Yuxiu Liu

Nankai University, T’ien-ching-shih, Tianjin Shi, China

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Publications (49)137.91 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND Phenanthroindolizidine alkaloid antofine and its analogues have excellent antiviral activity against tobacco mosaic virus (TMV). To simplify the structure and the synthesis hardness of phenanthroindolizidine alkaloid, a series of phenanthrene–containing N-heterocyclic compounds 1–33 were designed and synthesized based on the intermolecular interaction of antofine and TMV RNA and systematically evaluated for their anti-TMV activity.RESULTMost of these compounds exhibited good to reasonable anti-TMV activity. The optimum compounds 5, 12 and 21 displayed higher activity than the lead compound antofine and commercial ribavirin. Compound 12 was chosen for the field trials of antiviral efficacy against TMV, and found to exhibit better activity than control plant virus inhibitors. Compounds 5 and 12 were chosen for mode of action studies. The changes of fluorescence intensity of 5 and 12 on separated TMV RNA showed that these small molecules can also bind to TMV RNA, but the mode is much different from that of antofine.CONCLUSION The compounds combining phenanthrene and N-heterocyclic ring could maintain the anti-TMV activity of phenanthroindolizidines, but their modes of action are different from that of antofine. Present study lays a good foundation for us to find more efficient anti-plant virus reagents.
    Pest Management Science 03/2015; DOI:10.1002/ps.4008 · 2.74 Impact Factor
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    ABSTRACT: A concise method for the synthesis of 1,2-fused tricyclic indole scaffolds by domino cyclization involving a Pd-catalyzed Sonogashira coupling, indole cyclization, regio- and chemoselective N-1 acylation, and 1,4-Michael addition is reported. This method provides straightforward access to tetrahydro[1,4]diazepino[1,2-a]indole and hexahydro[1,5]diazocino[1,2-a]indole scaffolds. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
    Chemistry - A European Journal 02/2015; 21(14). DOI:10.1002/chem.201406617 · 5.70 Impact Factor
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    ABSTRACT: A series of tylophora alkaloids and their derivatives (1–38) were synthesized and systematically bioassayed for their anti-HIV activity for the first time. The results revealed that most of these alkaloids possess good HIV inhibitory effect. Especially, compounds 1, 4 and 25 displayed low nanomolar levels of anti-HIV activity (inhibitory effect at 50 nM: 1: 71%; 4: 60%; 25: 64%), which is about similar to that of the first HIV inhibitor AZT (inhibitory effect at 50 nM: 70%) and slightly lower than that of the first HIV integrase inhibitor MK-0518 (inhibitory effect at 50 nM: 82%). Present studies provide fundamental support for the development of tylophora alkaloids as novel HIV inhibitors.
    Letters in Drug Design &amp Discovery 02/2015; 12(4):277-283. DOI:10.2174/1570180811666141009235124 · 0.96 Impact Factor
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    ABSTRACT: A concise and efficient enantioselective strategy to synthesize two typical phenanthroindolizidine alkaloids, 14-hydroxyantofine and antofine, was developed, featuring an asymmetric deprotonation/diastereoselective carbonyl addition sequence during which the formation of a chiral C-13a center and connection of pyrrolidine and phenanthrene moieties were achieved efficiently in one step. The absolute configuration of the C-13a stereocenter can be delicately controlled by using different enantiomers of sparteine, both of which are commercially available.
    ChemInform 12/2014; 45(49). DOI:10.1002/chin.201449203
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    ABSTRACT: A series of aromatic gossypol Schiff bases have been successfully synthesized via a feasible chemical modification. The antiviral activity against tobacco mosaic virus (TMV) of these gossypol Schiff bases has been tested for the first time. The bioassay studies indicated most of these derivatives exhibited excellent anti-TMV activity, in which o-trifluoromethylaniline Schiff base (19) displayed the best antiviral activities. Furthermore, compound 19 exhibited an eminent anti-TMV effect in the field and low toxicity to mice. These results suggest it is a promising candidate for the inhibitor of plant virus.
    Journal of Agricultural and Food Chemistry 11/2014; 62(46). DOI:10.1021/jf504411g · 3.11 Impact Factor
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    ABSTRACT: Copper-mediated intramolecular trifluoromethylation of N-phenylcinnamamides coupled with cyclization and dearomatization was used to construct various trifluoromethylated 1-azaspiro[4.5]decanes in moderate to high yields and with excellent regioselectivity and diastereoselectivity.
