- Effect of physicochemical parameters on the stability and activity of garlic alliinase and its use for in-situ allicin synthesis
-
Garlic is a well-known example of natural self-defence system consisting of an inactive substrate (alliin) and enzyme (alliinase) which, when combined, produce highly antimicrobial allicin. Increase of alliinase stability and its activity are of paramount importance in various applications relying on its use for in-situ synthesis of allicin or its analogues, e.g., pulmonary drug delivery, treatment of superficial injuries, or urease inhibitors in fertilizers. Here, we discuss the effect of temperature, pH, buffers, salts, and additives, i.e. antioxidants, chelating agents, reducing agents and cosolvents, on the stability and the activity of alliinase extracted from garlic. The effects of the storage temperature and relative humidity on the stability of lyophilized alliinase was demonstrated. A combination of the short half-life, high reactivity and non-specificity to particular proteins are reasons most bacteria cannot deal with allicin's mode of action and develop effective defence mechanism, which could be the key to sustainable drug design addressing serious problems with escalating emergence of multidrug-resistant (MDR) bacterial strains.
- Janska, Petra,Knejzlík, Zdenek,Perumal, Ayyappasamy Sudalaiyadum,Jurok, Radek,Tokarova, Viola,Nicolau, Dan V.,Tepanek, FrantisekS,Kaspar, Ondrej
-
-
- Expanding the Structural Diversity of Protein Building Blocks with Noncanonical Amino Acids Biosynthesized from Aromatic Thiols
-
Incorporation of structurally novel noncanonical amino acids (ncAAs) into proteins is valuable for both scientific and biomedical applications. To expand the structural diversity of available ncAAs and to reduce the burden of chemically synthesizing them, we have developed a general and simple biosynthetic method for genetically encoding novel ncAAs into recombinant proteins by feeding cells with economical commercially available or synthetically accessible aromatic thiols. We demonstrate that nearly 50 ncAAs with a diverse array of structures can be biosynthesized from these simple small-molecule precursors by hijacking the cysteine biosynthetic enzymes, and the resulting ncAAs can subsequently be incorporated into proteins via an expanded genetic code. Moreover, we demonstrate that bioorthogonal reactive groups such as aromatic azides and aromatic ketones can be incorporated into green fluorescent protein or a therapeutic antibody with high yields, allowing for subsequent chemical conjugation.
- Wang, Yong,Chen, Xiaoxu,Cai, Wenkang,Tan, Linzhi,Yu, Yutong,Han, Boyang,Li, Yuxuan,Xie, Yuanzhe,Su, Yeyu,Luo, Xiaozhou,Liu, Tao
-
supporting information
p. 10040 - 10048
(2021/03/26)
-
- Composition for promoting differentiation of skin keratinocyte comprising a SAC derivatives or a SMC derivatives
-
The present invention relates to a composition for promoting keratinocyte differentiation. More specifically, SAC derivative or SMC derivatives as an active ingredient promotes differentiation of keratinocytes to promote skin keratinocyte differentiation, has excellent anti-wrinkling effect, skin barrier recovery effect, and is applicable to pharmaceutical, cosmetic, soap, body, shampoo and pack.
