Dear readers of the Hacettepe Journal of Biology and Chemistry,

We are pleased to introduce you the fourth issue of Hacettepe Journal of Biology and Chemistry. This volume is composed of 12 papers which present some of the leading techniques of biology and chemistry authored by a distinguished group of scientists. 

In the present study, combinatorial effects of various flavonoids were evaluated against two Gram-positive and two Gram-negative bacteria of clinical relevance. The results indicated the antibacterial potential of each flavonoid under mild-to-moderate concentrations; however, their effectiveness increased when both flavonoids were used in combination with various degree of concentrations. It has also been observed that Gram- positive bacteria were found more susceptible than that of Gram-negative bacteria; the reasons can be attributed towards their cell wall structure. Flavonoids and their optimal combinations could be used as suitable alternatives towards finding new antimicrobial for the treatment of infectious diseases. 

Turkish coal is generally poor quality and the levels of chemical and radiological toxic trace elements in it are higher with respect to mean values of activity concentrations given in United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) Report. The main pathways through which the population living around soal-fired power plant (CFPP) is exposed to natural radionuclides are external and internal (ingestion and inhalation) dose and fly ash particles are the major component of the risk. It is estimated that the people working or living near the CFPP in Turkey receive a dose in between 0.1 mSv to 1 mSv extra from CFPP because nearly all the region of Turkey uranium (U) and thorium (Th) content in the coal are higher than 5 ppm to 7 ppm and around 25 ppm to 40 ppm respectively. Continuous monitoring is essential to determine occupational exposure levels in all stages of the coal fuel-cycle and proper measures should be taken to prevent direct contact of the ash pile with the top soil and local drainage systems. 

Helichrysum species (Asteracea) are widely found in Anatolia. Helichrysum species has used ethnomedicine for centuries. We report here the total phenolic contents and antioxidant activities of the methanolic extracts of Helichrysum plicatum DC. subsp. plicatum species, together with their HPLC analysis results of individual some phenolic acids and flavonoids. 17 different phenolic constituents were measured by reverse phase- high performance liquid chromatograpy (RP-HPLC) in the three parts of the plant. Total phenolic compound and ferric reducing antioxidant power (FRAP) were used as antioxidant capacity determinants. All parts of the plants showed high antioxidant activity containing large amounts of antioxidant compounds. Chlorogenic acid, quercetin and rutin found in the three parts of the samples as main phenolic components and absisic, ferulic, epicathecin and cinnamic acids have minor concentration or haven’t been detected at all. The methanolic extracts of the plants proved to be a good source of phenolic compounds and antioxidants agents that might serve to protect health and fight against several diseases.

There is a great need for developing of eco-friendly antifouling biocides since negative ecological effects have been proven for current antifouling biocides. In the present study acute toxicities of potassium sorbate (KS), tannic acid (TA), copper(II) sulphatepentahydrate (CS), Caulerpa prolifera extract (CPE) were investigated on the survival of A.salina. LC50 values were found for KS, TA, CS and CPE as 19.96 g/L, 155.30 g/L, 10.47 g/L and 20.40%, respectively. In order to investigate the antifouling performances, the biocides were immobilized into phytagel and submerged into sea for one month in inner bay of İzmir. In conclusion, slightly dissolving versions of studied eco- friendly biocides could be replaced with copper based antifouling biocides. 

Endoplasmic reticulum (ER) stress is involved in many diseases including diabetes, cancer and aging. Tauroursodeoxycholic acid (TUDCA) is a chemical chaperone that reduces ER stress. Caenorhabditis elegans (C. elegans), a widely used model organism in aging studies, also suffers from ER stress. In this study, we tested the effect of TUDCA on C. elegans life span with the aim to decipher the contribution of ER stress on C. elegans aging. We tested TUDCA at the concentrations of 0.625, 1.25, 2.5, 3.75, 5, 7.5, 10, 15 and 20 mM. It showed a negative effect on the life span at all of the tested concentrations except 3.75 mM. At this concentration it had no toxicity nor an effect on longevity. One of the previously reported critical micellar concentrations (CMC) of TUDCA is closer to this concentration. Therefore TUDCA’s mechanism of action could be explained, at least in part, by its micelle formation. It could have exerted negative effects at both lower and higher concentrations than CMC. If it had a positive effect on life span through ameliorating ER stress at the CMC, this could have been neutralized by its partial toxicity. Our results can be helpful in future studies on TUDCA which is a very important and promising therapeutical agent. 

Teucrium L. is one of the well-known genus for botanists and it belongs to Section Scordium Boiss. of Lamiaceae which is represented by a single species, T. scordium L. in Turkey. An interesting Teucrium specimen has been collected from south-east Turkey, Şırnak. The specimen was identified as Teucrium melissoides Boiss. & Hausskn. ex Boiss. The species is a new record for the Flora of Turkey and it is closely allied to T. scordium L. The type specimen of the taxon has been examined at G herbarium alongside other specimens of the taxon and photographed. The descriptions of the species given in both Boissier and Rechinger have been revised and it is enlarged by giving the measurements of various characters here. A photograph of the type specimen and the Turkish material taken from field has been supplied with a map. 

