Synthetic routes to lipidic diamines and amino alcohols: a class of potential antiinflammatory agents

Anthelmintic activity of aminoalcohol and diamine derivatives against the gastrointestinal nematode Teladorsagia circumcincta

Gastrointestinal nematodes (GIN) infections are a serious problem in livestock production due to the great economic losses they cause. Their control is increasingly difficult because of the rapid development of drug resistance and the limited number of available drugs. Therefore, this study evaluated 18 aminoalcohol and 16 diamine derivatives against eggs, first and third stage larvae from a susceptible and a resistant isolate of Teladorsagia circumcincta collected from sheep. The effectiveness of the in vitro anthelmintic activity of the compounds was evaluated using three different procedures: Egg Hatch Test (EHT), Larval Mortality Test (LMT) and Larval Migration Inhibition Test (LMIT). Those compounds with activities higher than 90 % in the initial screening at 50 μM were selected to determine their half maximal effective concentration (EC₅₀). In parallel, cytotoxicity assays were conducted on Caco2 and HepG2 cell lines to calculate Selectivity Indexes (SI) for each compound. The diamine 30 presented the best results in preventing egg hatching, displaying the lowest EC₅₀ value (1.01 ± 0.04 μM) of all compounds tested and the highest SI (21.21 vs. Caco-2 cells). For the LMIT, the diamine 34 showed the highest efficacy, with EC₅₀ values of 2.67 ± 0.08 and 3.02 ± 0.09 μM on the susceptible and resistant isolate of the parasite, respectively.

Four new long-chain aliphatics from the feces of Trogopterus xanthipes

Chemical investigation of Trogopterus feces has led to the isolation of four new long-chain aliphatics, including two new fatty alcohols, 8,15-nonacosanediol (1) and 6,13-nonacosanediol (2), one new fatty acid ester, dihexyl 7,7'-oxydiheptanoate (3), and one new ceramide, (2R)-2-hydroxy-N-[(2S,3S,4R,11E)-1,3,4-trihydroxydocos-11-en-2-yl]heneicosanamide (4). Their structures were elucidated by means of chemical and extensive spectroscopic analysis. Compound 3 exhibited moderate activity of antithrombin in vitro.

Phase transitions in crystals of racemic long chain 2-amino alcohols

Various techniques, namely differential scanning calorimetry, optical microscopy, dielectric and Raman spectroscopy, all covering a wide range of temperatures, were used to study the thermodynamically stable phases and molecular mobility of crystals of long chain 2-amino alcohols. The results showed that two different crystal forms are present in each sample. The temperature behaviour of the phases is studied in details.

Amino Acid Based Synthesis of Chiral Long Chain Diamines and Tetramines

A method for the synthesis of long chain diamines and tetramines starting from natural α-amino acids is reported. Diamines and tetramines were prepared through the Wittig olefination reaction of N-protected amino aldehydes obtained from phenylalanine and lysine. A 1,2,17,18-tetramine was synthesized using (2S)-1-azido-2-[bis(tert-butoxycarbonyl)-amino]-5-oxopentane as key-intermediate compound.

An Efficient Preparation of 1,2-Diamino-1-phenylheptane

A convenient four-step method for the preparation of the lipophilic vicinal diamine 1,2-diamino-1-phenylheptane is described. Condensation involving octan-2-one, benzaldehyde and ammonia is reported. Regioselective Schmidt rearrangement of 2,6-diphenyl-3-pentyl-piperidin-4-one (1) to 2,7-diphenyl-3-pentyl hexahydrodiazapin-5-one (3) is presented. Hydrolysis of 2,7-diphenyl-3-pentyl hexahydrodiazapin-5-one to 1,2-diamino-1-phenylheptane (4) is also reported for the first time.

Synthesis of enantiopure omega-functionalized C15 alpha-amino carboxylates

An efficient route for the synthesis of enantiopure omega-hydroxy, omega-carboxy, omega-oxo, and omega-amino alpha-amino acids and bis-alpha-amino acids was developed. The synthesis of omega-trityloxy delta,epsilon-unsaturated alpha-amino acids was based on the Wittig reaction of methyl (2S)-2-[bis(tert-butoxycarbonyl)amino]-5-oxopentanoate with omega-trityloxy alkylidene triphenylphosphoranes. After hydrogenation, the omega-hydroxy alpha-amino acid was used as starting material for the synthesis of other omega-functionalized alpha-amino acids. The length of the side chain of alpha-amino acids or bis-alpha-amino acids depends on the starting alkanediol or dibromide used to prepare the phosphoranes.

Synthesis of (S)-alpha-amino oleic acid

An efficient synthesis of (S)-alpha-amino oleic acid was developed. The fully protected FA derivative was obtained in four steps starting from methyl (2S)-2-[bis(tert-butoxycarbonyl)amino]-5-oxopentanoate. These steps are (i) olefination of the starting aldehyde with the appropriate phosphonate anion, (ii) hydrogenation of the double bonds, (iii) controlled reduction of omega-ethyl ester to an aldehyde in the presence of alpha-methyl ester, and (iv) a Wittig reaction of the latter aldehyde with the suitable ylide. Free alpha-amino oleic acid was prepared after deprotection of the amino group followed by saponification in a total yield of 24%. N-tert-Butoxycarbonyl-protected amino oleic acid and the corresponding amino alcohol were prepared in high yield. The structures of the products have been established by various spectroscopic techniques.