- -
-
Paragraph 0028-0031; 0033-0035; 0086-0089; 0091-0093; 0136
(2021/02/02)
-
- Type of complex-BSA binding forces affected by different coordination modes of alliin in novel water-soluble ruthenium complexes
-
Three novel water-soluble ruthenium complexes having differently bound alliin ligands were prepared by solution synthesis and characterized by chemical analysis, and infrared, mass, nuclear magnetic resonance and electron paramagnetic resonance spectrosco
- Zahirovi?, Adnan,?ili?, Dijana,Paveli?, Sandra Kraljevi?,Huki?, Mirsada,Muratovi?, Senada,Harej, Anja,Kahrovi?, Emira
-
p. 5791 - 5804
(2019/04/17)
-
- Structure-activity relationship study and biological evaluation of SAC-Garlic acid conjugates as novel anti-inflammatory agents
-
A series of S-allyl-L-cysteine (SAC) with garlic acid conjugates as anti-inflammatory agents were designed and synthesized. Among the 40 tested compounds, SMU-8c exhibited the most potent inhibitory activity to Pam3CSK4-induced nitric oxide (NO) in RAW264.7 macrophages with IC50 of 22.54 ± 2.60 μM. The structure-activity relationship (SAR) study suggested that the esterified carboxyl group, carbon chain extension and methoxylation phenol hydroxy could improve the anti-inflammatory efficacy. Preliminary anti-inflammatory mechanism studies showed that SMU-8c significantly down-regulated the levels of Pam3CSK4 triggered TNF-α cytokine in human THP-1 cells, mouse RAW 264.7 macrophages, as well as in ex-vivo human peripheral blood mononuclear cells (PBMC) with no influence on cell viability. SMU-8c specifically blocked the Pam3CSK4 ignited secreted embryonic alkaline phosphatase (SEAP) signaling with no influence to Poly I:C or LPS triggered TLR3 or TLR4 signaling. Moreover, SMU-8c suppressed TLR2 in HEK-Blue hTLR2 cells and inhibited the formation of TLR1-TLR2, and TLR2-TLR6 complex in human PBMC. In summary, SMU-8c inhibited the TLR2 signaling pathway to down-regulate the inflammation cytokines, such as NO, SEAP and TNF-α, to realize its anti-inflammatory activity.
- Bi, Jingjie,Wang, Wenqing,Du, Junxi,Chen, Kun,Cheng, Kui
-
p. 233 - 245
(2019/07/02)
-
- S-allyl-L-cysteine sulfoxide, a garlic odor precursor, suppresses elevation in blood ethanol concentration by accelerating ethanol metabolism and preventing ethanol absorption from gut
-
Alcoholic beverages are enjoyed together with meals worldwide, but their excessive intake is associated with an increased risk of various diseases. We investigated whether S-allyl-L-cysteine sulfoxide (ACSO), a sulfuric odor precursor of garlic, suppresses elevation in plasma ethanol concentration by accelerating ethanol metabolism and preventing ethanol absorption from the gut in rats. ACSO and garlic extract with a high ACSO content (Garlic-H) suppressed elevation in concentrations of ethanol and acetaldehyde in plasma and promoted the activities of alcohol dehydrogenase and aldehyde dehydrogenase. However, ACSO and Garlic-H did not affect plasma acetate so much. Furthermore, we examined the change in plasma ethanol concentration by injecting ACSO or Garlic-H into the ligated stomach or jejunum together with ethanol solution. ACSO and Garlic-H suppressed the absorption of ethanol from the stomach and jejunum, but suppression in the jejunum was less than in the stomach. In conclusion, ACSO inhibits ethanol absorption and accelerates ethanol metabolism.
- Uto-Kondo, Harumi,Hase, Ayumu,Yamaguchi, Yusuke,Sakurai, Ayaka,Akao, Makoto,Saito, Takeshi,Kumagai, Hitomi
-
p. 724 - 731
(2018/04/12)
-
- Derivative of Kutkin dimer analog JJA-D0 or its pharmaceutically acceptable salt, preparation method and use thereof
-
The invention relates to a derivative of Kutkin dimer analog JJA-D0 or its pharmaceutically acceptable salt, a preparation method and use thereof. The compound has a structure shown as a general formula (I). According to the invention, an alkyl group, an aryl group, a heteroaryl group, an alkoxycarbonylalkyl group, an acyl group, a sulfonate group, an antioxidant group such as a lipoic acid group,a H2S donor group such as a cysteine group, and a NO donor group such as a nitrate group are introduced to JJA-D0, and a series of structurally novel compounds can be synthesized and disclosed. The compounds inhibit NADPH oxidase and have superior anti-oxidation and anti-inflammatory pharmacological mechanisms by comparing with Kutkin, the compounds also have donor groups that provide NO and H2S,can further enhance pharmacological activity, and can be a new class of multifunctional compounds. The disclosed JJA-D0 derivative can be used for preparing health products or drugs for prevention ortreatment of diseases associated with NADPH oxidase, diseases associated with free radicals, diseases associated with inflammation, diseases associated with NO, and diseases associated with H2S.
