Xanthane sesquiterpenoids: structure, synthesis and biological activity

The aim of this review is to survey the naturally occurring xanthanes and xanthanolides, their structures, biological activities, structure–activity relationships and synthesis. There has been no comprehensive review of this topic previously. On the basis of 126 references, 112 compounds are summarized.     

2-Allyloxy/propargyloxypyridines: synthesis,structure, and biological activity

The alkylation (allylation and propargylation) of 3-cyano-6-dialkylamino-2-pyridones containing a d-annulated ring occurs at the oxygen atom. The structures of the starting compounds and their alkylation products were determined by X-ray diffraction. The neurotropic and antimicrobial activity of alkylation products was examined.     

The solution conformation of glycosyl inositols related to inositolphosphoglycan (IPG) mediators

The preferred solution conformation of the pseudodisaccharides 7–15, containing the structural motifs that have been proposed for the putative inositolphosphoglycan (IPG) mediators of intracellular signalling processes, have been investigated using NMR spectroscopy and molecular mechanics calculations. The results indicate that the different structural motifs (α and β 1–6 or α and β 1–4 glucosaminyl-d-myo-inositol; α and β 1–6 glucosaminyl-d-chiro-inositol) adopt various three-dimensional shapes that may modulate their biological properties.     

Chlorosulfolipids: structure, synthesis, and biological relevance

Chlorosulfolipids have been isolated from freshwater algae and from toxic mussels. They appear to have a structural role in algal membranes and have been implicated in Diarrhetic Shellfish Poisoning. Further fascinating aspects of these compounds include their stereochemically complex polychlorinated structures and the resulting strong conformational biases, and their poorly understood (yet surely compelling) biosynthesis. Discussions of each of these topics and of efforts in structural and stereochemical elucidation and synthesis are the subject of this Highlight.     

Studies of bimetallic carboxylates: their synthesis, characterization, biological activity and X-ray structure

Ten novel diorganotin dicarboxylates containing germanium in the carboxylate ligand have been synthesized and their structures have been characterized by IR, Mössbauer and multinuclear NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopies and X-ray diffraction. Also, the twodiastereotopic protons of the methylene group which are directly attached to the chiral center in these compounds have been successfully analyzed for the first time. The resulted ABX system gives three coupling constants and three chemical shifts. The single crystal X-ray analysis of precursor (p-CH₃C₆H₄)₃GeCH(p-CH₃C₆H₄)CH₂COOH revealed the dimeric structure of the molecule through H-bonding between carboxylic acid groups in a conventional manner. The results of their biological activity suggest that the materials have potential to be used as drugs.     

Thienopyridines: synthesis, properties, and biological activity

The current state and prospects of development of the chemistry of isomeric thienopyridines (synthesis, chemical transformations, and biological activities) are analyzed. Particular attention is given to studies published in the last 10–15 years. Dedicated to Academician V. I. Minkin on the occasion of his 70th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 847–885, April, 2005.     

Thienopyrimidines: synthesis, properties, and biological activity

Data on the methods for the synthesis of isomeric thienopyrimidine derivatives, their chemical transformations, and biological activities are systematized and analyzed. Emphasis is given to studies published over the last 10—15 years.     

Pyranonaphthoquinones--isolation, biological activity and synthesis

A review of the isolation, biological activity and synthesis of pyranonaphthoquinones and closely related compounds is provided.     

Benzofuroxans: their synthesis,properties, and biological activity

The review provides a brief historical background for the establishment of structure of benzofuroxanes. Methods for their synthesis are summarized, and the chemical properties are described, which are splitted into two parts: reactions proceeding with a ring opening of the heterocycle, and those occuring with a participation of the isocyclic moiety. The biological activity of various representatives belonging to the benzofuroxan series is covered in details.

     

Celastraceae sesquiterpenoids: biological activity and synthesis

Plant extracts of the Celastraceae have been used for centuries throughout South America and China as insect repellents and insecticides in traditional agriculture, and also for the treatment of a plethora of medical ailments from stomach complaints and fever to rheumatoid arthritis and cancer. Many of the medicinally interesting properties associated with these crude preparations have now been attributed to a large family of highly oxygenated sesquiterpenoids based on a tricyclic dihydroagarofuran skeleton. In this article, the structural diversity and range of biological activities associated with this intriguing class of natural products are examined with a view to stimulating interest in their total synthesis. Existing synthetic endeavours towards their synthesis are also evaluated.     

