通过α-甲基烷基化反应合成Sulfoximine类衍生物

从Sulfoximine A出发,选取对甲氧基苄基(PMB)为N-保护基,通过α-甲基的烷基化反应合成了一系列新的Sulfoximine类衍生物,其结构经1HNMR确证。

Synthesis,Crystal Structure and Biological Activity of N-cyanosulfoximine Derivative Containing 1,2,3-Thiadiazole

The title compound N-cyanosulfoximine derivative containing 1,2,3-thiadiazole （C6HsN4OS2, Mr = 216.28） has been synthesized using 4-（chloromethyl）-5-methyl-1,2,3-thiadiazole as the starting material, and its structure was characterized by IR, 1H NMR, HRMS, elemental analysis and single-crystal X-ray diffraction. The crystal of the title compound belongs to orthorhombic, space group Pna21 with a = 14.730（6）, b = 5.478（2）, c = 22.619（9） A, Z = 8, V = 1825.0（13） A3, Dc = 1.574 g/cm3,/a = 0.547 mm-1, F（000） = 896, R = 0.0767 and wR （I〉 2o（/）） = 0.2064. X-ray analysis indicates that in this crystal double enantiomers are found as the basically asymmetrical unit and interactions between S（1）...N（3）, S（3）...N（4） and S（3）...N（7） are observed. This kind of interactions extends the molecules into a one-dimensional double chain. The preliminary biological test showed that the title compound had insecticidal activity against Myzus persicae in a certain degree and also presented moderate potential bioactivity against tobacco mosaic virus （TMV）.

Preclinical evaluation of azathioprine plus buthionine sulfoximine in the treatment of human hepatocarcinoma and colon carcinoma

AIM: To evaluate the efficacy and the safety of azathioprine (AZA) and buthionine sulfoximine (BSO) bylocalized application into HepG2 tumor in vivo.METHODS: Different hepatoma and colon carcinoma cell lines (HepG2, HuH7, Chang liver, LoVo, RKO, SW-48, SW-480) were grown in minimal essencial medium supplemented with 10% fetal bovine serum and 1% antibiotic/antimycotic solution and maintained in a humidified 37 ℃ incubator with 5% CO2. These cells were pretreated with BSO for 24 h and then with AZA for different times. We examined the effects of this combination on some proteins and on cellular death. We also studied the eff icacy and the safety of AZA (6 mg/kg per day) and BSO (90 mg/kg per day) in HepG2 tumor growth in vivo using athymic mice. We measured safety by serological markers such as aminotransferases and creatine kinase.RESULTS: The in vitro studies revealed a new mechanism of action for the AZA plus BSO combination in the cancer cells compared with other thiopurines (6-mercaptopurine, 6-methylmercaptopurine, 6-thioguanine and 6-methylthioguanine) in combination with BSO. The cytotoxic effect of AZA plus BSO in HepG2 cells resulted from necroptosis induction in a mitochondrial-dependent manner. From kinetic studies we suggest that glutathione (GSH) depletion stimulates c-Jun amino-terminal kinase and Bax translocation in HepG2 cells with subsequent deregulation of mitochondria (cytochrome c release, loss of membrane potential), and proteolysis activation leading to loss of membrane integrity, release of lactate dehydrogenase and DNA degradation. Some of this biochemical and cellular changes could be reversed by N-acetylcysteine (a GSH replenisher). In vivo studies showed that HepG2 tumor growth was inhibited when AZA was combined with BSO.CONCLUSION: Our studies suggest that a combination of AZA plus BSO could be useful for localizedtreatment of hepatocellular carcinoma as in the currently used transarterial chemoembolization method.

Catalytic enantioselective N-silylation of sulfoximine

A rhodium/diphosphine-catalyzed asymmetric cross-dehydrogenative coupling between sulfoximines and dihydrosilanes has been achieved. This is the first report on the enantioselective N-silylation of sulfoximines. The protocol gives access to a variety of Si-stereogenic N-silylated sulfoximines in decent yield(up to 99%) with excellent stereoselectivity(up to 99%), featuring high atom economy, and a cleaner manner with H2as the sole byproduct. The obtained bis-Si-stereogenic monohydrosilane product can be further converted into the corresponding chiral polymer with pendant sulfoximine groups.