- -
-
Paragraph 0112; 0115; 0116
(2019/01/08)
-
- Unnatural amino acid synthesis by thermostable O-phospho-L-serine sulfhydrylase from hyperthermophilic archaeon Aeropyrum pernix K1
-
O-Acetyl-L-serine sulfhydrylase (OASS) from plants and bacteria synthesizes cysteine and unnatural amino acids that are important building blocks for active pharmaceuticals and agrochemicals. A thermostable O-phospho-L-serine sulfhydrylase from hyperthermophilic archaeon Aeropyrum pernix K1 (OPSSAp) exhibits a function similar to OASS. In the present study, we examined the synthesis of various unnatural amino acids using OPSSAp and demonstrated OPSSAp could efficiently synthesize various sulfur-containing amino acids. OPSSAp would be useful for industrial production of biologically important unnatural amino acids.
- Nakamura, Takashi,Kunimoto, Kohei,Yuki, Toru,Ishikawa, Kazuhiko
-
supporting information
p. 1789 - 1792
(2017/11/23)
-
- NEW COMPOUNDS WITH ANTIOXIDANT AND ANTIAGING ACTIVITY
-
The present invention describes new derivatives of S-allyicysteine with antioxidant and antiaging activity. Said derivatives can be used alone or in a combined formulation with other compounds with known activity.
- -
-
Page/Page column 27
(2017/06/30)
-
- Tacrine-allyl/propargylcysteine-benzothiazole trihybrids as potential anti-Alzheimer's drug candidates
-
On continuing our research into new drug candidates for Alzheimer's disease (AD), we have designed, synthesized and evaluated a series of multifunctional trihybrid agents. The design strategy was based on the incorporation of a benzothiazole (BTA) moiety on a series of very recently reported bihybrids, resulting from the conjugation of a tacrine (TAC) with natural based moieties, namely S-allylcysteine (SAC) (garlic constituent) and S-propargylcysteine (SPRC). Thus, in addition to the acetylcholinesterase inhibition (AChEI) and anti-ROS capacity of the bihybrids (TAC-SAC/SPRC), the new trihybrids (TAC-SAC/SPRC-BTA) appeared endowed with a 5-fold capacity for inhibition of amyloid beta-peptide (Aβ) aggregation. The BTA moiety led also to considerable enhancement of the AChEI on the trihybrids, which molecular modeling suggested as being due to simultaneous binding to the catalytic active site and peripheral anionic site of AChE. The trihybrids were also assessed for MAO inhibition, but resulted in lower activity than expected, ascribed to the low accessibility of the propargyl groups to the enzyme active site. Finally, the effects of the compounds on the viability of neuroblastome cells stressed with Aβ42 and H2O2 showed moderate cell protection. Overall, the performed studies illustrate the importance (and limitations) of enclosing several molecular scaffolds in one molecular entity to allow the modulation of multiple AD targets.
- Hiremathad, Asha,Chand, Karam,Esteves, A. Raquel,Cardoso, Sandra M.,Ramsay, Rona R.,Chaves, Sílvia,Keri, Rangappa S.,Santos, M. Amélia
-
p. 53519 - 53532
(2016/06/14)
-
- A Minimal, Unstrained S-Allyl Handle for Pre-Targeting Diels–Alder Bioorthogonal Labeling in Live Cells
-
The unstrained S-allyl cysteine amino acid was site-specifically installed on apoptosis protein biomarkers and was further used as a chemical handle and ligation partner for 1,2,4,5-tetrazines by means of an inverse-electron-demand Diels–Alder reaction. We demonstrate the utility of this minimal handle for the efficient labeling of apoptotic cells using a fluorogenic tetrazine dye in a pre-targeting approach. The small size, easy chemical installation, and selective reactivity of the S-allyl handle towards tetrazines should be readily extendable to other proteins and biomolecules, which could facilitate their labeling within live cells.
