6853-87-8Relevant academic research and scientific papers
Isolation and structure of a new brevetoxin analog, brevetoxin B2, from greenshell mussels from New Zealand
Murata, Kazuya,Satake, Masayuki,Naoki, Hideo,Kaspar, Heinrich F.,Yasumoto, Takeshi
, p. 735 - 742 (1998)
A new brevetoxin analog, brevetoxin B2 (BTXB2), was isolated from greenshell mussels, Perna canaliculus, collected at the time of the neurotoxic shellfish poisoning incident in New Zealand. The structure was elucidated based on NMR, CAD PAB MS/MS, and chemical degradation experiments.
Asymmetric synthesis of (S,R)- and (R,R)-methiin stereoisomers
Kolodiazhna, Anastasy О.,Skliarov, Аleksei I.,Slastennikova, Alena A.,Kolodiazhnyi, Oleg I.
, p. 713 - 717 (2020/05/11)
An asymmetric synthesis of (+)- and (–)-methiine (S-methyl-(R)-cysteine sulfoxide) diastereomers has been developed. These natural sulfur compounds were isolated from a variety of Brassica vegetables. As the starting compound, (R)-cysteine was used, which was methylated to form (R)-S-methylcysteine. Then the oxidation of S-methylcysteine with tert-butyl hydroperoxide catalyzed by the chiral tetra(isopropylate)titanium/(S)- or (R)-Binol complex led to the formation of (1 R,2S)-(+)- or (1 R,2R)-(–)-methiin stereomers.
Engineered Citrobacter freundii methionine γ-lyase effectively produces antimicrobial thiosulfinates
Morozova, Elena A.,Kulikova, Vitalia V.,Rodionov, Alexei N.,Revtovich, Svetlana V.,Anufrieva, Natalya V.,Demidkina, Tatyana V.
, p. 92 - 98 (2016/07/25)
Antimicrobial activity of thiosulfinates in situ produced by mixtures of Citrobacter freundii methionine γ-lyase (MGL) with new substrates, L-methionine and S-(alkyl/allyl)-L-cysteine sulfoxides has been recently demonstrated (Anufrieva et?al., 2015). This opens a way to the rational design of a new biotechnologically relevant antimicrobial drug producer. To increase the efficiency of the enzyme toward sulfoxides, the mutant forms of MGL, with the replacements of active site cysteine 115 with alanine (C115A MGL) and histidine (C115H MGL) were obtained. The replacement of cysteine 115 by histidine results in the loss of activity of the mutant enzyme in the γ-elimination reaction of physiological substrate, whereas the activity in the β-elimination reaction of characteristic substrates persists. However, the catalytic efficiency of C115H MGL in the β-elimination reaction of S-substituted L-cysteine sulfoxides is increased by about an order of magnitude compared to the wild type MGL. The antibacterial activity of C115H MGL mixtures with a number of sulfoxides was assessed against Gram-positive and Gram-negative bacteria. The bacteriostatic effect was more pronounced against Gram-positive than against Gram-negative bacteria, while antibacterial potential proved to be quite similar. Thus, the mutant enzyme C115H MGL is an effective catalyst, in particular, for decomposition of sulfoxides and the pharmacological couples of the mutant form with sulfoxides might be new antimicrobial agents.