    Organic Letters 11/2014; 46(18). DOI:10.1021/ol502921a · 6.32 Impact Factor
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    ABSTRACT: According to our previous research on the antiviral activity of β-carboline and tetrahydro-β-carboline derivatives, using (1S,3S)-1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carbohydrazide (1) as a lead compound, series of novel tetrahydro-β-carboline derivatives containing acylhydrazone moiety were designed, synthesized, and first evaluated for their biological activities. Most of these compounds exhibited excellent antiviral activity both in vitro and in vivo. The in vivo inactivation, curative, and protection activities of compounds 8, 9, 12, 16, 28, 29, and 30 were much higher than that of ribavirin (37.6%, 39.4%, and 37.9% at 500 μg/mL) and the lead compound (40.0%, 42.3%, and 39.6% at 500 μg/mL). Especially, the in vitro and in vivo activities of compound 16 (36.9%, 33.6%, 30.2%, and 35.8%) at 100 μg/mL, which were very close to that of ribavirin (40.0% for in vitro activity) at 500 μg/mL. Compounds 9 and 29 were chosen for the field trials of antiviral efficacy against TMV (tobacco mosaic virus); the results exhibited that both compounds, especially compound 29, showed better activities than control plant virus inhibitors. At the same time, the fungicidal results showed that compounds 6, 9, and 11 exhibited good fungicidal activities against 14 kinds of phytopathogens. Additionally, compounds 3 and 23 exhibited moderate insecticidal activity against the four tested species of insects.
    Journal of Agricultural and Food Chemistry 10/2014; 62(41). DOI:10.1021/jf503794g · 3.11 Impact Factor
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    ABSTRACT: To investigate the alkyl analog of insecticide chlorfenapyr, two series of 2-alkyl-4-bromo-5-(trifluoromethyl)pyrrole-3-carbonitriles were synthesized with a cycloaddition as the key step. The target products were characterized by H-1-NMR spectroscopy, elemental analysis, or HRMS. The insecticidal, herbicidal, and antifungal activities of the target compounds were evaluated and found that these compounds did not show much insecticidal activity, but compounds 4, 10, and 11 had very good fungicidal activities against Alternaria solani and Fusarium oxysporum. Moreover, compound 4 had an outstanding inhibition effect against pigweed.
    Journal of Heterocyclic Chemistry 09/2014; 51(5):1410-1414. DOI:10.1002/jhet.1835 · 0.87 Impact Factor
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    ABSTRACT: Based on interaction of antofine and TMV RNA, a series of phenanthrene and alkylamine chain containing antofine derivatives 1-41 were designed, synthesized and systematically evaluated for their antiviral activity against TMV. The results showed that most of these compounds exhibited good to excellent anti-TMV activity, which indicated that the "D", "E" rings of antofine may not be indispensable. Phenanthrene is important for these compounds but not the more the better. Phenanthrene, benzene rings and alkylamine chain containing compounds exhibited good antiviral activity. The optimum compounds 10, 18 and 19 displayed higher activity than precursor antofine and commercial Ribavirin, thus emerged as new lead compounds. The novel concise structure provides another new template for antiviral studies.
    Journal of Agricultural and Food Chemistry 08/2014; 62(43). DOI:10.1021/jf5028894 · 3.11 Impact Factor
  • Chaojie Li, Yuxiu Liu, Qingmin Wang
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    ABSTRACT: A metal-free, environment friendly, easy-to-operate, and efficient method for the semisynthesis of sophocarpine from matrine has been developed in an overall yield of 91%. The route features a controllable and efficient oxidation of thioether to sulfoxide by 2-iodoxybenzoic acid (IBX) in water.
    Tetrahedron Letters 07/2014; 55(4):950–953. DOI:10.1002/chin.201427214 · 2.39 Impact Factor
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    ABSTRACT: On the basis of the structures of chlorfenapyr and dioxapyrrolomycin, a series of 2-benzylpyrroles with a hydroxyl, an alkyloxy, an acyloxy, an alkylsulfanyl, or an oxime moiety at the α-position of benzyl were designed and synthesized. Their insecticidal, acaricidal, and fungicidal activities were extensively investigated. The structure–activity relationship showed that benzylpyrroles bearing shorter α-alkyloxy groups gave better activities against most of the insect species; the alkylation of pyrrole usually gave increased activity. Among all compounds, (4-bromo-2-(α-(2,2,2-trifluoroethoxy)-4-chlorobenzyl)-1-(ethoxymethyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile) (5′j) exhibited the most outstanding insecticidal activities against oriental armyworm (IC50 = 10 mg L–1), diamondback moth (0.07 mg L–1), corn borer (50 mg L–1), and mosquito (0.04 mg L–1), which are very close to those of chlorfenapyr (5, 0.08, <25, and <0.025 mg L–1, respectively). In addition, some compounds also exhibited a broad or selective fungicidal spectrum.