Discovery of Novel Anthranilic Diamide Derivatives Bearing Sulfoximine Group as Potent Insecticide Candidates

The fall armyworm,Spodoptera frugiperda(S.frugiperda),represents the most resistant insect species and poses serious threat to grain yield.Chlorantraniliprole(CHL),which targets the ryanodine receptors(RyRs)in insects,has demonstrated the efficacy in controlling S.frugiperda.Nevertheless,this has led to emerging resistance in several countries.To counter this resistance,a viable approach involves the development of novel compounds that bind against RyRs via distinct binding sites or modes.In this study,a series of 22 novel anthranilic diamide derivatives was designed and synthesized,and their insecticidal activities were evaluated.Most of these derivatives showed moderate to good insecticidal activity against S.frugiperda and Mythimna separata.Time-lapse fluorescence measurements of endoplasmic reticulum luminal calcium revealed that most derivatives elicited cellular responses similar as CHL when assessed on HEK293 cells expressing S.frugiperda ryanodine receptors(SfRyRs).The mode of action of compound 13a was studied and verified on the isolated neurons by calcium imaging technique.Finally,molecular docking analysis was employed to predict the binding mechanism of compound 13a against SfRyRs.Overall,these novel diamide derivatives hold promise as a valuable resource for guiding the future design of insecticidal compounds targeting RyRs.

Multipurpose sulfoximine-mediated radicalγ-heteroarylation of unactivated C(sp^(3))–H bonds

A conceptually novel,trifunctional sulfoximine-mediatedγ-functionalization of unactivated C(sp^(3))–H bonds has been achieved.The reaction is initiated by the photo-induced homolytic cleavage of an N–S bond in the absence of photosensitizer,and proceeds sequentially through a cascade of 1,5-hydrogen atom transfer,1,4-functional group migration,desulfoximination and a Minisci reaction.A major feature of this approach is the use of sulfoximine as a traceless directing group.Other positive properties include mild conditions,simple operation,exclusive site-selectivity,high product diversity and the avoidance of additional photosensitizers.The protocol provides a new reaction mode for HAT-induced C(sp^(3))–H functionalization,and allows a much broader chemical space for sulfoximine studies.

Cp*Rh/Ag catalyzed C–H activation/cyclization sequences of NH-sulfoximines to fused aza-polyheterocycles under gentle conditions

Disclosed herein is a novel Rh/Ag co-catalyzed S=NH directed C–H activation and C–H/N–H bond functionalization protocol of free NH-sulfoximines with hypervalent iodonium ylides.With the aid of AgOTf,these C–H functionalization/cyclization sequences could be achieved at room temperature conditions.The reaction employed EtOH as a“green”solvent and low catalyst loading was required under an oxygen/water-insensitive condition.Under this mild protocol,a wide range of polyheterocyclic sulfoximines bearing fused saturated carbo(hetero)cycles are readily prepared,even toward a complex pharmaceutical Folliculin analog.

Visible light promoted synthesis of N-aroylsulfoximines by oxidative C–H acylation of NH-sulfoximines

The visible light-promoted synthesis of N-aroylsulfoximines has been accomplished via an oxidative dehydrogenative coupling at room temperature under air without the addition of a photosensitizer, metal catalyst, or base. This process exhibits good functional group tolerance, allows facile isolation and purification, and affords N-aroylsulfoximines with high efficiency. The efficiency of the newly developed protocol is described in detail with 27 examples with yields ranging from 80% to 96%.Furthermore, the chirality of the NH-sulfoximine is completely maintained in the desired N-aroylsulfoximine product(>99% ee).

Difluoromethyl 2-Pyridyl Sulfoximine:A Stereoselective Nucleophilic Reagent for Difluoro(aminosulfinyl)methylation and Difluoro(aminosulfonyl)methylation

1,1-Difluorinated sulfonamides are known to have better anti-inflammatory activity and enzyme inhibitory potency than their nonfluorinated counterparts.Two geminal fluorine atoms cause electronic perturbation of the nearby polar groups enhanced the biological activity of the 1,1-difluorinated sulfonamides.However,because methods for their stereoselective synthesis are scarce,such entities remain entirely unexplored.Here,we outline an efficient method for the stereoselective introduction of the difluoro(aminosulfonyl)methyl group(CF_(2)SO_(2)NH_(2))into carbonyls,imines,and alkyl halides with a new(R)-2-pyridyl difluoromethyl sulfoximine reagent,which provides a unique solution for the synthesis of chiralα,α-difluorinated sulfonamides with a quaternary stereocenter.Its potency is illustrated by the synthesis of fluorinated analogues of bioactive compounds such as 2-OH-SA,an antagonist for the GABA_(B)receptor in guinea pig ileum,and the late-stage modification of complex molecules such as haloperidol,ebastine,cholesterol,and(+)-δ-tocopherol derivatives.Stereoselective difluoro(aminosulfinyl)methylation to yield chiral sulfinylamides is presented,showcasing other uses of this new reagent.