Synthesis and biological activity of 1-, 2- or 3-Substituted benzothieno-[2,3-d]triazole derivatives structurally related to trazodone

A series of new 1-, 2- and 3-piperazinylbenzothieno[2,3-d]triazole derivatives structurally related to Trazodone were prepared and tested for their antiserotonergic, antiadrenergic and antihistaminergic in vitro activities together with their analgesic in vivo activity by using Trazodone as the reference compound.     

Two dinuclear Schiff-base complexes: synthesis,characterization, and biological activity

Two complexes, [Zn₂L(µ-OAc)](ClO₄) (1) and [Mn₂L(OAc)₂]?·?4H₂O (2), were synthesized by [2?+?2] cyclo-condensation between 2,6-diformyl-4-fluorophenol and 1,3-propyldiamine in the presence of metal ions M(II) (M?=?Zn and Mn), and were characterized by chemical analyses, IR spectra, electrospray mass spectra, and X-ray determinations. The results show that 1 forms dimers through hydrogen bonding. In 2, lattice waters, forming a 1-D water chain, function as glue to form a 3-D supramolecular network through extended hydrogen bonding. pBR322 plasmid DNA can be transformed to nicked form in air by 1 or nicked and linear forms in air by 2. Moreover, their antibacterial activities against S. aureus were investigated using penicillin as reference system.     

Design and synthesis of certain substituted cycloalkanecarboxamides structurally related to safinamide with anticonvulsant potential

Research on Chemical Intermediates - A series of novel safinamide derivatives were synthesized and biologically evaluated for their anticonvulsant activity against maximal electroshock seizure...     

Chemical synthesis and immunosuppressive activity of dipalmitoyl phosphatidylinositol hexamannoside

Phosphatidylinositol mannosides (PIMs) isolated from mycobacteria have been identified as an important class of phosphoglycolipids with significant immune-modulating properties. We present here the synthesis of dipalmitoyl phosphatidylinositol hexamannoside (PIM(6)) 1 and the first reported functional biology of a synthetic PIM(6). Key steps in the synthetic protocol included the selective glycosylation of an inositol 2,6-diol with a suitably protected mannosyl donor and construction of the glycan core utilizing a [3 + 4] thio-glycosylation strategy. The target 1 was purified by reverse phase chromatography and characterized by standard spectroscopic methods, HPLC, and chemical modification by deacylation to dPIM(6). The (1)H NMR spectrum of synthetic dPIM(6) obtained from 1 matched that of dPIM(6) obtained from nature. PIM(6) (1) exhibited dendritic cell-dependent suppression of CD8(+) T cell expansion in a human mixed lymphocyte reaction consistent with the well established immunosuppressive activity of whole mycobacteria.     

Synthesis,dimerization, and biological activity of hexaoxygenated chalcones related to calythropsin and combretastatins

Five new hexaoxygenated chalcones and one new chalcone photodimer were synthesized and their cytotoxicity against leukemia cell line L-1210 was studied. The three more active compounds were tested for their activity on the inhibition and promotion of tubulin assembly and it was found that these chalcones do not interfere with the tubulin-microtubule system at cytotoxic concentrations, and therefore operate by some different mechanism of action.     

Synthesis of new indole derivatives structurally related to donepezil and their biological evaluation as acetylcholinesterase inhibitors

New series of indole derivatives analogous to donepezil, a well known anti-Alzheimer and acetylcholinesterase inhibitor drug, was synthesized. A full chemical characterization of the new compounds is provided. Biological evaluation of the new compounds as acetylcholinesterase inhibitors was performed. Most of the compounds were found to have potent acetylcholinesterase inhibitor activity compared to donepezil as standard. The compound 1-(2-(4-(2-fluorobenzyl) piperazin-1-yl)acetyl)indoline-2,3-dione (IIId) was found to be the most potent.