Synthesis and Biological Activity of Philanthotoxin Analogs

Sodium ion channels, acetylcholine esterase and neurotransmitter receptors in insect neurons and skeletal muscles are often made as target by practical neurotoxic pesticides. But insects can create resistance after using a pesticide for a long time. So th…     

Synthesis and Biological Evaluation of Analogs of Methyl Ursolate 3-O-β-Chacotrioside as H5N1 Viral Entry Inhibitors

The earliest stage of influenza virus infection is the viral entry to the host cell. In our previous work, we discovered the first three small molecule H5N1 viral entry inhibitors 1–3. Here, based on saponin 3, methyl ursolate 3-O-β-chacotrioside, several analogs were synthesized and evaluated to understand the structure-activity relationships of this type of compound on the H5N1 viral entry inhibitory activity. The preliminary studies demonstrated that unlike saponins 1 and 2, it is possible to reduce the 3-O-chacotriosyl residue of compound 3 to a disaccharide without affecting the viral entry activities significantly. The results obtained will render new clues to the understanding of the antiviral profile for these types of compounds.     

Semisynthesis and Biological Evaluation of Taxayuntin 13－［N－Benzoyl－（2’R，3’S）－3’－phenylisoserinate］

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Synthesis and Bio-activities of Pyrazolyl or Pyridinyl Substituted Tonghaosu Analogs

11 pyrazolyl or pyridinyl substituted tonghaosu analogs were synthesized. Structures of all the new compounds were confirmed by ^1H NMR, IR, MS, HREIMS or elemental analysis. Their antifeedant activity against larvae of large white butterfly （Pieris brassicae L.）, larvicidal activity toward mosquito （Culex quinquefasciatus Say） and growth control activity toward larvae of Spodoptera litura Fab were examined. Some of them exhibited antifeeding activities comparable to or stronger than tonghaosu Z-1. Based on the activity data, the preliminary structure-activity relationship was also discussed, which might be instructive for finding out lead compounds with better bioactivities in the future.     

Synthesis and Biological Activities of Substituted Triazolethione Schiff Base

Six novel Schiff bases have been synthesized by the condensation reaction of 4-amino-5-（4-pyridyl）-2,4-dihydro-1,2,4-triazole-3-thione with various benzaldehydes. The sfructures of the compounds have been confirmed by ^1H NMR, IR and elemental analysis. The preliminary bioassay indicated that the title compounds possessed good fungicidal activities to several vegetable pathogens.     

Synthesis and Biological Activity of Tonghaosu Analogs Containing Phenoxy-phenyl Moiety

A new series of phenoxy-phenyl moieties containing tonghaosu analogs with varied B-ring 9 were synthesized and characterized by spectral studies. Their insect antifeedant activity against Pieris brassicae and insecticidal activity against Culex quinquefasciatus were investigated. Compound 9e exhibited excellent antifeeding activity.     

Synthesis and Biological Evaluation of Pyranone Analogues of Territrem B

As a highly selective and potent acetylcholinesterase(AChE)inhibitor,territrem B wasisolated by Ling et al.from a strain of Aspergillus terreus in19791,2.Zhao et alreported mimic preparation of territrem B analogues from triterpenoids and found thatthe enone moiety and aromatic ring played important roles in their syntheticcompounds3,4.To further detect essential pharmacophors for AChE inhibitors,wesimplified the A/B ring system of territrem B and synthesized a number of pyranonepharmacop…     

Syntheses and Characterization of Metal Complexes of L－Lysine－N，N，N＇，N＇－tetraacetic Acid and L－Lysine－N，N，N＇，N＇－tetramethylenepho sphonic Acid

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Synthesis and Biological Evaluation of N,N′-di(thiopheneacetyl)diamines Series as Antitubercular Agents

The series of new N,N′-di(thiopheneacetyl)diamines derivatives, 8–17, were synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis(TB), and the activity expressed as the minimum inhibitory concentration (MIC) in μ g/mL. Compound 13 was the only one determined to be active and exhibited a MIC 50 μg/mL, indicating that the alkyl chain-length of the diamines is critical for biological activity. This class of compound has not been evaluated before, and it could be a good starting point to find new lead compounds in the fight against multi-drug resistant TB.     

