A series of 2-(1H-indol-3-yl)ethylthiourea derivatives were prepared by condensation of 2-(1H-indol-3-yl)ethanamine with appropriate aryl/alkylisothiocyanates in anhydrous media. The structures of the newly synthesized compounds were confirmed by spectroscopic analysis and the molecular structures of 8 and 28 were confirmed by X-ray crystallography. All obtained compounds were tested for antimicrobial activity against Gram-positive cocci, Gram-negative rods and for antifungal activity. Microbiological evaluation was carried out over 20 standard strains and 30 hospital strains. Compound 6 showed significant inhibition against Gram-positive cocci and had inhibitory effect on the S. aureus topoisomerase IV decatenation activity and S. aureus DNA gyrase supercoiling activity. Compounds were tested for cytotoxicity and antiviral activity against a large panel of DNA and RNA viruses, including HIV-1 and other several important human pathogens. Interestingly, derivative 8 showed potent activity against HIV-1 wild type and variants bearing clinically relevant mutations. Newly synthesized tryptamine derivatives showed also a wide spectrum activity, proving to be active against positive- and negative-sense RNA viruses.

Thirty six novel heterocyclic derivatives of ethyl 2-(2-pyridylacetate) were efficiently synthesized. The new compounds involve the linkage of a 2-pyridyl ring with thiosemicarbazide (compounds 1–7), 1,2,4-triazole (compounds 1a–7a), 1,3,4-thiadiazole (compounds 1b–7b), and 1,3,4-oxadiazole (compounds 1f–7f) moieties. The last group of compounds 1e–7e involves the connection of a 2-pyridyl ring with 1,2,4-triazole and thiourea. ¹H-NMR, ¹³C-NMR and MS methods were used to confirm the structures of the obtained derivatives. The molecular structures of 3, 3b, 7a and 7f were further confirmed by X-ray crystallography. All obtained compounds were tested in vitro against a number of microorganisms, including Gram-positive cocci, Gram-negative rods and Candida albicans. In addition, the obtained compounds were tested for cytotoxicity and antiviral activity against HIV-1.

2,3-Dichloronaphthalene (2,3-DCN) and 2,3-dibromonaphthalene (2,3-DBN) were synthesized, purified and used to grow single crystals in the form of thin plates. X-ray crystallographic studies, performed for the first time, showed that molecules in both isostructural crystals are arranged in the herringbone pattern. These crystals, lightly doped with terrylene (Tr), appeared to be very good systems for optical single-molecule studies. Fluorescence excitation spectra of single Tr molecules at 5 K in excess of the dominating purely electronic (0, 0) and intense vibronic line of ∼250 cm⁻¹ frequency had a new, “184 cm⁻¹” line, absent in the spectrum of isolated (D_2h) Tr. Quantum-chemistry calculations indicated that this new line was the fingerprint of the deformation of the Tr molecule in the crystal structure, which lowered its symmetry to C_2h.