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Hidroksamske kiseline su slabe organske kiseline koje se rabe u farmaceutskoj industriji, prehrambenoj industriji i metalurgiji. Poznati su kelatori iona metala te se koriste u njihovoj ekstrakciji iz okoline, a u novije vrijeme rabe se u liječenju brojnih bolesti. Cilj ovoga rada bio je sintetizirati novi derivat hidroksamske kiseline i odrediti njegovu molekulsku i kristalnu strukturu. Rendgenskom strukturnom analizom na jediničnom kristalu utvrđeno je da derivat hidroksamske kiseline, N,N',N''-tribenziloksidikarbonimidni diamid kristalizira u triklinskom sustavu te da su u asimetričnoj jedinici pronađene dvije simetrijski neovisne molekule slične konformacije. Duljine veza i valentni kutevi u skladu su s već opaženima za slične spojeve. Karakteristično za priređeni spoj jest da njegove molekule posjeduju unutarmolekulsku vodikovu vezu koja „zaključava“ konformaciju središnjeg dijela molekule, tj. čini ga planarnim. U kristalnoj strukturi, molekule su povezane u centrosimetrične dimere koji su vodikovim i slabijim interakcijama povezani u lance. Hydroxamic acids are weak organic acids that are used in the pharmaceutical or food industries and metallurgy. They are known as good metal ion chelators which is particulary useful in extraction from the environment or in the treatment of many diseases. The aim of this study was to synthesize a new hydroxamic acid derivative and to determine its molecular and crystal structure. X-ray structural analysis on a single crystal revealed that the hydroxamic acid derivative, namely, N, N',N''- tribenzyloxydicarbonimide diamide crystallizes in the triclinic system with two symmetrically independent molecules (of similar conformation) in the asymmetric unit. The bond lengths and valence angles are comparable to those found in the literature. Characteristic of the prepared compound is that its molecules have an intramolecular hydrogen bond that "locks" the conformation of the central part of the molecule, i.e., makes it planar. In the crystal structure, the molecules are linked into centrosymmetric dimers that are linked into chains by hydrogen and weak interactions.

Novija istraživanja pokazuju da su epigenetske modifikacije jednako bitne u procesu razvoja tumora kao i mutacije gena. Posebno se ističu acetilacije, odnosno deacetilacije jer utječu na strukturu kromatina čime određuju gensku ekspresiju. U tumorskih stanica uočena je prekomjerna aktivnost histonskih deacetilaza (HDAC) koje uklanjaju ε-acetilnu skupinu iz bočnih aminokiselinskih ogranaka lizina. Dolazi do utišavanja tumorsupresorskih gena te aktivacije gena koji potiču preživljavanje i proliferaciju stanica tumora. Lijekovi inhibitori HDAC kompleksiraju ione cinka iz aktivnog mjesta enzima. Prema kemijskoj strukturi dijelimo ih u četiri skupine, od kojih su najzanimljivije hidroksamske kiseline zbog visoke sposobnosti keliranja iona metala i inhibicije HDAC-a. Cilj ovoga diplomskog rada bila je sinteza hibridnog derivata primakina i cimetne kiseline s terminalnom hidroksamskom kiselinom, za kojeg se pretpostavlja da bi, zbog svojih strukturnih karakteristika, mogao imati antimalarijsko i/ili citostatsko djelovanje. Isprobane su tri sintetske metode, no unatoč tome, sinteza ciljne molekule nije bila uspješna. Recent research shows that carcinogenesis cannot be explained only by genetic alterations, but also involves epigenetic modifications. In particular acetylation and deacetylation affect the structure of chromatin which determines gene expression. In tumor cells excessive activity of histone deacetylases (HDAC), enzymes that remove the ε-acetyl group from the lateral lysine amino acid residues, was observed. It results in suppression of tumor-suppressor genes and activation of genes that stimulate survival and proliferation of tumor cells. HDAC inhibitors complex zinc ions found in the enzyme's active site. According to the chemical structure, they are divided into four groups, of which hydroxamic acids are the most interesting ones, due to their high metal ion chelating ability. The goal of this diploma thesis was the synthesis of a hybrid derivative primaquine and cinnamic acid with terminal hydroxamic acid moiety, which might, due to the structural characteristics, exert cytostatic and/or antimalarial activity. Although three synthetic methods were employed, synthesis of the target compound was not achieved.