- Oliveira, Bruno L.,Guo, Zijian,Boutureira, Omar,Guerreiro, Ana,Jiménez-Osés, Gonzalo,Bernardes, Gon?alo J. L.
-
supporting information
p. 14683 - 14687
(2016/11/23)
-
- A step-by-step crystallization for preparing thio alkyl/alkenyl cysteine sulfoxide method
-
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.
- -
-
Paragraph 0053; 0054
(2017/05/26)
-
- New Tacrine Hybrids with Natural-Based Cysteine Derivatives as Multitargeted Drugs for Potential Treatment of Alzheimer's Disease
-
Alzheimer's disease (AD) is a devastating age-dependent neurodegenerative disorder. The main hallmarks are impairment of cholinergic system and accumulation in brain of beta-amyloid (Aβ) aggregates, which have been associated with oxidative damage and dyshomeostasis of redox-active biometals. The absence of an efficient treatment that could delay or cure AD has been attributed to the complexity and multifactorial nature of this disease. With this in mind and the recent interest on natural-based drugs, we have explored a set of natural-based hybrid compounds by conjugation of a tacrine moiety with an S-allylcysteine (garlic constituent) or S-propargylcysteine moiety aimed at improving the cholinergic system and neuroprotective capacity. The docking modeling studies allowed the selection of linkers to optimize the bimodal drug interaction with acetylcholinesterase enzyme (AChE) active site. The compounds were evaluated for some representative biological properties, including AChE activity and Aβ aggregation inhibition, as well as for their neuroprotective activity to Aβ- and ROS-induced cellular toxicity.
- Keri, Rangappa S.,Quintanova, Catarina,Chaves, Sílvia,Silva, Diana F.,Cardoso, Sandra M.,Santos, M. Amélia
-
p. 101 - 111
(2016/02/03)
-
- Design of α-S-Neoglycopeptides Derived from MUC1 with a Flexible and Solvent-Exposed Sugar Moiety
-
The use of vaccines based on MUC1 glycopeptides is a promising approach to treat cancer. We present herein several sulfa-Tn antigens incorporated in MUC1 sequences that possess a variable linker between the carbohydrate (GalNAc) and the peptide backbone. The main conformations of these molecules in solution have been evaluated by combining NMR experiments and molecular dynamics simulations. The linker plays a key role in the modulation of the conformation of these compounds at different levels, blocking a direct contact between the sugar moiety and the backbone, promoting a helix-like conformation for the glycosylated residue and favoring the proper presentation of the sugar unit for molecular recognition events. The feasibility of these novel compounds as mimics of MUC1 antigens has been validated by the X-ray diffraction structure of one of these unnatural derivatives complexed to an anti-MUC1 monoclonal antibody. These features, together with potential lack of immune suppression, render these unnatural glycopeptides promising candidates for designing alternative therapeutic vaccines against cancer.
- Rojas-Ocáriz, Víctor,Compa?ón, Ismael,Aydillo, Carlos,Castro-Lo?ez, Jorge,Jiménez-Barbero, Jesús,Hurtado-Guerrero, Ramón,Avenoza, Alberto,Zurbano, María M.,Peregrina, Jesús M.,Busto, Jesús H.,Corzana, Francisco
-
p. 5929 - 5941
(2016/07/23)
-
- S-ALLYLCYSTEINE PRODUCTION METHOD
-
PROBLEM TO BE SOLVED: To provide a method of producing S-allylcysteine conveniently in a short time. SOLUTION: The S-allylcysteine production method comprises a step of coexistence of alliin and cysteine in a solvent. COPYRIGHT: (C)2015,JPO&INPIT
- -
-
Paragraph 0032
(2016/12/16)
-
- IMPROVEMENTS IN OR RELATING TO ALLIUM EXTRACTS
-
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.