    Journal of Agricultural and Food Chemistry 06/2014; 62(26):6072–6081. DOI:10.1021/jf501377t · 3.11 Impact Factor
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    ABSTRACT: Copper-catalyzed intramolecular trifluoromethylation of N-benzylacrylamides coupled with dearomatization was achieved and used to regiospecifically construct a variety of trifluoromethylated 2-azaspiro[4.5]decanes bearing adjacent quaternary stereocenters under mild conditions in moderate to excellent yields.
    ChemInform 06/2014; 45(50). DOI:10.1021/ol501054c
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    ABSTRACT: An efficient method to prepare 1'H-spiro[indoline-3,3'-quinoline]-2',4'-diones and their trifluoromethylated products was developed via a palladium-catalyzed Sonogashira coupling/Wacker-type oxypalladation/cyclization cascade reaction. The amount of water in the reaction system played an important role in the in situ trifluoromethylation reaction, and the trifluoromethylation exhibited excellent molecular self-induced stereoselectivity.
    ChemInform 06/2014; 16(12). DOI:10.1021/ol501246f
  • Ling Li, Yuxiu Liu, Qingmin Wang
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    ABSTRACT: A practical and scalable route was developed for the total synthesis of gossypol to allow for the construction of dozens of gossypol derivatives. tBuO2Ac was found to be a highly efficient oxidant for the polymerization of hemigossypol through a biosynthetic process under nonenzymatic conditions to give gossypol. Hemigossypol was synthesized on a gram scale by starting from commercially available carvacrol and dimethyl succinate and using a Stobbe condensation, an electrophilic cyclization, and the Michael addition of ortho-quinone methide as key steps.
    ChemInform 05/2014; 45(21). DOI:10.1002/chin.201421243
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    ABSTRACT: A series of 7-methoxycryptopleurine derivatives 2–23 were prepared and evaluated for their antiviral activity against tobacco mosaic virus (TMV) for the first time. The bioassay results showed that most of these compounds exhibited excellent in vivo anti-TMV activity, of which 7-methoxycryptopleurine salt derivatives 16, 19 and 23 displayed significantly higher activity than 7-methoxycryptopleurine (1) and commercial Ribavirin and Ningnanmycin. Salification, the most commonly employed method for modifying physical-chemical properties, did significantly increase antiviral activity, and different salt forms displayed different antiviral effect. Present study provides fundamental support for development and optimization of phenanthroquinolizidine alkaloids as potential inhibitors of plant virus.This article is protected by copyright. All rights reserved.
    Chemical Biology &amp Drug Design 04/2014; DOI:10.1111/cbdd.12340 · 2.51 Impact Factor
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    ABSTRACT: A collective asymmetric synthesis of phenanthroindolizidine and phenanthroquinolizidine alkaloids (-)-antofine, (-)-cryptopleurine, (-)-tylophorine, and (-)-tylocrebrine was achieved by means of a reaction sequence involving efficient generation of chiral homoallylic amine intermediates by asymmetric allylation of the corresponding tert-butanesulfinyl imine. From these intermediates, the pyrrolidine and piperidine rings were constructed by means of an intramolecular SN2 substitution reaction and a ring-closing metathesis reaction, respectively. The unusual C5-methoxy-substituted phenanthrene moiety of (-)-tylocrebrine was generated by means of an InCl3-catalyzed cycloisomerization reaction of an o-propargylbiaryl compound.
