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In this paper, a review of reactions with benzotriazole as synthetic auxiliary is given. In contrast to most other azoles, benzotriazole reacts with phosgene in molar ratio 1:1 yielding carboxylic acid chloride (BtcCl, 1), which readily reacts with nucleophiles giving reactive compounds. These products can be easily transformed into carbamates, ureas, semicarbazides, carbazides, sulfonylureas, sulfonylcarbazides, nitroalkanic acid esters, etc. In addition, benzotriazole was used in the synthesis of various heterocyclic compounds: benzoxazine, kinazoline, triazinetrione, hydantoin and oxadiazine derivatives. The reaction of chloride 1 with amino acids enabled the use of benzotriazole in peptide chemistry, with triple role of benzotriazolecarbonyl group as N-protecting, N-activating, and both N-protecting/C-activating group. N-(1-benzotriazolecarbonyl)-amino acids 25 are starting compounds in the synthesis of various amino acid, di- and tripeptide derivatives, hydantoic acids and hydroxyureas.Benzotriazole was also applied in the preparation of polymer-drug and thiomer-drug conjugates, polymeric prodrugs with drugs covalently bound to the polymeric carriers. Such macromolecular prodrugs may offer many advantages compared to other drug delivery systems such as increased drug solubility, prolonged drug release, increased stability. It is also possible to accumulate the drug at the site of the pathological process and to minimize its toxicity. In this paper, the binding of drugs from various therapeutic groups (mostly nonsteroidal, anti-inflammatory drugs) to polymersof polyaspartamide type by the benzotriazolide method is described.

Polyketides and non-ribosomal peptides represent a large class of structurally diverse natural products much studied over recent years because the enzymes that synthesise them, the modular polyketide synthases (PKSs) and the non-ribosomal peptide synthetases (NRPSs), share striking architectural similarities that can be exploited to generate "un-natural" natural products. PKS and NRPS proteins are multifunctional, composed of a co-linear arrangement of discrete protein domains representing each enzymic activity needed for chain elongation using either carboxylic acid or amino acid building blocks. Each domain is housed within larger modules which form the complex. Polyketide and peptide antibiotics, antifungals, antivirals, cytostatics, immunosuppressants, antihypertensives, antidiabetics, antimalarials and anticholesterolemics are in clinical use. Of commercial importance are also polyketide and peptide antiparasitics, coccidiostatics,animal growth promoters and natural insecticides.Polyketides are assembled through serial condensations of activated coenzyme-A thioester monomers derived from simple organic acids such as acetate, propionate and butyrate. The choice of organic acid allows the introduction of different chiral centres into the polyketide backbone. The active sites required for condensation include an acyltransferase (AT), an acyl carrier protein (ACP) and a ß-ketoacylsynthase (KS). Each condensation results in a ß-keto group that undergoes all, some or none of a series of processing steps. Active sites that perform these reactions are contained within the following domains; ketoreductase (KR), dehydratase (DH) and an enoylreductase (ER). The absence of any ß-keto processing results in the incorporation of a ketone group into the growing polyketide chain, a KR alone gives rise to a hydroxyl moiety, a KR and DH produce an alkene, while the combination of KR, DH and ER domains lead to complete reduction to an alkane. Most often, the last module contains the thioesterase domain (TE) responsible for the release of linear polyketide chain from the enzyme and final cyclisation. After assembly, the polyketide backbone typically undergoes post-PKS modifications such as hydroxylation(s), methylation(s) and glycosylation(s) to give the final active compound.Non-ribosomal peptides are assembled by the so-called "multiple carrier thio-template mechanism". Three domains are necessary for an elongation module: an adenylation (A) domain that selects the substrate amino acid, analogous to a polyketide AT domain, and activates it as an amino acyl adenylate; a peptidyl carrier protein (PCP) that binds the co-factor 4-phosphopantetheine to which the activated amino acid is covalently attached, analogous to the ACP of a PKS; and a condensation (C) domain that catalyzes peptide bond formation, again analogous to the KS in modular PKSs. The NRPSs also contain a (Te) domain located at the C-terminal of the protein which is essential for release of linear, cyclic or branched cyclic peptides. Auxiliary activities can further enlarge the structural diversity of the peptide especially common are epimerization domains (Epim) that convert the thioester-bound amino acid from an L- to D- configuration.There has been a lot of interest in the last few years in generating new compounds for the production of novel drugs by manipulating the programming of such clusters in vitro (e.g. the idea of combinatorial biosynthesis). However, an important barrier to the progress is the fact that most changes made by in vitro methods result in very low yields or no detectable product. A possible solution to the yield problem would be the generation of novel clusters by homologous recombination in vivo, because this would favour more closely related sequences and should reduce problems caused by non-functional incompatible junctions.The Unified Modeling Language (UML) was used to define the platform independent integral generic program packages, CompGen and ClustScan, which are under development to model these processes in silico. The heart of CompGen is a specially structured database, based on BioSQL v1.29, which connects the biosynthetic order of synthase/synthetase enzymes to the sequences of the component polypeptides. The additional linkage to the gene sequences allows the integration of DNA sequence with product structure. The database contains sequences of the well-characterised PKS/NRPS clusters, and non-annotated sequenced clusters whose structure and functionis yet unknown, to act as building blocks for the production of novel products. It is easy to add custom sequences to the database and to annotate them by the use of propriety protein profiles designed by Pfam database and HMMER. One function of the program is the ability to generate virtual recombinants between clusters. This can be done using a recombination model (with optional parameters) to predict sites for homologous recombination or by user defined recombination sites (e.g. to model in vitro genetic manipulation such as module replacement). The program predicts the linear polyketide structure of the resulting "un-natural" natural products with a chemical description using isomeric SMILES. Molecular modelling of the subsequent spontaneous cyclisation process produces structures for a virtual compound database for further molecular modelling studies using PASS and CDD technology. An optional "reverse genetics" module analyses a given chemical structure to see if it could be produced by a novel PKS/NRPS synthesis cluster and suggests the DNA sequence of a suitable cluster based on building blocks derived from clusters contained in the database.Overall, the CompGen allows in silico generation of the database of novel "un-natural" natural chemical compounds that can be used for in silico screening using PASS or CDD technology. The other integral generic program package, ClustScan, will recognise and annotate new gene clusters from microbial genome sequencing projects or in metagenomes of soil and/or marine microorganisms.

The development of Croatian chemistry from the end of the Second World War to the establishment of the Republic of Croatia is outlined. Briefly discussed is the founding and development of the Chemistry Department of the Faculty of Natural Sciences and Mathematics, and the Rugjer Bošković Institute. Also presented is the postwar structure and organization of the chemical-technological study at the Technical Faculty and later at the Faculty of Technology. The chemical lectures and research in chemistry at the Faculty of Nutrition and Biotechnology, Faculty of Pharmacy and Biochemistry, Faculty of Medicine, Faculty of Veterinary Medicine, Facultyof Agronomy and Faculty of Forestry are reviewed. This article follows logically our first article in this series entitled Croatian Chemistry in the 20th Century. I. From the Turn of the Century to May 8,th 1945 (Kem. Ind. 56 (2007) 403–416).

