Ergosterol derivatives exhibited copious promising biological activities. The fungus Gyromitra esculenta is widely distributed in Europe and North America. In order to examine the chemical properties of Gyromitra esculenta, a phytochemical study has been preceded and resulted in the isolation of the steroid, ergosta-5, 22-dien-3β-ol (brassicasterol), from its methanol extract. The complete identification and absolute configuration of the isolated compound have been established by X-ray structural analysis to be (22E, 24R)-24-methylcholesta-5, 22-dien-3beta-ol. The reported cytotoxicity and the great structural similarity of the isolated compound with the cocrystallized ligand of the aromatase enzyme inspired us to run molecular docking studies against that protein. Ergosta-5, 22-dien-3β-ol occupied the target protein with a binding mode almost the same as the cocrystallized ligand and a binding affinity of −33.55 kcal/mol, which was better than that of the cocrystallized ligand (−22.61 kcal/mol). This promising result encouraged us to conduct in silico ADMET and toxicity studies of ergosta-5, 22-dien-3β-ol against 6 models, and the results expected the likeness of the isolated compound to be a drug. In conclusion, ergosta-5, 22-dien-3β-ol has been isolated from Gyromitra esculenta, identified by X-ray structural analysis, and exhibited promising in silico activities against aromatase enzyme.

Thiazolo[3,2-a]pyrimidines were obtained in good yield by the reaction of 4-aryl-substituted 3,4-dihydropyrimidine(1H)-2-thiones and methyl chloroacetate in boiling toluene. Their structures were shown by 1 H NMR spectroscopy and X-ray crystallography.Recently there has been a considerable growth in the number of publications on the chemistry of 4-aryl-3,4-dihydropyrimidin-2-ones and 4-aryl-3,4-dihydropyrimidine-2-thiones obtained by three-component condensation in the Biginelli reaction is associated with the displaying by these readily available compounds a wide range of pharmacological activities -analgesic, antibacterial, antihypertensive, etc. [1-3]. The attention of synthetic chemists was drawn to the presence in 4-aryl-3,4-dihydropyrimidine-2-thiones of several reactive nucleophilic centers allowing for a variety of mono-and dialkylation, acylation [4][5][6], and also the very prospective cyclization reaction. For example, the conversion of 4-phenyl-3,4-dihydropyrimidine(1H)-2-thione into 3,5-dihydro-2H-thiazolo[3,2-a]pyrimidine by boiling it in DMF with chloroacetic acid has been described [7]. Attempts to carry out analogous cyclizations with 4-methoxy-and 2,4-dimethoxyphenyl-substituted 3,4-dihydropyrimidine(1H)-2-thiones gave rise to considerable amounts brightly colored by-products, difficult to separate from the desired product.

A series of new N-acylsubstituted thioureas, the compositions and structures of which were determined by IR and PMR spectroscopy and mass spectrometry, were synthesized from the alkaloid anabasine. The crystal structure of one of the products, N-(anabasino-1-thiocarbonyl)furan-2-carboxamide, was confirmed by x-ray structure analysis. It was also shown that this compound exhibited moderate antibacterial activity.Anabasine was discovered in 1929 by Orekhov A. P. from Anabasis aphilla and acts as a respiratory and cardiac stimulant. It is used in practical medicine as anabasine hydrochloride as an anti-smoking agent [1,2]. It was also broadly used previously as an insecticide for pests of such industrial cultures as cotton, fruit trees, and vegetables and gourds [3,4].Introducing a sulfur atom into physiologically active compounds not only decreases their overall toxicity due to the facile oxidizability of its derivatives in vivo but also produces other types of bioactivity. Also, it is known that most thiourea derivatives possess valuable pharmacological properties and are used as antituberculosis, antitumor, antimicrobial, anti-ulcer, and other therapeutic agents [5][6][7].We have previously synthesized thiourea derivatives of the alkaloids cytisine, 1-ephedrine, and d-pseudoephedrine with unsaturated and aromatic acyl derivatives.In continuation of that work we synthesized acyl-substituted thiourea derivatives based on anabasine by a convenient preparative isothiocyanate method. Isothiocyanates are very reactive compounds and react with amines under rather mild conditions.The starting isothiocyanates were synthesized by a convenient preparative in situ method (without isolation) by heating the corresponding acid chlorides (benzoylchloride, p-methylbenzoylchloride, p-bromobenzoylchloride, 2-furancarboxylic acid chloride) with KSCN in acetone. Further reaction of the resulting isothiocyanate lutions with anabasine under mild conditions formed 1-4.The products were white (or slightly yellowish) crystalline compounds that were soluble in polar organic solvents.

Keywords: methacryloylthiosemicarbazide of isonicotinic acid, intramolecular heterocyclization, X-ray crystallography.Previously the synthesis was reported of β-N-(methacryloylcarbamothioyl)isonicotinohydrazide (1) which, on boiling in 2-propanol for 10-16 h, underwent intramolecular cyclization to give β-N-(5-methyl-4-oxo-5,6-dihydro-4H-1,3-thiazin-2-yl)isonicotinohydrazide (2) [1]. The objective of the present work includes the study of the reaction of thiosemicarbazide 1 with a series of amines with the aim of obtaining the corresponding products of nucleophilic addition at the activated C=C bond.However mixing compound 1 with equimolar quantities of cyclic secondary amines (morpholine, piperidine) or alkaloids (anabasine, cytosine) in ethanol or 2-propanol solutions at about 30°C gave not the expected addition products 3 but the product of heterocyclization of compound 1 -the substituted 5,6-dihydro-1,3-thiazin-4-one 2 in 82% yield. Under these conditions cyclization of compound 1 occurred considerably faster (~1 h) than the same reaction in boiling 2-propanol reported previously [1]. The yield of product 2 did not depend on either the structure or the basicity of the amine and alkaloid starting materials.It is probable that the presence of base in the reaction medium facilitates the formation of the thiol form of compound 1 which is necessary for its cyclization. The 1 H NMR and IR spectra of samples of compound 2 obtained by using various amines or on boiling in 2-propanol [1] were identical.

Optimal conditions were found for the synthesis of a number of new N-aminoglycosides of the alkaloid cytisine, using commercially available monosaccharides, namely, D-glucose, D-galactose, D-xylose, and L-arabinose. X-ray structural analysis indicated an absolute -anomeric configuration of N-(-D-galactopyranosyl)cytisine in the crystalline state. The comparative cytotoxicity of cytisine and some of its N-aminoglycosides was determined.