Synthesis and Anticancer Activity of Functionalized Thieno[2,3-d]pyrimidine Compounds and Their Triazinyl and Tetrazinyl Derivatives

Russian Journal of Bioorganic Chemistry - New thienopyrimidine derivatives substituted with amino and hydrazinyl side chains were synthesized starting with 2-hydrazinyl substituted thienopyrimidine...     

Discriminant analysis as a tool to identify catfish (Ariidae) species of the excavated archaeological otoliths

Catfish otoliths excavated from two archaeological sites in Kuwait, Sabiyah (ca. 7000 Years Before Present) and Al-Khidr, ca. 4000 YBP, were compared with those of Kuwait’s modern catfish. Otoliths from Kuwait’s four species of catfish, Netuma bilineata, N. thalassina, Plicofollis dussumieri, and P. tenuispinis were collected after recording total length and weight. Data recorded for both ancient and modern otoliths, including annual ring (age), weight, length and four otolith radii from transverse sections, were subject to discriminant analysis to differentiate among species and develop classification functions for otoliths. Comparisons of the results from the ancient and modern otoliths showed that most of the excavated otoliths (78% from Sabiyah and 100% from Al-Khidr) belong to the two presently dominate species N. bilineata and P. tenuispinis, indicating that ichthyofauna of Kuwait Bay may not have changed much in the past 7000 years.     

Incidence of Echinococcus granulosus in Domestic Dogs in Palestine as Revealed by Copro-PCR

Hydatidosis or echinococcosisis considered a neglected zoonotic disease despite its high burden in the livestock industry and the high risk of infection by humans in endemic areas. In a cross-sectional study we estimated the copro-Incidence and also genotyped Echinococcus granulosus isolates from domestic dogs using polymerase chain reaction (PCR). Medical archives in nine major hospitals in Palestine were reviewed to determine incidence of E. granulosus infection detected in humans during surgery. Faecal samples were collected from 93 domestic dogs in three districts with the highest number of human cases: Al-Khalil (Hebron), Tubas and Jenin. Genomic DNA was extracted from dog faecal samples and amplified by PCR targeting the repeat DNA sequence (EgG1 Hae III) followed by sequencing of five positive samples. Genotyping was determined by sequencing and BLAST searching of mitochondrial cytochrome c oxidase subunit (CO1). The incidence of E. granulosus infection detected in humans at surgery was 1.2 per 100,000 in the West Bank and 1.0 per 100,000 in Gaza Strip. Seventeen of 93 domestic dogs (18%) were positive, based upon comparison with the Echinococcus DNA control. The five sequenced samples were confirmed to be E. granulosus. Successfully genotyped sample belonged to E.granulosus sensu stricto (formerly G1-G3 complex, sheep strain). For domestic dogs, age group (13-24 months) and sex were identified as two risk factors for contracting E. granulosus. The study identified the high incidence of E. granulosus sensu stricto in dogs in Palestine.     

Cytogenetic,cytotoxic and GC–MS studies on concrete and absolute oils from Taif rose,Saudi Arabia

Taif rose (Rosa damascena trigintipetala Dieck) is a sort of damask rose, which is considered as one of the most important economic products of Taif. In this study, the authors investigated the possible cytotoxic, genotoxic, antimutagenic and anticancer effect of concrete and absolute rose oils. The results showed that both concrete and absolute rose oils were cytotoxically and genotoxically safe at a dose of 10 μg/ml when tested on cultures of normal human blood lymphocytes. Also, the results showed significant antimutagenic activity at p < 0.001 for absolute rose oil at the same dose level when tested on cultures of normal human blood lymphocytes supplemented with 300 ng/ml mitomycin C (MMC). On the other hand, concrete and absolute oils exerted a cytotoxic activity against two kinds of human cancer cell lines: HepG2 and MCF7. Concrete oil showed cytotoxic activity against HepG2 and MCF7 with a half maximal inhibitory concentration (IC₅₀) of 16.28 and 18.09 μg/ml, respectively, whereas absolute rose oil showed its cytotoxic activity against HepG2 and MCF7 with an IC₅₀ of 24.94 and 19.69, respectively. From this study, it is concluded that concrete and absolute rose oils are cytotoxically and genotoxically safe at a dose of 10 μg/ml when tested on cultures of normal human blood lymphocytes. In addition, absolute oil has an antimutagenic activity at the same dose. Further investigations are needed to study the activity of higher doses of both oils in vitro and in vivo in experimental animals in order to evaluate the capability of using these oils as therapeutic for treatment of some kinds of cancers.     