In high pressure processing, foods are subjected to pressures generally in the range of 100 – 800 (1200) MPa. The processing temperature during pressure treatments can be adjusted from below 0 °C to above 100 °C, with exposure times ranging from a few seconds to 20 minutes and even longer, depending on process conditions. The effects of high pressure are system volume reduction and acceleration of reactions that lead to volume reduction. The main areas of interest regarding high-pressure processing of food include: inactivation of microorganisms, modification of biopolymers, quality retention (especially in terms of flavour and colour), and changes in product functionality. Food components responsible for the nutritive value and sensory properties of food remain unaffected by high pressure. Based on the theoretical background of high-pressure processing and taking into account its advantages and limitations, this paper aims to show its possible application in food processing. The paper gives an outline of the special equipment used in highpressure processing. Typical high pressure equipment in which pressure can be generated either by direct or indirect compression are presented together with three major types of high pressure food processing: the conventional (batch) system, semicontinuous and continuous systems. In addition to looking at this technology’s ability to inactivate microorganisms at room temperature, which makes it the ultimate alternative to thermal treatments, this paper also explores its application in dairy, meat, fruit and vegetable processing. Here presented are the effects of high-pressure treatment in milk and dairy processing on the inactivation of microorganisms and the modification of milk protein, which has a major impact on rennet coagulation and curd formation properties of treated milk. The possible application of this treatment in controlling cheese manufacture, ripening and safety is discussed. The opportunities for its application within the meat processing sector are also discussed, particularly the specific effects of high pressure on the colour, texture, nutritive value and functional properties of fresh and processed meat. This paper also considers the possibilities of implementing high-pressure technology in fruit and vegetable processing with the aim to maintain microbiological safety, nutritive value, “fresh-like” appearance and antimutagenic properties. The intention of this paper is to broaden the knowledge of experts and technologists regarding implementation possibilities of high pressure, as one of the emerging technologies in the various food-processing sectors. Given the trend of growing consumer preferences for fresh-like, additive-free and microbiologically safe food, high pressure processing is likely to find its future application in food processing for niche products with added value. Obrada visokim tlakom podrazumijeva podvrgavanje tekuće ili čvrste hrane, s ambalažom ili bez nje, djelovanju tlaka od 100 do 800 MPa (1200 MPa). Temperatura obrade može se kretati od ispod 0 °C do iznad 100 °C, a vrijeme izloženosti djelovanju tlaka, ovisno o cilju obrade, može varirati od nekoliko sekundi do preko 20 minuta. Zbog djelovanja visokog tlaka dolazi do smanjenja obujma sustava i pospješivanja onih reakcija koje vode smanjenju obujma. Potencijal primjene visokog tlaka u obradi hrane je u inaktivaciji mikroorganizama, modifikaciji funkcionalnih svojstava biopolimera, postizanju funkcionalnosti proizvoda te zadržavanju čimbenika kvalitete (boja, aroma, nutritivni sastav). Komponente odgovorne za specifičnu nutritivnu vrijednost i organoleptičke značajke hrane praktički su neosjetljive na djelovanje tlaka. Cilj rada je, polazeći od teorijskih principa djelovanja visokog tlaka, uzimajući u obzir njegove prednosti i nedostatke, prikazati mogućnosti primjene u postupcima obrade hrane. U radu su također opisani tipovi uređaja za tretiranje visokim tlakom koji se mogu primijeniti u obradi hrane. Osim sposobnosti uništavanja mikroorganizama pri sobnoj temperaturi što ovu tehnologiju čini danas jedinom komercijalno primjenjivom alternativom termičkom tretiranju, u radu su prikazane i specifične mogućnosti primjene visokog tlaka u preradi mlijeka, mesa te voća i povrća. S obzirom na trend rastuće potražnje za hranom bez dodataka koja u velikoj mjeri ima zadržane značajke kvalitete (boja, aroma, nutritivni sastav, tekstura), uz ujedno zajamčenu mikrobiološku stabilnost, može se očekivati da će metoda obrade hrane visokim tlakom u budućnosti naći svoju širu primjenu i to upravo za proizvode koji zahvaljujući svojoj dodanoj vrijednosti imaju istaknuto mjesto na tržištu.

