Dear readers of the Hacettepe Journal of Biology and Chemistry,

As I begin my sixth year as a Chief Editor of Hacettepe Journal of Biology and Chemistry, it is a great pleasure to greet our readers in this journal once again and to update you on what has happened in five years. 

The Azolla-Anabaena association is important agronomically owing to its capacity to fix atmospheric nitrogen at cheaper and faster rates and making it available to crop plants. Nitrogen fixing capacity of the system is due to the presence of a symbiotic cyanobacterium Anabaena azollae which inhabits the dorsal lobe of the leaves. The system is important as it helps in enrichment and maintaining soil fertility and thus offers sound ecological sustainability on a long term basis. Owing to its several other uses as green manure, water purifier, animal feed etc. The system is referred to as “green gold mine”. However, it is still an underutilized association with tremendous potential for exploitation. 

This paper reports α- and β-glucosidase inhibitory and radical scavenging potential of the metabolites; salazinic acid, sekikaic acid and usnic acid isolated from three terrestrial natural lichen species Ramalina celastri, Ramalina nervulosa and Ramalina pacifica of the genus Ramalinaceae. Lichen metabolites showed both glucosidase inhibitory and radical scavenging capacity. Half-inhibiting concentration (IC50) values of the lichen metabolites; salazinic acid, sekikaic acid and usnic acid are 13.8 to 18.1, 13.8 to 14.6 and 17.7 to 18.9 μg/ mL for the α- and β-glucosidase inhibition. Scavenging of radicals are found with an IC₅₀ values of salazinic acid, sekikaic acid and usnic acid are 17.2 to 20.5, 13.7 to 17.4 and 18.8 to 25.5 μg/mL respectively. Inhibition kinetic studies of the metabolite towards α- and β-glucosidase showed sekikaic acid and salazinic acid have competitive inhibition towards α-glucosidase activity and noncompetitive inhibition for β-glucosidase activity. Usnic acid showed noncompetitive type of inhibition for α-glucosidase and uncompetitive for β-glucosidase activity. 

Aedes albopictus and Aedes japonicus are invasive mosquito species with expanding distributions. Both species are indigenous to the tropical and sub-tropical regions of Southeast Asia; however, they have rapidly established populations in several countries outside their native range over the last few decades. The European continent has not been excluded from these invasions. Aedes albopictus was first reported from Albania in 1979, subsequently from Italy, France, Greece, Switzerland, Belgium, Spain, Netherland sand Germany. Aedesjaponicus was first reported fromFrance in 2000, in Belgium during 2002, and from Germany in 2007. The potential risk for further invasion and/or expansion of either species may be projected based on their biology. Temperate countries in Europe such as Turkey are vulnerable to potential introductions of these invasive species. Existence of a national surveillance program would be a valuable proactive measure for the detection and rapid intervention efforts to prevent establishment of these nuisance mosquito species and the diseases they may transmit. We provide a brief historical background, biology, ecology, larval identification, public health implications, suitable climate areas, and routes of introduction for Ae. albopictus and Ae. japonicus in Turkey. 

Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) [poly(EGDMA-VIM)] microspheres (average diameter=150-200 μm) were prepared by copolymerizing of ethylene glycol dimethacrylate (EGDMA) with n-vinyl imidazole (VIM). Poly(EGDMA-VIM) microspheres were characterized by swelling studies and scanning electron microscope (SEM). The adsorption of Cr(VI) onto the poly(EGDMA-VIM) microspheres was examined in aqueous solutions. The adsorption of Cr(VI) from aqueous solutions was carried at different contact times, Cr(VI) concentrations, and pH. The amount of Cr(VI) adsorbed increased with increasing concentration and decreasing pH. The intraparticle diffusion rate constant was calculated. Adsorption isotherms poly(EGDMA-VIM) have been determined with common isotherm equations such as Langmuir and Freundlich isotherm models. The pseudo first-order kinetic model was used to describe the kinetic data. The Langmuir isotherm model appeared to fit the isotherm data better than the Freundlich isotherm model. Values of the dimensionless separation factor (RL) and the distrubition coefficient (KD) were evaluated. 

The aim of this study is to investigate the preferences of honeybees to collect propolis in Tekirdağ city of Turkey. A total of 92 different propolis samples collected from Tekirdağ were examined under microscope to determine pollen contents and establish the botanical origin of Tekirdağ propolis. 38 different plant families and 51 taxa were identified by pollen analysis of the 92 propolis samples. Among these families Asteraceae family pollen were found most intensive. The most observed pollen in the investigated samples were belong to the taxa of Asteracae, Boraginaceae, Brassicaceae, Fabaceae and Salicaceae families. 

The plant Çöven, Gypsophila simonii is widely distributed throughout Çankırı, where it is a native species, and Turkey. In this study, chemical and physical properties of unripe saponins obtained by extraction from the roots of Gypsophila simonii, an endemic plant, were isolated and investigated. Purified aglycones recovered from acid hydrolysis of the saponins were separated by reversed chromatography on a thin layer of silica gel. The structure was characterized methods of analysis by means of ¹H-NMR, ¹³C-NMR, FTIR and EIMS. The findings indicate that the proposed structure of that saponin was as a new Gypsogenin ester (C₃₁H₅₁O₃) [1,2]. The obtained sapogenin was crystallized for X-ray diffraction; but X-ray analysis results showed that the compound crystallized was only sucrose (C₁₂H₂₂O₁₁). Phytochemical tests showed the presence of terpenoids in the crude extracts. The total saponin content in plant materials and extracts varied to %12.30±0.50. Furthermore in this study, type of ose and total ose (7.0±0.20%), were investigated as qualitative and quantitative. 