- -
-
Page/Page column 82; 83
(2015/02/02)
-
- Influence of α-methylation in constructing stapled peptides with olefin metathesis
-
Ring-closing metathesis is commonly utilized in peptide macro-cyclization. The influence of α-methylation of the amino acids bearing the olefin moieties has never been systematically studied. In this report, controlled reactions unambiguously indicate that α-methylation at the N-terminus of the metathesis sites is crucial for this reaction to occur. Also, we first elucidated that the E-isomers of stapled peptides are significantly more helical than the Z-isomers.
- Zhang, Qingzhou,Shi, Xiaodong,Jiang, Yanhong,Li, Zigang
-
p. 7621 - 7626
(2014/12/11)
-
- A new dipeptide isolated from the bulb of garlic
-
(R)-3-(allylthio)-2-((R)-3-(allylthio)-2-aminopropanamido)propanoic acid was isolated from the bulb of garlic, together with four known amino acids. Its structure was elucidated on the basis of 2D NMR and MS techniques. To the best of our knowledge, (R)-3-(allylthio)-2-((R)-3-(allylthio)-2-aminopropanamido) propanoic acid, which showed antibacterial activity against the Staphylococcus aureus antibiotic resistant strain, was the first example of dipeptide from garlic.
- Zhou, Mei-Yun,Wu, Zhao-Jun,Li, Wen-Qing,Hu, Xing-Peng,Yan, Rian,Ou, Shi-Yi,Zhou, Hua
-
p. 323 - 326
(2014/02/14)
-
- OLEFIN METATHESIS REACTIONS OF AMINO ACIDS, PEPTIDES AND PROTEINS CONTAINING ALLYL SULFIDE GROUPS
-
A method for the modification of an amino acid, protein or peptide is disclosed. The method comprises reacting a carbon-carbon double bond-containing compound with an amino acid, a protein or a peptide containing an allyl sulfide group in the presence of a catalyst which promotes olefin metathesis, to form a modified amino acid, protein or peptide. Preferred carbon-carbon double bond-containing compounds include carbohydrates.
- -
-
Page/Page column 10-11
(2012/07/27)
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- Role of allyl group in the hydroxyl and peroxyl radical scavenging activity of S-allylcysteine
-
S-Allylcysteine (SAC) is the most abundant compound in aged garlic extracts, and its antioxidant properties have been demonstrated. It is known that SAC is able to scavenge different reactive species including hydroxyl radical (?OH), although its potential ability to scavenge peroxyl radical (ROO?) has not been explored. In this work the ability of SAC to scavenge ROO? was evaluated, as well as the role of the allyl group (-S-CH2-CH=CH2) in its free radical scavenging activity. Two derived compounds of SAC were prepared: S-benzylcysteine (SBC) and S-propylcysteine (SPC). Their abilities to scavenge ?OH and ROO? were measured. A computational analysis was performed to elucidate the mechanism by which these compounds scavenge ?OH and ROO?. SAC was able to scavenge ?OH and ROO?, in a concentration-dependent way. Such activity was significantly ameliorated when the allyl group was replaced by benzyl or propyl groups. It was shown for the first time that SAC is able to scavenge ROO?.
- Maldonado, Perla D.,Alvarez-Idaboy, J. Raúl,Aguilar-González, Adriana,Lira-Rocha, Alfonso,Jung-Cook, Helgi,Medina-Campos, Omar Noel,Pedraza-Chaverrí, José,Galano, Annia
-
experimental part
p. 13408 - 13417
(2012/02/14)
-
- Catalytic dehydrative S-allylation of cysteine-containing peptides in aqueous media toward lipopeptide chemistry
-
Thiol-containing peptides and cysteine have been successfully S-allylated with various allyl alcohols in aqueous medium containing a catalytic amount of [CpRu- (η3-C3H5)(2-quinolinecarboxylato)]PF6. Quick and easy install of 2-propen-l-ol having a long-chain alkyl group at C(2) facilitates the synthesis of a new series of artificial lipopeptides, indicating a potential application to synthetic biology.