This article is the second part of a series dealing with organometallic and bioorganometallic chemistry. In the first part of this series a short review on the history and development of these disciplines was given, emphasizing the importance and scope of bioorganometallic chemistry as a new field dealing with conjugates of organometallics and biomolecules (DNA, PNA, amino acids, peptides...). From the variety of biorganometallics, syntheses and properties of simple conjugates of ferrocene with natural amino acids/peptides were elaborated inter alia. This material is the basis for the second part in which ferrocene amino acids are described. The introduction presents nonproteinogenic alicyclic and aromatic amino acids as the models for the title compounds. Naturally occurring amino acids labelled with ferrocene moiety mostly retain properties of the biomolecules included. Contrary to these ω-ferrocenylamino acids, one could imagine specific amino acids with inserted ferrocene core belonging to either homo- or heterodisubstituted type. The central part of this article is devoted to our investigations of the second type - H2N-(CH2)m-Fn-(CH2)n-COOH. The general rational procedure for synthesis of these compounds and of their N- and/or C-protected derivatives via the azide intermediates N3-CO-(CH2)m- Fn-(CH2)n-COOMe has been described. In the solid state derivatives of ferrocene amino acids contain intermolecular hydrogen bonds giving dimeric structures, three-dimensional networks or endless helical chains. The solutions of homologues Ac-NH-(CH2)m-Fn-(CH2)n-COOMe in nonpolar solvents are dominated by open form conformers. Compounds containing 2–3 ferrocene cores connected by amide, imide and oxalamide spacers were prepared by oligomerization of 1'-aminoferrocene-1-carboxylic acid (Fca) or by its condensation with the appropriate reagents. Similar to natural amino acids, ferrocene amino acids are water-soluble substances with high melting points, insoluble in organic solvents.

This paper deals with a bibliometric analysis of journal Kemija u industriji for the period 2000–2009. The results of the analysis show that the journal is still dealing with the problem of publishing scientific papers, which was also detected in a previous similar analysis (M. Jokia et al. (2002)). Furthermore, in 82.1 % of categorized papers at least one author is from Croatia, while in 88.4 % at least one author is from neighboring countries (Croatia and other ex-Yugoslavia countries). This data reveals the strong national and regional orientation of the journal, which can be related with the language of publishing (mostly Croatian – 76.4 %), as well as with one of the basic functions of the journal according to its mission, which is to develop and improve chemistry and engineering terminology and nomenclature in the Croatian language. Journal citation analysis is based on the citation data gathered from the bibliographic and citation databases Scopus and Web of Science (WoS). Still, according to the specific bibliometric journal indicators(Impact Factor (IF), SCImago Journal Rank (SJR) and Source Normalized Impact per Paper (SNIP)), the analysis shows that Kemija u industriji could find its place among other related world journals.

Due to the demand for higher production capacity and natural-gas energy savings, improvements were made to the rotary dryers in the drying process of wet pelletized oil-furnace carbon blacks. Since the rotary dryers were originally designed for drying semi-wet pelletized oil-furnace carbon blacks, they did not entirely satisfy optimal conditions for drying wet pelletized oil-furnace carbon blacks. Figure 1 shows the drying principle with key dimensions. The energy for drying the wet pelletized oil-furnace carbon blacks was provided by natural gas combustion in an open-furnace system with an uncontrolled feed of combustion air. Improvements on the rotary dryers were carried out by adjusting the excess oxygen in the gases passing through the butterfly valve on the dryer exhaust stack. By regulating the butterfly valve on the dryer exhaust stack, and applying the prescribed operations for drying wet pelletized oil furnace carbon blacks, the excess oxygen in the tail gases was adjusted in the range of φ = 3.0 % and 5.0 %, depending on the type of oil-furnace carbon blacks. Suggested also is installation of a direct-reverse automatic butterfly valve on the dryer exhaust stack to automatically determine the volume fraction of oxygen in the tail gas, and the volume flow rate of natural gas for combustion. The results the improvements carried out are shown in Tables 3 to 5. Table 2 shows the thermal calculations for the hood of the rotary dryer. Preheating of the process water in the temperature range of 70 °C and 80 °C is also recommended using the net heat from the oil-furnace process for wet pelletization. The results of preheating the process water are shown in Table 1. Depending on the type of oil-furnace carbon black, the aforementioned improvements resulted in natural gas energy savings ranging from 25 % to 35 % in relation to the average natural gas requirement in the drying process, and thus a reduction in carbon emissions of up to 40 %, which is shown in Table 6. A schematic of the next proposed situation for complete automatization of the process for drying wet pelletized oil-furnace carbonblacks is shown in Figure 2.