A step-by-step crystallization for preparing thio alkyl/alkenyl cysteine sulfoxide method
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Paragraph 0048; 0049, (2017/05/26)
The invention discloses a method for preparing thioalkyl/alkenyl cysteine sulfoxide by fractional crystallization, belonging to the technical field of compound preparation. The method comprises the following steps: adding cysteine or cysteine salts, a sodium hydroxide solution and an R group (alkyl or alkenyl)-derived material into absolute ethanol in sequence for reaction to synthesize coarse ACSs, re-crystallizing ACSs, purifying, oxidizing to form ACSOs, and fractionally crystallizing to obtain natural dextrorotatory ACSOs, wherein the R group-derived material is replaced to synthesize different types of ACSOs in allium; enantiomers in racemes are separated by adopting the fractional crystallization method to obtain natural dextrorotatory ACSOs with optical activity. Compared with a conventional extraction method, the method has the characteristics that the yield and the purity are high, a conventional complicated extraction process is avoided, the product has the optical activity, and the physical property is close to that of natural extract; the product is used in the fields of health products, pharmaceuticals and the like, the effects of resisting bacteria and cancers, reducing blood fat and the like of ACSOs are brought into play, or the product serves as an intermediate such as an active ingredient-diallyl thiosulfinate for synthesizing allium.
IMPROVEMENTS IN OR RELATING TO ALLIUM EXTRACTS
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Page/Page column 84, (2015/02/02)
The present invention relates to improvements in or relating to Allium extracts. In particular, it relates to improvements in or relating to extending the therapeutic half- life or duration of Allium extracts. The invention also relates to the synthesis of certain thiosulfinate compounds, especially to the synthesis of methyl allyl thiosulfinate and allyl methyl thiosulfinate, in particular from either methiin or alliin alone or a mixture of both. The invention further relates to the synthesis of methyl allyl thiosulfinate, allyl methyl thiosulfinate, allicin, and methyl methyl thiosulfinate in a mixture with varying molar or mass ratios depending on the reaction conditions, in particular from either methiin or alliin alone or a mixture of both. A high yielding, optimized synthesis of allicin starts from alliin, whereas methyl methyl thiosulfinate is advantageously obtained from methiin. Also provided is a kit comprising methiin in a first container and/or alliin in a second container and an allinase source, in particular garlic powder in a third container. Finally, the invention provides a method of preparing a mixture of methyl allyl thiosulfinate, allyl methyl thiosulfinate, allyl allyl thiosulfinate (allicin) and methyl methyl thiosulfinate from methiin and pieces of an Allium species.
IMPROVEMENTS IN OR RELATING TO ALLIUM EXTRACTS
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Page/Page column 75, (2014/02/15)
The present invention relates to improvements in or relating to Allium extracts. In particular, it relates to improvements in or relating to extending the therapeutic half- life or duration of Allium extracts. The invention also relates to the synthesis of certain thiosulfinate compounds, especially to the synthesis of methyl allyl thiosulfinate and allyl methyl thiosulfinate, in particular from either methiin or alliin alone or a mixture of both. The invention further relates to the synthesis of methyl allyl thiosulfinate, allyl methyl thiosulfinate, allicin, and methyl methyl thiosulfinate in a mixture with varying molar or mass ratios depending on the reaction conditions, in particular from either methiin or alliin alone or a mixture of both. A high yielding, optimized synthesis of allicin starts from alliin, whereas methyl methyl thiosulfinate is advantageously obtained from methiin. Also provided is a kit comprising methiin in a first container and/or alliin in a second container and an allinase source, in particular garlic powder in a third container. Finally, the invention provides a method of preparing a mixture of methyl allyl thiosulfinate, allyl methyl thiosulfinate, allyl allyl thiosulfinate (allicin) and methyl methyl thiosulfinate from methiin and pieces of an Allium species.
Oxidation by chlorine dioxide of methionine and cysteine derivatives to sulfoxides
Loginova,Rubtsova,Kuchin
experimental part, p. 752 - 754 (2009/05/09)
Methionine and cysteine derivatives were oxidized asymmetrically by chlorine dioxide to sulfinyl derivatives.
Determination of S-methyl-, S-propyl-, and S-propenyl-L-cysteine sulfoxides by gas chromatography-mass spectrometry after tert-butyldimethylsilylation.