The aim of this study was to investigate the effects of BPA that is one of the endocrine disrupting chemicals (EDCs) on the development and reproduction of Drosophila melanogaster. Larvae of D. melanogaster were exposed to 0.1 mg/L, 1 mg/L and 10mg/L BPA. The percentages and times of transition from larvae to pupae and from pupae to adults and the mean offspring number were determined. No differences were found in the transition percentages from larvae to pupae and from pupae to adults (p > 0.05). However, it was found that both the mean pupation and the mean maturation times were delayed with BPA exposures (p < 0.05). In the 0.1 mg/L and 1 mg/L exposed groups, the mean offspring numbers were significantly less than that of the control groups (p < 0.05). 

Anew combination and status, Arabis mollis Steven subsp. graellsiiformis (Hedge) Mutlu comb. & stat. nov., is proposed for Arabis graellsiiformis Hedge, formally known as Turkish endemic. Further morphological and palynological characters of related taxa are discussed. 

In this study, several homobimetallic ruthenium complexes were synthesized by using monometallic ruthenium alkylidene complexes. The ligands in monometallic fractions were modified by phosphine, N-heterocyclic carbene and Schiff Base ligands. The effect of the ligands on formation of homobimetallic complexes and their ROMP (Ring Opening Metathesis Polymerization) activity were investigated. The synthesized complexes and ROMP polymers were characterized by 1H-NMR and FT-IR and the activity results were compared with corresponding monometallic analogs. 

It was found out by carrying out laboratory researches that intensity of cellulose and hemicellulose decomposings by enzyme systems of soil microorganisms is accelerated on combined introducing them with mineral fertilizings and a favorable condition is formed for young-growth humus formation. 

Acomparative study on elemental composition of various eggplant (Solanum melongena L.) samples (n=10) were conducted by using a sensitive method, wavelength dispersive X-ray fluorescence (WDXRF). 28 elements were determined in eggplant samples grown under organic and conventional farming regimes. It was observed that the concentration of Ca, Fe, Mn, P, Mg, Zn, Cl, Na and Cu elements were higher in the eggplant samples grown under organic farming regime. Likewise, Al, Cr, Rb, Br, Si and Sr levels were found in higher levels in the samples grown under conventional farming regime. Our findings clearly revealed that organic eggplants are likely to have higher nutritional mineral content. And the eggplant samples grown under conventional farming regime could contain harmful metals like Al, Cr and Sr that might damage the various systems and/or organs of humans and animals. 

In this study, decomposition process of a dog (Canis lupus familiaris Linnaeus 1758) carcass was examined and 21 species belonging to the families Staphylinidae, Histeridae, Dermestidae, Nitidulidae, Cleridae, Scarabaeidae, Carabidae (Coleoptera), Calliphoridae, Sarcophagidae, Muscidae (Diptera) and Vespidae (Hymenoptera) were collected during two months period at Hacettepe University Beytepe Campus Ankara in 2002. This is the first study in Turkey on forensic entomology and the insect fauna of a dog carcass. 

It is well known that almost all the reactions are catalyzed by enzymes in metabolism of living beings. Environmental conditions leads to very significant changes in living metabolism including fish. These changes may be genetic, hormonal, enzymatic and other physiological defects. The aim of this study was to assess the effects of increasing stock density on the activity of sorbitol dehydrogenase enzyme in liver, muscle, gill and kidney tissues of rainbow trout. Fish were reared at different stock densities (15 kg/m³, 20 kg/m³, 25 kg/m³ and 30 kg/m³), and after adaptation period of 30 days, the experiment was carried out for two months. Stock density of the control group was 15 kg/m³. Increasing stock density caused significant inhibition of sorbitol dehydrogenase enzyme. Overall results indicate that increasing stock density significantly blocks the SDH activity in rainbow trout tissues and that this might cause undesirable results by disrupting physiological balance as inhibition of this enzyme leads to sorbitol accumulation. 

The use of magnetic crosslinked chitosan beads for the removal of hazardous dye “Brilliant Blue FCF” from aqueous solution at different initial pH levels, contact times and initial concentrations was studied. The equilibrium adsorption data were described by Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherms. The experimental results showed that the maximum adsorption of dye pH was 2.0. Equilibrium was attained in 150 min. The equilibrium sorption was best described by the Dubinin-Radushkevich adsorption isotherm model. The estimated values of E for the present study were found to be >8kj/mol at room temperature which implies that adsorption of Brilliant Blue FCF onto magnetic crosslinked chitosan beads is chemisorption. The study indicates that dye adsorption onto chitosan beads is becoming an alternative replacement for the conventional adsorbents used for dye removal purposes. Also, as they are magnetic it is easy to separate the beads from the water after the treatment.