Sintetizirana je serija novih strukturnih analoga 3,5-disupstituiranih hidantoina 5a-h s lipofilnim supstituentima na C-5, N-3 ili na oba atoma intramolekulskom ciklizacijom amida N-(1-benzotriazolkarbonil)aminokiselina 4a-h. Sintetizirani su derivati NSAID 6–12: reducirani derivati ketoprofena 6a,b, NSAID benzotriazolidi 7a-h, NSAID hidroksamske kiseline i njihovi derivati 8a-y, derivati ketoprofena 9a-i, 10a-f, 11a-f i 3-hidroksipropilamidi NSAID 12a-e. Reducirani derivati ketoprofena 6 pripravljeni su katalitičkim hidrogeniranjem ketoprofena uz Pd/C ili Pd/C(en). NSAID s karboksilnom funkcionalnom (ibuprofen, fenoprofen, diklofenak, indometacin, ketoprofen, 6a,b) u reakciji s kloridom 1-benzotriazol-karboksilne kiseline (1) dali su odgovarajuće NSAID benzotriazolide 7, koji su bili polazni spojevi u sintezi derivata NSAID 8–12. Razvijena je nova sintetska metoda za pripravu NSAID hidroksamskih kiselina i derivata 8, reakcijom NSAID benzotriazolida 7 i odgovarajućih hidroksilamina (hidroksilamin, N-metilhidroksilamin, O-metilhidroksilamin, O-etilhidroksilamin i O-benzilhidroksilamin) ili katalitičkim hidrogeniranjem O-benzilnih derivata NSAID hidroksamskih kiselina. Derivati ketoprofena 9, 10 i 3-hidroksipropilamidi NSAID 12 sintetizirani su iz NSAID benzotriazolida 7 i odgovarajućih amina, dok su derivati ketoprofena 11 sintetizirani katalitičkim hidrogeniranjem amida ketoprofena 10 uz Pd/C(en). Provedena su sljedeća biološka ispitivanja: antitumorsko, antimikrobno, antivirusno i antioksidacijsko djelovanje, inhibicija ureaze, lipooksigenaze i lipidne peroksidacije. Najbolje antitumorsko djelovanje pokazao je 8c, najbolje antimikrobno 8b,d, najbolje antivirusno 5a i 8y, a najbolje antioksidacijsko djelovanje 8o. Najjači inhibitor ureaze bio je 8f, a lipooksigenaze 11f. Najbolji inhibitor lipidne peroksidacije bio je 9e. 3,5-Disubstituted hydantoin derivatives 5a-h with lipophilic substituents at C-5, N-3 or both atoms were prepared by the intramolecular cyclization of the corresponding N-(1-benzotriazolecarbonyl)amino acid amides 4a-h. The following NSAID derivatives 6–12 were prepared: the reduced ketoprofen derivatives 6a,b, NSAID benzotriazolides 7a-h, NSAID hydroxamic acids and their derivatives 8a-y, ketoprofen derivatives 9a-i, 10a-f, 11a-f and NSAID 3-hydroxypropylamides 12a-e. The reduced ketoprofen derivatives 6 were prepared by the catalytic hydrogenation of ketoprofen with Pd/C or Pd/C(en) catalyst. NSAIDs bearing carboxylic group (ibuprofen, fenoprofen, diclofenac, indomethacin, ketoprofen, 6a,b) reacted with 1-benzotriazole carboxylic acid chloride (1) affording benzotriazolides 7, which were the starting compounds in the synthesis of NSAID derivatives 8–12. A new synthetic method for the synthesis of NSAID hydroxamic acids and their derivatives was developed. They were obtained in the reaction of NSAID benzotriazolides 7 with an appropriate hydroxylamine (hydroxylamine, N-methylhydroxylamine, O-methylhydroxylamine, O-ethylhydroxylamine or O-benzylhydroxylamine) or by the catalytic hydrogenation of O-benzyl derivatives of NSAID hydroxamic acids. Ketoprofen derivatives 9, 10 and NSAID 3-hydroxypropylamides 12 were prepared from NSAID benzotriazolides 7, in the reaction with an appropriate amine, while compounds of the series 11 were obtained by the catalytic hydrogenation of ketoprofen amides 10 with Pd/C(en). The compounds were evaluated for their biological activity: antitumor, antimicrobial, antiviral and antioxidant activity, inhibition of urease, lipoxygenase and linoleic acid lipid peroxidation. The best antitumor activity was exerted by 8c, antimicrobial by 8b,d, antiviral by 5a and 8y, and antioxidant by 8o. The strongest inhibitor of urease was 8f, while 11f was the strongest inhibitor of lipoxygenase. Compoung 9e showed the highest inhibition of linoleic acid lipid peroxidation.

Antibacterial and antifungal activity of N-phthaloylamino acid hydroxamates 1-3 /C6H4(CO)2N-x-CONHOH, x = amino acid residues of glycine, ß-alanine and D-phenylglycine/ was examined against 44 strains of Gram-positive and Gram-negative bacteria, and 10 species of yeasts. The level of antimicrobial effects was established using the in vitro agar assay and the standard broth dilution susceptibility test. N-phthaloyl-D-phenylglycine-hydroxamic acid (3), the substance with the highest lipophilicity (log P), showed the best antibacterial activity, especially against Gram-negative bacteria. Minimum inhibitory concentration of 3 was 0.008 mg mL-1 in the activity against Yersinia enterocolitica O3, confirmed by a large inhibition zone (30 mm) by the diffusion test. Hydroxamates inhibit growth by chelation of PDF enzyme metal in both Gram-positive and Gram-negative bacteria, and LpxC enzyme in Gram-negative enzyme. Phthalimides apear to contribute to inhibition by destabilizing m-RNA. Antifungal activity of substances 1-3 is not very expressed., Ispitano je djelovanje N-ftaloil-aminokiselinskih hidroksamata 1–3 opće formule C6H4(CO)2N-X-CONHOH (X = aminokiselinski ostatak glicina, -alanina ili D-fenilglicina) na 44 soja Gram-pozitivnih i Gram-negativnih bakterija i 10 vrsta kvasaca. Antibakterijski i antifungalni učinak testiran je postupkom difuzije na hranjivom agaru i standardnom metodom dilucije. Najbolja inhibicija rasta, osobito izražena prema Gram-negativnim bakterijama, utvrđena je za N-ftaloil-D-fenilglicin hidroksamsku kiselinu (3) s najvećom lipofilnošću. Za soj Yersinia enterocolitica O3 minimalna inhibitorna koncentracija (0,008 mg mL–1) potvrđena je inhibicijskom zonom od 30 mm pomoću difuzijskog testa. Hidroksamati inhibiraju rast keliranjem metala PDF enzima kod Gram-pozitivnih i Gram-negativnih bakterija, te LpxC enzima kod Gram-negativnih bakterija. Ftalimido struktura pridonosi inhibiciji, pretpostavlja se, destabilizacijom m-RNA. Antifungalna aktivnost spojeva 1–3 nije osobito izražena.