Synthesis of Substituted 3H-Indole-modified b-Cyclodextrin

The hydrophobic cavities of cyclodextrins and the inclusion with various organic molecules in the aqueous solution make them useful in chemical and biological activities1, one of which is the modified cyclodextrins acting as indicators of molecular recognition. Cyclodextrins, which are spectroscopically inert, can be converted into spectroscopically active compounds by modifing one or two of the hydroxy groups with appropriate chromophores, and used as molecular sensor due to the capability of…     

Synthesis of N‐Glycoside Analogs via Thionolactones

Indolyl N‐glycoside analogs were obtained by a two‐step sequence via indole N‐thioamides. Treatment of thionobutyrolactone with indolylmagnesium bromide provides the corresponding indole N‐thioamide. The use of 10:1 toluene:THF as solvent is important in favoring N‐ over C3‐acylation. Treatment of the ω‐hydroxythioamide with 2 equiv of Meerwein's reagent followed by sodium borohydride gives the corresponding N‐(tetrahydrofuranyl)indole. Addition of carbon nucleophiles gives access to ketose nucleoside analogs, while activation of the ω‐hydroxyl group can give access to tetrahydrothiophene N‐glycosides.     

Synthesis and Biological Activities of N—Phosphory Branched Peptides

A series of N-phosphoryl branched peptides were synthesized by coupling of various N-phosphoryl amino acids to L-Lysine methyl ester,and their structures were confirmed by ^31PNMR,^1H NMR,MS and elemental analysis.The results of cell biological tests indicated that compound 1d and 1e obviously inhibites the growth of both k562 and A2780 cells.     

Synthesis and Biological Evaluation of Novel Isonucleosides with 1,2,4‐Triazole‐3‐Carboxamide

Novel 1,2,4‐triazole isonucleosides (1 and 2) were efficiently synthesized starting from D‐ribose and D‐xylose, respectively. The key steps were condensation of cyclic sulfate 8 with methyl‐1,2,4‐triazole‐3‐carboxylate and nucleophilic displacement of the tosylate 15 with methyl‐1,2,4‐triazole‐3‐carboxylate, respectively.     

Chemoenzymatic Synthesis and Biological Evaluation of (−)‐Conduramine C‐4

Abstract

Previously unreported (?)‐conduramine C‐4 was synthesized in six steps from a bacterial bromobenzene metabolite in 23% overall yield. The chemoenzymatic route involved toluene dioxygenase dihydroxylation, β‐epoxidation, epoxide ring‐opening, Staudinger reduction, radical debromination, and Amberlite‐ catalyzed hydrolysis. (?)‐Conduramine C‐4 and other related compounds synthesised were assayed for galactosidase‐activity inhibition against β‐D‐galactoside galactohidrolase isolated from Aspergillus oryzae.     

First Synthesis of N‐Substituted Amino and N‐Sulfonylaminated Methylthiopyrimidines: Reaction of Dimethyl N‐Cyanodithioiminocarbonate With Substituted Hydrazides

A novel and efficient method for the synthesis of a new variety of methylsulfanylpyrimidines by the reaction of dimethyl N‐cyanodithioiminocarbonate with substituted hydrazides. The synthetic potential of the method is demonstrated.     

Efficient and Simple Synthesis of Substituted 3‐Phenyl‐7‐methoxybenzopyrans as Pseudo‐Vitamin‐D3 Analogs

An efficient and simple synthesis of substituted 3‐phenyl‐7‐methoxybenzopyrans as pseudo‐vitamin‐D₃ analogs in good yields under mild reaction conditions is described.     

Synthesis of Substituted 3H-Indole-modified β-Cyclodextrin

Substituted 3H-indole modified β-cyclodextrin (β-CD) was prepared by the reaction of 6-deoxy-6-[(2-aminoethyl)amino]-β-CD (CDen) with 2-[(p-amino)phenyl]-3, 3-dimethyl-5-car-boxyl-3H-indole (substituted 3H-indole) in the presence of dicyclohexylcarbodiimide (DCC) and 1-hydroxybenzotriazole (HOBt). The product has been characterized by means of elementalanalysis, MS and ^1H NMR.     

Synthesis of Two New Types of N-Phenyl and N,N'-Diphenyl Azathiacrown Ether Analogs

Inrecentyears,peoplehavepaidmoreattentionto1lliacrownelffersbecause1llesecomPOundshavecomplexabilitiesforsomepositionmetalions."'Althoughiltiacrownetherscanformcomplexeswitilsometrallsitionmetalions,theydemonstratelowselectivityforsomeindividualmetalions.SuchselectivityisgovernedbytoPOlogicalconsidefatioll,cavitysizes,andthenatllfeofhledonoratoms.Thevariationofaledonor-atomhasbeenemployedtOchangetilesanitiesofligandstowardsomeindividualmetalionsinordertoenhancetheselectivityforUlesemetalions…