The influence of portland cement class on the corrosion rate of steel reinforcement in cement mortar caused by penetrating chloride or sulfate from the environment in already hardened cement mortar is investigated in this paper. Three classes of portland cement have been used for the tests, PC 35, PC 45 and PC 55. Cylindrical samples of cement mortar with steel reinfor- cement in the middle were treated 6 months at room temperature in the following solutions: w(SO42-) = 2.1 % and w(Cl-) = 5 %. Two techniques have been used for testing corrosion rate of steel reinforcement in cement mortar: Tafel extrapolation technique and potentiodynamic polarization technique. Investigations were conducted by potentiostat/galvanostat Princeton Applied Research 263A-2 with the software PowerCORR®. The results of both techniques indi-cate the most active corrosion of steel reinforcement in the samples prepared from cement PC 35 in both treated solutions, while the lowest corrosion of the steel reinforcement was observed in cement samples prepared from cement PC 55. This conclusion was drawn by analyzing the results shown in Figs. 1–4. Comparing corrosion current density of samples, working electrodes, Figs. 1 and 2, Table 2, the results show the most stable corrosion of steel reinforcement in samples prepared from cement PC 55, and the most active corrosion in samples prepared from ce- ment PC 35. The most active corrosion in samples prepared from cement PC 35 is evident from the positions of the open circuit potentials whose values are less for samples prepared from cement PC 35 in both the treated solution, Figs. 1 and 2, Table 2. Comparison of the anodic polarization curves of the working electrodes in both the treated solutions, Figs. 3 and 4, also shows that the intensity of corrosion is the largest for the working electrodes prepared from cement PC 35 and the smallest for the working electrodes prepared from cement PC 55. Investigation results should be considered as preliminary. To make the recommendations for the construction of reinforced concrete structures in the maritime environment the impact of sulphates on concrete and steel bars should be investigated. U ovom je radu ispitivan utjecaj klase portland-cementa na brzinu korozije čelične armature u cementnom mortu, uzrokovane prodiranjem klorida ili sulfata iz okoliša u već očvrsli cementni mort. Za ispitivanja su upotrijebljene tri klase portland-cementa, PC 35, PC 45 i PC 55. Radi navedenih ispitivanja cilindrični uzorci od cementnog morta s čeličnom armaturom u sredini tretirani su šest mjeseci na sobnoj temperaturi u sljedećim otopinama: w(SO42-) = 2,1 % i w(Cl-) = 5 %. Za ispitivanje brzine korozije čelične armature u cementnom mortu primijenjene su elektrokemijske tehnike potenciostatske polarizacije, i to tehnika ekstrapolacije Tafelovih krivulja i tehnika potenciodinamičke polarizacije. Ispitivanje je provedeno na potenciostatu/ galvanostatu Princeton Applied Research 263A-2, programskim paketom PowerCORR®. Rezultati obje primijenjene tehnike pokazuju da su korozijski najaktivnije čelične armature u uzorcima pripremanim od cementa klase PC 35 u obje tretirane otopine, dok su korozijski najstabilnije čelične armature u uzorcima pripremanim od cementa klase PC 55. Rezultate provedenih istra?ivanja treba smatrati preliminarnima. Radi davanja preporuka za gradnju armiranobetonskih konstrukcija u morskom okolišu, potrebno je provesti ispitivanja utjecaja sulfata na beton i armaturu, na betonskim i armiranobetonskim uzorcima.