    The Journal of Organic Chemistry 03/2014; 79(8). DOI:10.1021/jo500013e · 4.64 Impact Factor
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    ABSTRACT: Two series of novel 2,4-diphenyl-1,3-oxazolines containing an oxime ether moiety were designed and synthesized via the key intermediate N-(2-chloro-1-(p-tolyl)ethyl)-2,6-difluorobenzamide. The bioassay results showed that the target compounds with an oxime ether substituent at the para position of 4-phenyl exhibited excellent acaricidal activity against Tetranychus cinnabarinus in the laboratory. Moreover, all of the target compounds had much higher activities than etoxazole, as the ovicidal and larvicidal activities of the target compounds I-a-I-l and II-a-II-n against T. cinnabarinus were all over 90% at 0.001 mg L(-1), but etoxazole gave only 30% and 40% respectively at the same concentration. The activity order of compounds with regard to acaricidal activity in vivo was almost consistent with their affinity activity with sulfonylurea receptor (SUR) of Blattella germanica in vitro, hence, it was supposed that the acaricidal mechanism of action of the target compounds was that they can bind with the site of SUR and therefore inhibit chitin synthesis. Moreover, the eminent effect of the compound II-l, [2-(trifluoromethyl)benzaldehyde O-(4-(2-(2,6-difluorophenyl)-4,5-dihydrooxazol-4-yl)benzyl) oxime], against Panonychus citri and T. cinnabarinus in the field indicated that II-l exhibited a promising application prospect as a new candicate for controlling spider mites in the field.
    Journal of Agricultural and Food Chemistry 03/2014; 62(14). DOI:10.1021/jf500461a · 3.11 Impact Factor
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    ABSTRACT: Six known β-carboline, dihydro-β-carboline, and tetrahydro-β-carboline alkaloids and a series of their derivatives were designed, synthesized, and evaluated for their anti-tobacco mosaic virus (TMV) and fungicidal activities for the first time. All of the alkaloids and some of their derivatives (compounds 3, 4, 14, and 19) exhibited higher anti-TMV activity than the commercial antiviral agent Ribavirin both in vitro and in vivo. Especially, the inactivation, curative, and protection activities of alkaloids Harmalan (62.3, 55.1, and 60.3% at 500 μg/mL) and tetrahydroharmane (64.2, 57.2, and 59.5% at 500 μg/mL) in vivo were much higher than those of Ribavirin (37.4, 36.2, and 38.5% at 500 μg/mL). A new derivative, 14, with optimized physicochemical properties, obviously exhibited higher activities in vivo (50.4, 43.9, and 47.9% at 500 μg/mL) than Ribavirin and other derivatives; therefore, 14 can be used as a new lead structure for the development of anti-TMV drugs. Moreover, most of these compounds exhibited good fungicidal activity against 14 kinds of fungi, especially compounds 4, 7, and 11.
    Journal of Agricultural and Food Chemistry 01/2014; 62(5). DOI:10.1021/jf404840x · 3.11 Impact Factor
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    ABSTRACT: 4-(N,N-Dimethylamino)pyridine hydrochloride (DMAP·HCl), a DMAP salt with the simplest structure, was used as a recyclable catalyst for the acylation of inert alcohols and phenols under base-free conditions. The reaction mechanism was investigated in detail for the first time; DMAP·HCl and the acylating reagent directly formed N-acyl-4-(N',N'-dimethylamino)pyridine chloride, which was attacked by the nucleophilic substrate to form a transient intermediate that released the acylation product and regenerated the DMAP·HCl catalyst.
    Organic Letters 12/2013; 16(1). DOI:10.1021/ol4030875 · 6.32 Impact Factor
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    ABSTRACT: Glycoconjugates of phenanthroindolizidine alkaloids targeting tobacco mosaic virus (TMV) RNA were designed, synthesized, and evaluated for their antiviral activity against TMV for the first time. The glycoconjugation of [Formula: see text]-6-O-desmethylantofine (2) and 14-hydroxyltylophorines (3-6) was accomplished in three ways (O-glycosylation manner, using carbamoyloxy as linker arm, and using 1,2,3-triazole as linker arm) with three different sugar units (glucose, galactose, and mannose). The glycoconjugates showed improved water solubility and molecule polarity compared with phenanthroindolizidine alkaloids. The bioassay results showed that C6 was a suitable position for glycoconjugation and O-glycosylation can increase the antiviral activity of phenanthroindolizidine alkaloids indicating that the introduction of sugar units can improve the antiviral activity profile of glycoconjugates. Two O-glycosides of [Formula: see text]-6-O-desmethylantofine, (13aS)-6-O-[Formula: see text]-D-galactopyranosyl-2,3-dimethoxyphenanthro [9,10-b]-11-indolizidinone (10) and (13aS)-6-O-[Formula: see text]-D-mannopyranosyl-2,3-dimethoxyphenanthro [9,10-b]-11-indolizidinone (11) displayed significant higher activity than commercial ningnanmycin, and thus could be considered for novel therapy against plant virus infection.
    Molecular Diversity 10/2013; 18(1). DOI:10.1007/s11030-013-9484-4 · 2.54 Impact Factor