Antimicrobial activities ofStreptomyces pulcher,S. canescens andS. citreofluorescens against fungal and bacterial pathogens of tomatoin vitro

Thirty-seven actinomycete species isolated from fertile cultivated soils in Egypt were screened for the production of antimicrobial compounds against a variety of test organisms. Most of the isolates exhibited antimicrobial activities against Gram-positive, Gram-negative, and acid-fast bacteria, yeasts and filamentous fungi, with special attention to fungal and bacterial pathogens of tomato. On starch-nitrate agar, 14 strains were active againstFusarium oxysporum f.sp.lycopersici (the cause ofFusarium wilt), 18 againstVerticillium albo-atrum (the cause ofVerticillium wilt), and 18 againstAlternaria solani (the cause of early blight). In liquid media, 14 isolates antagonizedPseudomonas solanacearum (the cause of bacterial wilt) and 20 antagonizedClavibacter michiganensis ssp.michiganensis (the cause of bacterial canker). The most active antagonists of the pathogenic microorganisms studied were found to beStreptomyces pulcher, S. canescens (syn.S. albidoflavus) andS. citreofluorescens (syn.S. anulatus). The antagonistic activities ofS. pulcher andS. citreofluorescens against pathogenic bacteria in liquid media under shaking conditions. The optimum culture conditions were determined.     

Practice with confidence: Analyzing confidence level of final year dental students from four Saudi dental colleges in Riyadh

ObjectiveTo investigate the confidence level of final year dental students in Riyadh.MaterialsCross-sectional study was conducted at four dental colleges in Riyadh (N = 312, 220 and 70,5% responded). Oneway ANOVA and post hoc Tukey-Kramer was used.ResultsThe greatest self-reported confidence scores were for pit fissure sealent (4.6(0.7)). Whereas, students reported least confidence in conducting surgical extractions (2.7 (1.2)). Females were found more confident in conducting preventive resin restorations, oral hygiene instructions, and rubber dam placement as compared to male who were more confident in surgical extraction, copy dentures, veneer preparation and managing orthodontic emergencies.ConclusionAll students were confident in performing essential dental procedures however higher confidence was observed in performing simple procedures compared to more complex ones.     

Woody cover in African savannas: the role of resources, fire and herbivory

Aim To determine the functional relationships between, and the relative importance of, different driver variables (mean annual precipitation, soil properties, fire and herbivory) in regulating woody plant cover across broad environmental gradients in African savannas. Location Savanna grasslands of East, West and Southern Africa. Methods The dependence of woody cover on mean annual precipitation (MAP), soil properties (texture, nitrogen mineralization potential and total phosphorus), fire regimes, and herbivory (grazer, browser + mixed feeder, and elephant biomass) was determined for 161 savanna sites across Africa using stochastic gradient boosting, a refinement of the regression tree analysis technique. Results All variables were significant predictors of woody cover, collectively explaining 71% of the variance in our data set. However, their relative importance as regulators of woody cover varied. MAP was the most important predictor, followed by fire return periods, soil characteristics and herbivory regimes. Woody cover showed a strong positive dependence on MAP between 200 and 700 mm, but no dependence on MAP above this threshold when the effects of other predictors were accounted for. Fires served to reduce woody cover below rainfall‐determined levels. Woody cover showed a complex, non‐linear relationship with total soil phosphorus, and was negatively correlated with clay content. There was a strong negative dependence of woody cover on soil nitrogen (N) availability, suggesting that increased N‐deposition may cause shifts in savannas towards more grassy states. Elephants, mixed feeders and browsers had negative effects on woody cover. Grazers, on the other hand, depressed woody cover at low biomass, but favoured woody vegetation when their biomass exceeded a certain threshold. Main conclusions Our results indicate complex and contrasting relationships between woody cover, rainfall, soil properties and disturbance regimes in savannas, and suggest that future environmental changes such as altered precipitation regimes, N‐enrichment and elevated levels of CO₂ are likely to have opposing, and potentially interacting, influences on the tree–grass balance in savannas.     

A revision of the structure of cucurbitacin S from Bryonia dioica

¹H NMR studies at 400 MHz on cucurbitacin S and its derivatives suggest that the structure of cucurbitacin S previously isolated from Bryonia dioica should be revised from (22S)-22, 25-anhydro-2,16α,22,25-tetrahydroxy-3,11,23-trioxo-cucurbita-1,5-diene to (24S)-16,24-anhydro- 2,16α,24,25-tetrahydroxy-3,11,22-trioxo-cucurbita-1,5-diene.