Study on effect of BSO on esophageal cancer cell line TE-1

Objective: The aim of the study was to investigate the sensitizing effect of buthionine sulfoximine (BSO) and radiation on esophageal cancer cell line TE-1. Methods: Methyl thiazolyl tetrazolium (MTT) assay was used to observe the inhibition of BSO and radiation on cell proliferation, and to investigate the sensitizing effect of BSO on esophageal cancer cell line TE-1. Flow cytometry (FCM) was used to observe the effect of BSO and radiation on cell apoptosis and cycle. Reverse transcription polymerase chain reaction (RT-PCR) and Western blot were used to observe the effect of BSO on manganese superoxide dismutase (MnSOD) mRNA and protein expression. Results: BSO could inhibit the proliferation of TE-1 esophageal cancer cells, and had significant dose- and time-dependent radiosensitizing effects on TE-1 esophageal cancer cells. After the combined effects of BSO and radiation on TE-1 cells, the rate of apoptosis and G2/M phase proportion increased significantly, and MnSOD mRNA and protein expression decreased. Conclusion: BSO may reduce MnSOD mRNA and protein expression by affecting TE-1 cell cycle, thus inhibiting and inducing the apoptosis of esophageal cancer cells and enhancing the killing effect of the radiation on esophageal cancer cells.

The timing and extent of intraosseous hypoxia in the oxidative stress-induced rat osteonecrosis model

Using a rat oxidative stress-induced femoral head osteonecrosis model, we determined the presence/ absence and timing of the generation of hypoxia in the femoral head. DL-Buthionine-(S,R)-sulfoximine (BSO) 500 mg/kg was administered intraperitoneally to male Wistar rats. The rats were killed at 1, 3, 6, 12 hours, and 1, 3, 5 days after BSO administration, and the bilateral femora were removed. A group not administered BSO (control group) was also studied (each group n = 5). In the femoral heads of each group, the expression of hypoxia-inducible factor-1 alpha (HIF-1α) as an index of hypoxia was confirmed by the Western blot method, and quantified using analytical software. In the femoral head increased HIF-1α expression was found in all groups from 1 hour after BSO administration (p < 0.05). In particular, in all specimens of the group 3 hours after BSO administration the most intense expression of HIF-1α amounting to about 13-fold of that of control group was noted (p < 0.001). The present results suggested that in the extremely short period of 3 hours after BSO administration hypoxia severe enough to cause osteonecrosis was induced by oxidative stress in the rat femoral head.

Strain-promoted S-arylation and alkenylation of sulfinamides using arynes and cyclic alkynes

The conversion of commercially available chiral sulfinamides into pharmaceutically useful chiral sulfoximines via direct SIVfunctionalization is synthetically attractive but challenging due to the competitive reaction of N-functionalization. Herein, we disclose a novel strain-release strategy to access stereospecific and chemoselective SIV-arylation and alkenylation of sulfinamides using arynes and strained cyclic alkynes. This method tolerates an unprecedented chemical diversity of functional groups attached to the nitrogen center(N-R). The origin of the high SIV-selectivity is elucidated by density functional theory calculations, suggesting a stepwise mechanism for the aryne substrates and a concerted mechanism for the cyclic alkynes.