- Jaisankar, Parasuraman,Tanaka, Shinji,Kitamura, Masato
-
scheme or table
p. 1894 - 1897
(2011/06/24)
-
- Method Of Synthesizing S-Allyl-Cysteine Analogues And Their Therapeutic Application In Treating Myocardial Infarction
-
A pharmaceutical composition and methods of producing and application of the composition for treating myocardial infarction of a subject are disclosed. The pharmaceutical composition comprises a therapeutically effective amount of at least one synthesized compound selected from the group consisting of SEC, SPC, SBC, SPEC, SAC, SAMC, and SPRC, and a pharmaceutically acceptable carrier.
- -
-
Page/Page column 9
(2009/04/24)
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- Allyl sulfides are privileged substrates in aqueous cross-metathesis: Application to site-selective protein modification
-
Allyl sulfides undergo efficient cross-metathesis in aqueous media with Hoveyda-Grubbs second generation catalyst 1. The high reactivity of allyl sulfides in cross-metathesis was exploited in the first examples of cross-metathesis on a protein surface. S-Allylcysteine was incorporated chemically into the protein, providing the requisite allyl sulfide handle. Preliminary efforts to genetically incorporate S-allylcysteine into proteins are also reported. Copyright
- Lin, Yuya A.,Chalker, Justin M.,Floyd, Nicola,Bernardes, Goncalo J. L.,Davis, Benjamin G.
-
supporting information; experimental part
p. 9642 - 9643
(2009/02/04)
-
- S-allylcysteine scavenges singlet oxygen and hypochlorous acid and protects LLC-PK1 cells of potassium dichromate-induced toxicity
-
It has been found that S-allylcysteine (SAC), a garlic-derived compound, has in vivo and in vitro antioxidant properties. In addition, it is known that SAC is able to scavenge different reactive oxygen or nitrogen species including superoxide anion (O2{radical dot} -), hydrogen peroxide (H2O2), hydroxyl radical (OH{radical dot}), and peroxynitrite anion (ONOO-) although the IC5O values for each reactive species has not been calculated and the potential ability of SAC to scavenge singlet oxygen (1O2) and hypochlorous acid (HOCl) has not been explored. The purposes of this work was (a) to explore the potential ability of SAC to scavenge 1O2 and HOCl, (b) to further characterize the O2{radical dot} -, H2O2, OH{radical dot}, and ONOO- scavenging ability of SAC by measuring the IC50 values using in vitro assays, and (c) to explore the potential ability of SAC to ameliorate the potassium dichromate (K2Cr2O7)-induced cytotoxicity in LLC-PK1 cells in which oxidative stress is involved. The scavenging activity was compared against the following reference compounds: N-acetylcysteine for O2{radical dot} -, sodium pyruvate for H2O2, dimethylthiourea for OH{radical dot}, lipoic acid and glutathione for 1O2, lipoic acid for HOCl, and penicillamine for ONOO-. It was found that SAC was able to scavenge concentration-dependently all the species assayed with the following IC5O (mean ± SEM, mM): O2{radical dot} - (14.49 ± 1.67), H2O2 (68 ± 1.92), OH{radical dot} (0.68 ± 0.06), 1O2 (1.93 ± 0.27), HOCl (2.86 ± 0.15), and ONOO- (0.80 ± 0.05). When the ability of SAC to scavenge these species was compared to those of the reference compounds it was found that the efficacy of SAC (a) to scavenge O2{radical dot} -, H2O2, OH{radical dot}, and ONOO- was lower, (b) to scavenge HOCl was similar, and (c) to scavenge 1O2 was higher. In addition, it was found that SAC was able to prevent K2Cr2O7-induced toxicity in LLC-PK1 cells in culture. It was showed for the first time that SAC is able to scavenge 1O2 and HOCl and to ameliorate the K2Cr2O7-induced toxicity.