Akdağ Natural National Park, settled on Sandıklı county in Afyon province and Çivril county in Denizli province, is a transition area between Central Anatolian and Aegian regions. Akdağ is approximately 2000 m in elevation and bears both forest and steppe characteristics. There is no previous work encountered related to the insect fauna of the study field. In the observations for the determination of insect fauna in Akdağ Natural National Park, 152 species that belong to 45 families have been determined. 

The genus Nigella L. has approximately 22 species worldwide, distributed mostly in the Mediterranean region and closely adjacent areas. Various taxonomic treatments of the genus have been carried out as accounts in various floristic studies.

In the course of an ongoing taxonomic study on the genus Nigella, an extensive field trip has been carried out in Syria. During the study at Aleppo area near the Turkish border, the specimens of Nigella nigellastrum, which is the first report for the flora of Syria, have been collected. In consideration of the relevant literature, the species number of the genus has been raised to ten with this new record. A picture of the species taken from field has been given. 

Effects of dietary conditions on many life history traits have been studied for a long time with Drosophila. However, many laboratories use different diets and techniques, which make it difficult to compare the results obtained from various studies. For this reason an optimization protocol for dietary restriction (DR) studies seems to be necessary and in fact recently an optimization protocol published by Bass et al. [1]. In our study we compared the standard diet (S) that we use in our laboratory and the proposed diet (P) with the restricted groups of both diets. In our work, differences between two different dietary protocols with respect to egg-to-adult viability and developmental time were investigated. The P diet did not show any significant differences between the groups with respect to developmental time. On the contrary, the S diet showed significant differences in the yeast and yeast + sugar restricted groups when compared with the respective control and sugar restricted groups. 

Pleurocercoids of the tapeworm Ligula intestinalis (Linnaeus, 1758) were recorded from three fish species [Squalius cephalus (Linnaeus, 1758), Alburnus escherichii Steindachner, 1897 and Gobio gobio (Linnaeus, 1758)] in Çamkoru Pond (Sakarya Basin-Turkey). This is the first record of L. intestinalis from G. gobio in Turkey. Infection prevelance is lower for S. cephalus (7.07%) and G. gobio (7.5%) when compared to A. escherichii (25.71%). The age composition of infected individuals of A. escherichii, G. gobio and S. cephalus, populations was as follows: III-VII; IV-V and I-II. The parasitisation index varied in A. escherichii between 0 and 18%, in G. gobio between 0 and 11.07% and in S. cephalus between 0 and 3.57%. The aim of this study is to compare dynamics of L. intestinalis pleurocercoids in three fish species of Çamkoru Pond. For this purpose; prevelance and intensity of infection, age and sex compositions of infected populations, seasonality of infection, the length and weight range of host species have been obtained and compared with other studies. 

Reeds emerge in shallow coastal areas where water and land meet. Because of this feature they are at transition and buffer point between two ecosystems. Not only they contain creatures belonging to these two environments but also they help shaping the interaction between the environments in a balanced manner.

A reed which has not been ruined functions just as a technical treatment system. Firstly, the plants in the water cut the speed of the water and makes the particles’ in it sink thus providing physical treatment. At eh second stage, the creatures living in reeds decompose the organic substances and realize biological treatment step. At the last stage, plants and other creatures living in reeds takes the substances they need into their bodies thus providing chemical treatment. After passing these stages, the water infiltrates through the dunes and joins the system in a clear manner. Today, cleaning waters by establishing artificial reed pools in the areas, where no natural reeds have grown, has become a commonly used method.

The aim of this study is to put forward the relation between the mowing manner of reed plants which were cut generally for economical reasons in wetlands and the natural filtration by means of Bendimahi example. Images taken from the mentioned area and other satellite images that have been taken from the area during the study, which has taken one year, have been blended with literature knowledge and interpreted.

The idea of mowing a certain amount of reeds every year which has been recommended by the experts may be useful for shallow and still waters without a large amount of water input-output and which do not flow into a water system thereafter. However, this idea does not provide an efficient solution for streams flowing down fast from highlands such as Bendimahi Stream. Instead of this, it will be more appropriate to cut the reeds as wide bands to clean the water and in a way to cut down the speed of the water and provide a dam before it. This model may be applied by cutting different bands every year. The desired continuous filtration will be provided with this system which we can call as “bands model”. Implementation of such a model will contribute to the protection of both biodiversity and clean state of Van Lake. 

It is necessary to characterize genetic diversity of the plant resources for their effective usage and protection. There are various well known marker systems to analyze and define the plant genomes. Randomly Amplified Polymorphic DNA (RAPD) is one of the efficiently used techniques for distinguishing the genetic variation among the wheat species as well as the other plants.

The objective of this study is to characterize the genetic diversity of 11 wild emmer (T. dicoccoides) and 8 emmer (T. dicoccon) populations each of which is found in Turkey. For this purpose wheat samples were analyzed with 25 RAPD markers of which 20 were found to be informative. Of the total 178 amplification products, 85 were polymorphic. An average percentage of polymorphism was detected as 47.75%. Dendrograms were constructed using an unweighted pair-group method with arithmetical averages (UPGMA). The UPGMA analysis revealed that the lowest similarity was between emmer wheat recorded as TUR 02456 and wild emmer wheat recorded as TUR 03399, whereas, the genetic distance between two emmer wheat which are recorded as TUR 03562 and TUR 03564 was the highest. Consequently, RAPD could clearly assessed the genetic diversity at inter and intraspecific levels and these species can be considered as valuable gene resources for future breeding and conservation programs.