Arsenic trioxide induces multiple myeloma cell apoptosis via disruption of mitochondrial transmembrane potentials and activation of caspase-3

OBJECTIVE: To investigate the response of multiple myeloma (MM) cells to arsenic trioxide (As2O3) and their possible mechanisms. METHODS: Two MM-derived cell lines RPMI8226 and U266 cells were used as in vitro models. Cell apoptosis was assessed by morphology, flow cytometry, and DNA gel electrophoresis. Mitochondrial transmembrane potentials (delta psi m) were evaluated by measuring cellular Rhodamine 123 staining intensity. Protein expression was analyzed using Western blot. RESULTS: Zero point one to 0.5 mumol/L As2O3 inhibited cell proliferation and 2.0 mumol/L As2O3 induced cell apoptosis, while 1.0 mumol/L As2O3 inhibited proliferation with a weak degree of apoptosis induction in RPMI8226 and U266 cell lines. As2O3-induced apoptosis was accompanied by mitochondrial transmembrane potentials (delta psi m) collapse and caspase-3 activation in the presence of intact membrane. Glutathione depleter buthionine sulfoximine enhanced, while disulfide bond-reducing agent dithiothreitol partially antagonized As2O3-induced delta psi m collapse and apoptosis in MM cells. All-trans retinoic acid (ATRA) could also induce apoptosis in RPMI8226 cells, but it did not show any cooperative effects with As2O3. CONCLUSION: As2O3 exerts apoptosis-inducing and growth-inhibiting effects on MM cells, and mitochondrium is a pivotal and common target of As2O3 for apoptosis induction.

Design, Synthesis, Structure-Activity Relationship and Insecticidal Activities of Trifluoromethyl-Containing Sulfiliminyl and Sulfoximinyl Phthalic Acid Diamide Structure

Due to a novel mode action,low toxicity to mammals and low residue characteristics,phthalic acid diamides have aroused considerable interests in agricultural chemistry.With introduction of N-cyano,N-trifluoroacetyl,N-carbamoylsulfiliminyl and sulfoximinyl substituents into phthalamides,12 novel derivatives containing trifluoromethyl moiety were designed and synthesized.All title compounds were characterized by ^(1)H NMR and high-resolution mass spectrometry.The preliminary results of biological activity assessment indicated that some title compounds exhibited moderate to good insecticidal activities against oriental armyworm(Pseudaletia separata Walker).In particular,Va gave higher activity against oriental armyworm and diamondback moth.The present work reported that the new trifluoromethylated diamides incorporating N-trifluoroacetylsulfoximinyl moieties are potential lead compounds for further structure optimization,providing some insight into the relating structure-activity relationship.

Nucleophilic Difluoro(phenylsulfonimidoyl)methylation of Unactivated Alkyl Bromides with PhSO(NTBS)CF_(2)H: Facile Entry into gem-Difluoroalkenes

An efficient nucleophilic difluoro(phenylsulfonimidoyl)methylation of unactivated primary alkyl bromides with PhSO(NTBS)CF_(2)H has been developed.It is particularly remarkable that,when 1.5 equiv.of alkyl bromides are used,the substitution products are obtained in moderate to excellent yields.The prepared difluoro(phenylsulfonimidoyl)methylated alkanes can be readily transformed to gem-difluoroalkenes via base-mediatedβ-elimination reaction.

Design, Synthesis, Biological Evaluation and SARs of Novel N-Substituted Sulfoximfnes as Potential Ryanodine Receptor Modulators

The sulfoximine group has been evaluated as a pharmacophore. Introducing the sulfoximine structure into medicinal compounds as exciting motifs has brought opportunities in drug discovery. In order to develop new ryanodine receptor （RyR） modulators, a series of phthalamides containing sulfoximine derivatives were designed, synthesized, and evaluated against oriental armyworm and diamondback moth for their insecticidal activities. These studies helped to elucidate the electronic and structural requirements around the sulfoximine motif for insecticidal activity. All new structures were synthesized and characterized by ^1H NMR, ^13C NMR, HRMS and bioassay and a preliminary structure-activity relationship （SAR） was discussed. The biological assessment indicated that most title compounds showed good to excellent larvicidal activities. Compounds la, le, and If gave excellent insecticidal activity against oriental armyworm, which showed 100% larvicidal activity at 0.5 mg/L. All compounds showed 100% larvicidal activity at 0.1 mg/L against diamondback moth. In particular, the larvicidal activities of le, If, and lh at 0.0001 mg/L were 50%, 20%, and 40%, respectively, reaching an activity as high as that of the commercial flubendiamide （40%, 0.0001mg/L）. Therefore, Ia, Ie, If and Ih could be considered as new lead structures for the development of new ryanodine receptor （RyR） modulators.