Tsuge, Kouichiro,Kataoka, Mieko,Seto, Yasuo
, p. 4445 - 4451 (2007/10/03)
A gas chromatographic-mass spectrometric method for the determination of S-methyl-L-cysteine sulfoxide (1), S-propyl-L-cysteine sulfoxide (2), and S-propenyl-L-cysteine sulfoxide (3), specific marker compounds in the genus Allium, is described. The target amino acids were converted to the tert-butyldimethylsilyl derivatives. The products were silylated on the amino and carboxyl groups and on an additional oxygen atom and were separated on a nonpolar capillary column. That incorporation of three tert-butyldimethylsilyl groups had occurred was verified by mass spectrometry, which gave an m/z 302 fragment as base peak (amino acid side chain eliminated ion) and m/z 436 (1), 464 (2), or 462 (3) as major peaks (tert-butyl function eliminated ion), by electron impact ionization. The detection limits for 1 and 2 under selected ion monitoring at m/z 436 (1) and m/z 464 (2), respectively, were determined to be 0.3 and 1.8 ng per injection. To clean up the analytes from the solvent extract of onion, as a representative food material, onion, the sample solution was subjected to combined solid phase extraction. The eluate from a Sep-Pak C(18) cartridge was applied to a Bond Elut SCX cartridge (H(+) form), followed by washing with 0.1 M hydrochloric acid and elution with 0.5 M ammonia. From a simulated matrix solution containing 5% sucrose, 1 and 2 were extracted quantitatively, and the detection yield was approximately 75%. The contents of 1, 2, and 3 in commercial onion were estimated to be 0.3, 3.1, and 3.0 mg, respectively, per gram of fresh weight.
Differential inhibition of human platelet aggregation by selected Allium thiosulfinates
Briggs, William H.,Xiao, Hang,Parkin, Kirk L.,Shen, Cunxi,Goldman, Irwin L.
, p. 5731 - 5735 (2007/10/03)
Thiosulfinates (TSs) have been implicated as a principle source of the antiplatelet property of raw onion and garlic juice. The in vitro responses of human platelets to dosages of four TSs were measured using whole blood aggregometry and compared by regression analysis. Of the compounds evaluated, methyl methane-TS (MMTS), propyl propane-TS (PPTS), and 2-propenyl 2-propene-TS (allicin) are present in freshly cut Allium vegetables, whereas ethyl ethane-TS (EETS) has not been detected. All TSs were synthesized using a model reaction system. PPTS and allicin had the strongest antiplatelet activity at 0.4 mM, inhibiting aggregation by 90 and 89%, respectively. At the same concentration, EETS and MMTS were significantly weaker, inhibiting 74 and 26%, respectively. Combinations of TSs were not additive in their inhibition of aggregation, indicating that the antiplatelet potential of Allium extracts cannot be easily predicted by quantifying organosulfur components. EETS, PPTS, and allicin were significantly more potent platelet inhibitors than aspirin at nearly equivalent concentrations.
In vitro biogeneration of pure thiosulfinates and propanethial-S-oxide
Shen, Cunxi,Parkin, Kirk L.
, p. 6254 - 6260 (2007/10/03)
A model reaction system was developed for generating, pure thiosulfinates and propanethial-S-oxide (PTSO) using an isolated alliinase (EC 4.4.1.4) and isolated or synthetic alk(en)yl-L-cysteine sulfoxides (ACSO). Reaction yields ranged from 30 to 60% after 3 h at 21-23°C, and organosulfur reaction products were extracted into CHCl3 to yield product preparations of controlled composition. A pure thiosulfinate or PTSO was derived from a single ACSO, and a preparation containing a mixture of four thiosulfinate species was derived from reaction mixtures employing binary ACSO substrate systems. Identities of homologous thiosulfinates and PTSO were confirmed by 1H NMR. This approach has the potential to be used as a preparative tool for yielding pure thiosulfinates and PTSO to facilitate the study of chemical and biological properties of this group of compounds or as a means to study the dynamics of organosulfur chemistry in preparations from Allium spp.