- Medina-Campos, Omar Noel,Barrera, Diana,Segoviano-Murillo, Sabina,Rocha, Diana,Maldonado, Perla D.,Mendoza-Patino, Nicandro,Pedraza-Chaverri, Jose
-
p. 2030 - 2039
(2008/03/12)
-
- Design and synthesis of new bicyclic diketopiperazines as scaffolds for receptor probes of structurally diverse functionality
-
Diketopiperazines (DKPs) are a common motif in various biologically active natural products, and hence they may be useful scaffolds for the rational design of receptor probes and therapeutic agents. We constructed a new bicyclic scaffold that combines a D
- Besada, Pedro,Mamedova, Liaman,Thomas, Craig J.,Costanzi, Stefano,Jacobson, Kenneth A.
-
p. 2016 - 2025
(2007/10/03)
-
- Potent inhibitors of the hepatitis C virus NS3 protease: Design and synthesis of macrocyclic substrate-based β-strand mimics
-
The virally encoded NS3 protease is essential to the life cycle of the hepatitis C virus (HCV), an important human pathogen causing chronic hepatitis, cirrhosis of the liver, and hepatocellular carcinoma. The design and synthesis of 15-membered ring β-strand mimics which are capable of inhibiting the interactions between the HCV NS3 protease enzyme and its polyprotein substrate will be described. The binding interactions between a macrocyclic ligand and the enzyme were explored by NMR and molecular dynamics, and a model of the ligand/enzyme complex was developed.
- Goudreau, Nathalie,Brochu, Christian,Cameron, Dale R.,Duceppe, Jean-Simon,Faucher, Anne-Marie,Ferland, Jean-Marie,Grand-Maitre, Chantal,Poirier, Martin,Simoneau, Bruno,Tsantrizos, Youla S.
-
p. 6185 - 6201
(2007/10/03)
-
- In vitro biogeneration of pure thiosulfinates and propanethial-S-oxide
-
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.
- Shen, Cunxi,Parkin, Kirk L.
-
p. 6254 - 6260
(2007/10/03)
-
- Diastereoselective synthesis of alliin by an asymmetric sulfur oxidation
-
L-(+)-Alliin (7) has been synthesized from S-allyl-L-cysteine (3) by an asymmetric sulfur oxidation using tetraisopropyl-ortho-titanate [Ti(O-iPr)4] in equimolar amounts. Chirality of the resulting sulfoxide was guided by either (+)- or (-)diethyl tartrate as chiral auxiliary which led to the (-)- or (+)- isomer of L-alliin (7, 8), respectively. To allow this type of oxidation, the amino acid functions of 3 were protected by a tert.-butoxycarbonyl- and a 9- fluorenylmethyl group. Alternatively, an enzyme catalysed asymmetric sulfur oxidation by cyclohexanone oxygenase was carded out. The products were investigated by 1R, MS and NMR spectroscopy. The ratio between the diastereomers 7 and 8 was determined by HPLC. Also IR spectroscopy allowed an estimation of the approximate ratio 7/8.
- Koch,Keusgen, Michael
-
p. 668 - 671
(2007/10/03)
-
- PURIFICATION AND PROPERTIES OF β-CYANO-L-ALANINE SYNTHASE FROM SPINACIA OLERACEA
-
β-Cyano-L-alanine synthase was purified ca 6200-fold to homogeneity from the leaves of spinach (Spinacia oleracea).The purified enzyme has an apparent Mr of 60 000 and can be dissociated into identical subunits of Mr 30 000.The subunits each contain one molecule of pyridoxal 5'-phosphate.The Km value is 2.3 mM for L-cysteine and 0.73 mM for cyanide. β-Cyano-L-alanine synthase from S. oleracea also catalyses the formation of some S-substituted L-cysteines and some heterocyclic β-substituted alanines from L-cysteine or O-acetyl-L-serine.The specificity of these additional catalytic activities of the purified enzyme are compared with those of cysteine synthase purified from the same plant, and with those of β-cyano-L-alanine synthase purified from other sources.Some other properties, including the amino acid composition of the purified enzyme, are also described. - Key Word Index: Spinacia oleracea; Chenopodiaceae; spinach; β-cyano-L-alanine synthase; cysteine synthase; enzyme purification; amino acid composition; L-cysteine; O-acetyl-L-serine; β-cyano-L-alanine; heterocyclic β-substituted alanines.
