple hydrolytic process involving myrosinase (EC 3.2.1.147) in a biphasic system to directly produce R-sulforaphane. In a typical experiment, 1.09 g of enantiopure R-sulforaphane was obtained from 150 g of defatted Tuscan black kale seed meal.
- De Nicola, Gina Rosalinda,Rollin, Patrick,Mazzon, Emanuela,Iori, Renato
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- Synthesis of (R)-sulforaphane using [CpRu((R,R)-CHIRAPHOS)]+ as chiral auxiliary
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A new enantioselective (80% ee) synthesis of (R)-sulforaphane and its epimer (S)-sulforaphane is described, which makes use of the pseudotetrahedral complex fragment [CpRu(CHIRAPHOS)]+ as a chiral auxiliary. Reaction of the chloride complexes [CpRu(L-L)Cl] [L-L =1,2-bis(diphenylphosphino)ethane (dppe), (2S,3S) and (2R,3R)-bis(diphenylphosphino) butane ((S,S)- and (R,R)-CHIRAPHOS, respectively)] with phthalimidobutyl methyl sulfide gives the thioether complexes [CpRu(L-L)(MeSC4H8NPhth)]PF6. Oxygen transfer from dimethyldioxirane (DMD) produces the corresponding sulfoxide complexes in high yield and high diastereoselectivity. Cleavage of the phthaloyl group with aqueous hydrazine and subsequent reaction with thiophosgene yields the sulforaphane complexes [CpRu(L-L)(MeS(O)C4H8NCS)]PF6. Treatment of these with sodium iodide finally liberates the sulforaphane without noticeable racemization.
- Schenk, Wolfdieter A.,Duerr, Michael
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- PREPARATION OF (R)-SULFORAPHANE BY BIOTRANSFORMATION USING HELMINTHOSPORIUM SPECIES NRRL 4671
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The fungus Helminthosporium species NRRL 4671 oxidizes 1-isothiocyanato-4-(methylthio)butane to (-)-1-isothiocyanato-(4R)-(methylsulfinyl)butane (sulforaphane).Helminthosporium also converts 1-methylthio-4-(N-phthalimidyl)butane to the (R) sulfoxide.
- Holland, Herbert L.,Brown, Frances M.,Larsen, Brett G.
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- BIOTRANSFORMATION OF ORGANIC SULFIDES. PART 7. FORMATION OF CHIRAL ISOTHIOCYANATO SULFOXIDES AND RELATED COMPOUNDS BY MICROBIAL BIOTRANSFORMATION
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The fungi Helminthosporium species NRRL 4671 and Mortierella isabellina ATCC 42613 have been used for the biotransformation of a series of isothiocyanatoalkyl methyl sulfides and their synthetic precursors, ω-(methylthio)alkylphthalimides.H. species gave predominantly (S) sulfoxides in all cases; M. isabellina gave (R) isothiocyanatoalkyl methyl sulfoxides, but in the case of two ω-(methylthio)alkylphthalimides substantial conversion of sulfoxide to sulfone resulted in the isolation of the former with predominant (S) configuration.A correction is made of the previously reported configurations of two biotransformation products (Tetrahedron: Asymmetry, 1994, 5, 1129).
- Holland, Herbert L.,Brown, Frances M.,Larsen, Brett G.,Zabic, Mirjana
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- (RS)-glucoraphanin purified from Tuscan black kale and bioactivated with myrosinase enzyme protects against cerebral ischemia/reperfusion injury in rats
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Ischemic stroke is the result of a transient or permanent reduction in cerebral blood flow caused by the occlusion of a cerebral artery via an embolus or local thrombosis. Restoration of blood supply to ischemic tissues can cause additional damage known as reperfusion injury that can be more damaging than the initial ischemia. This study was aimed to examine the possible neuroprotective role of (RS)-glucoraphanin, bioactivated with myrosinase enzyme (bioactive RS-GRA), in an experimental rat model of brain ischemia/reperfusion injury (I/R). RS-GRA is a thiosaccharidic compound found in Brassicaceae, notably in Tuscan black kale (Brassica oleracea L. var. acephala sabellica). The mechanism underlying the inhibitory effects of bioactive RS-GRA on inflammatory and apoptotic responses, induced by carotid artery occlusion in rats, was carefully examined. Cerebral I/R was induced by the clamping of carotid artery for 1 h, followed by 40 min of reperfusion through the release of clamp. Our results have clearly shown that administration of bioactive RS-GRA (10 mg/kg, i.p.) 15 min after ischemia, significantly reduces proinflammatory parameters, such as inducible nitric oxide synthase expression (iNOS), intercellular adhesion molecule 1 (ICAM-1), nuclear factor (NF)-kB traslocation as well as the triggering of the apoptotic pathway (TUNEL and Caspase 3 expression). Taken together our data have shown that bioactive RS-GRA possesses beneficial neuroprotective effects in counteracting the brain damage associated to I/R. Therefore, bioactive RS-GRA, could be a useful treatment in the cerebral ischemic stroke.
- Giacoppo, Sabrina,Galuppo, Maria,Iori, Renato,De Nicola, Gina Rosalinda,Bramanti, Placido,Mazzon, Emanuela
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- Enantiopure sulforaphane analogues with various substituents at the sulfinyl sulfur: Asymmetric synthesis and biological activities
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(Chemical Equation Presented) A convergent and high-yielding approach for the asymmetric synthesis of sulforaphane 2 and four analogues differently substituted at the sulfinyl sulfur has been developed. The key step of the synthesis is the diastereoselect
- Khiar, Noureddine,Werner, Sabine,Mallouk, Siham,Lieder, Franziska,Alcudia, Ana,Fernandez, Inmaculada
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experimental part
p. 6002 - 6009
(2009/12/26)
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- Asymmetric Synthesis of Chiral Sulfinate Esters and Sulfoxides. Synthesis of Sulforaphane
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Reaction of the chiral auxiliary trans-2-phenylcyclohexanol (1) with thionyl chloride afforded a nearly equal mixture of two diastereomeric chlorosulfite esters (6).Treatment of this mixture with an equivalent amount of a dialkylzinc reagent (Me, Et, i-Pr) afforded high levels of conversion of both chlorosulfite esters to (mainly) a single diastereomer of the sulfinate ester (7).Levels of absolute stereochemical induction ranged from 10:1 to 96:4 under conditions affording high chemical yields.The method was employed for the separate synthesis of both enantiomers of sulforaphane (13).
- Whitesell, James K.,Wong, Man-Shing
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p. 597 - 601
(2007/10/02)
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