- Ikegami, Fumio,Takayama, Kyoko,Tajima, Chiho,Murakoshi, Isamu
-
p. 2011 - 2016
(2007/10/02)
-
- ENZYMATIC SYNTHESIS OF THE NEUROEXCITATORY AMINO ACID QUISQUALIC ACID BY CYSTEINE SYNTHASE
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Key Word Index - Quisqualis indica var. villosa; Combretaceae; cysteine synthase; isoenzyme; enzyme purification; biosynthesis; heterocyclic β-substituted alanines; quisqualic acid; O-acetyl-L-serine; cysteine.Purification of cysteine synthase from the leaves of Quisqualis indica var. villosa reveals the presence of two forms of this enzyme, separated by chromatography on DEAE-Sephadex A-50.Isoenzyme A was purified 10 000-fold and had a specific activity of 10.8 U/mg protein.Isoenzyme B was purified 460-fold with a specific activity of 0.49 U/mg protein.Both isoenzymes have the same Mrs (58 000) and dissociate into identical subunits (Mr 29 000).The Km value of isoenzyme A is 1.9 mM for O-acetyl-L-serine and 59 μM for sulphide, while that of isoenzyme B is 7.1 mM for O-acetyl-L-serine and 4.0 mM for 3,5-dioxo-1,2,4-oxadiazolidine.Both isoenzymes catalyse the formation of cysteine from O-acetyl-L-serine and hydrogen sulphide, but only isoenzyme B catalyses the formation of L-quisqualic acid.Other significant differences occur in the substrate specificity of the two isoenzymes.Some properties of the purified cysteine synthase isoenzymes are also described.
- Murakoshi, Isamu,Kaneko, Masakazu,Koide, Chiharu,Ikegami, Fumio
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p. 2759 - 2764
(2007/10/02)
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- RELATION BETWEEN THE STRUCTURE OF ALLIIN ANALOGUES AND THEIR INHIBITORY EFFECT ON PLATELET AGGREGATION
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Key Word Index - Alliin; S-allyl-L-cysteine sulphoxide; allicin; dihydroalliin; platelet aggregation inhibitors. - Alliin analogues have been synthesized and tested for their inhibitory activity on platelet aggregation.It is found that only allicin, the S-oxodiallyl disulphide, has a strong inhibitory effect, comparable to that of alliin, while all the other tested compounds do not show any inhibitory effect even at concentrations of 10-3 M.
- Liakopoulou-Kyriakides, M.
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p. 1593 - 1594
(2007/10/02)
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- Synthesis of L-Cysteine and Its Analogues by Intact Cells Containing Cysteine Desulfhydrase
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Cysteine desulfhydrase catalyzes β-replacement, the reverse reaction of α,β-elimination, as well as α,β-elimination.These reactions were studied with intact cells of Aerobacter aerogenes I-3-2 and Aerobacter cloacae IFO 12009 containing cysteine desulfhydrase.L-Cysteine and its analogues were synthesized by replacement and reverse reactions using intact cells. β-Chloro-L-alanine, L-cysteine, S-methyl-L-cysteine, S-allyl-L-cysteine and L-serine were used as substrates together with hydrogen sulfide and methyl mercaptan to synthesize L-cysteine and S-methyl-L-cysteine via replacement reaction by intact cells.L-Cysteine synthesized from β-chloro-L-alanine was confirmed to be entirely in L-form after isolation and identification of the product.The reverse reaction for synthesis of L-cysteine and S-methyl-L-cysteine from hydrogen sulfide or methyl mercaptan, pyruvate and ammonia was also catalyzed by intact cells. β-Chloro-L-alanine was found to be the best substrate for synthesis of L-cysteine and S-methyl-L-cysteine by β-replacement reaction.
- Ohkishi, Haruyuki,Nishikawa, Daikichiro,Kumagai, Hidehiko,Yamada, Hideaki
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p. 259 - 264
(2007/10/02)
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