Fine structure of Chloromyxum menticirrhi n. sp. (Myxozoa) infecting the urinary bladder of the marine teleost Menticirrhus americanus (Sciaenidae) in Southern Brazil

A myxosporidian was found in the urinary bladder of the teleost Menticirrhus americanus Linnaeus, 1758 (Sciaenidae) collected from the South Atlantic coast of Brazil. Polysporic amoeboid plasmodia containing sporoblasts, developing pansporoblasts and spores were free in the bladder lumen. The prevalence of infection was 17.64% (15/85). Unfixed spores were spherical to subspherical, on average 10.5 μm long, 9.8 μm wide and 10.1 μm thick (n=25), and fixed spores measured 10.1×9.5×9.7 μm. The two spore valves were of equal size and each possessed prominent sutural lines and about 41 (37–45) surface ridges aligned parallel with the suture line. These ridges gave transverse sections a cog-wheel-like outline. The spores contained four pyriform polar capsules of equal size (3.20×2.0 μm) (n=25) (fixed), each with a polar filament having 3–4 (rarely 5) coils. The binucleate sporoplasm was irregular in shape, with granular matrix and randomly distributed dense bodies. The shape and dimensions of the spore, as well as the number, position and arrangement of the surface ridges, polar capsules and polar filament indicate that this is a new species, herein designated Chloromyxum menticirrhi. The gill, liver, gall bladder and intestine of the host showed no abnormalities.     

A new record of Myxobolus brachysporus and M. israelensis in the tilapia (Oreochromis niloticus) collected from the Nile River,Egypt

The present study was carried out as part of an ongoing general survey for myxosporean parasites infecting tilapias in the River Nile, Egypt. In the present study, 77 Nile tilapia (Oreochromis niloticus) were collected from boat landing sites at Beni-Suef governorate, Egypt and examined for the myxosporean infection. The infection was encountered as a huge number of free spores in the kidney and the spleen. The infection showed a prevalence of 51.9% (40/77) for Myxobolus brachysporus while it was 25.9% (20/77) for Myxobolus israelensis. Mature spores of M. brachysporus were ellipsoidal and measured 8.6 × 13.2 μm. The polar capsules were subcircular with 5–6 filament turns and measured 4.7 × 3.6 μm. Spores of M. israelensis were ellipsoidal in the frontal view and fusiform in the lateral view. Spore measurements were 13.4 μm long and 8.7 μm wide. The polar capsules were elongated with 6–7 filament coils and measured 8.6 × 3.1 μm. The findings presented here proved that tilapia fishes in the Nile River are still suffering from infections with Myxobolus species. Therefore, further studies should be carried out to survey the Myxobolus infection among tilapias under culture conditions to clarify the pathological impacts of this parasite in tilapias aquaculture.     

Morphology and phylogeny of Henneguya jocu n. sp. (Myxosporea,Myxobolidae), infecting the gills of the marine fish Lutjanus jocu

Henneguya jocu n. sp. (Myxosporea, Myxobolidae) is described from the gill lamellae of the marine teleost fish Lutjanus jocu, with a focus on ultrastructural and molecular features. This myxosporean forms subspherical cysts up to ∼260 μm × 130 μm long, and develops asynchronously. Mature myxospores ellipsoidal with a bifurcated caudal process. Myxospore length 10.9 ± 0.4 μm (n = 50); width, 8.2 ± 0.3 μm (n = 50); and thickness, 2.9 ± 0.5 μm (n = 50). Two equal caudal processes, 34.1 ± 1.0 μm long (n = 50); and total myxospore length, 45.2 ± 1.0 μm (n = 50). Two symmetric valves surround two ellipsoidal polar capsules, 5.0 ± 0.3 × 1.4 ± 0.2 μm (n = 20), each containing an isofilar polar filament forming 4–5 coils along the inner wall of these structures, as well as a binucleated sporoplasm presenting a spherical vacuole and several globular sporoplasmosomes. Both the morphological data and molecular analysis of the SSU rDNA gene identify this parasite as a new species of the genus Henneguya. Maximum Likelihood and Maximum Parsimony analyses further indicate that the parasite clusters within others marine Myxobolidae species, forming a group alongside other Henneguya species described from marine hosts.     

Supplementary studies and molecular data on Henneguya cerebralis Pronin, 1972 (Myxozoa: Myxosporea), a parasite from Kosogol grayling Thymallus arcticus nigrescens in Mongolia

Henneguya cerebralis Pronin, 1972 (Myxozoa) was described from Kosogol graylings Thymallus arcticus nigrescens Dorogostaisky, 1923 in Lake Khovsgol (Mongolia) in 1972.H. cerebralis was redescribed using critical morphological features and 18S ribosomal DNA (rDNA) gene sequence. Parasite infects cranial cartilage of fish host. Plasmodia are white rounded or ovoid, by 0.1 to 2 mm in size, containing large quantities of spores. Spore body is ovoid or rounded, 11.18 ± 0.13 μm (range 9,71–12,56) in length and 9.06 ± 0.16 μm (range 7.22–10,06) in width with equal polar capsules (4.7 × 2.6 μm). The two caudal appendages have different lengths (one of them was shorter in 20%).Phylogenetic position inferred by 18S rDNA shows that H. cerebralis is closely related with H. zschokkei, H. nuesslini, H. salminicola and H. cartilaginis which are histozoic parasites of salmonid fish.     

Exogenous and endogenous stages of Eimeria perforans naturally infected domestic rabbit (Oryctolagus cuniculus) in Saudi Arabia: Light microscopic study

Exogenous and endogenous stages of Eimeria perforans naturally infected rabbits in Saudi Arabia were described. The prevalence of infection was 75%. Oocysts were ovoid to elliptical and measured 16 × 10 μm. The four dizoic sporocysts were ovoid and measured 7 × 5 μm. Endogenous stages were restricted to the duodenum. Meronts, microgamonts, macrogamonts and young oocysts were recorded and described.     

Glomerella truncata sp. nov., the teleomorph of Colletotrichum truncatum

Anthracnose of lentil, caused by Colletotrichum truncatum is a serious threat to lentil (Lens culinaris) grown in western Canada. The teleomorph stage of this pathogen was induced to form under laboratory conditions. Random pairing of single conidium isolates enabled the identification of fertile isolates. The individual isolates of this fertile pair were crossed with 14 other isolates, and all isolates were also incubated alone. Self-sterility was observed for all 16 isolates tested. Three isolates did not produce perithecia with either tester isolate, and none of the isolates tested produced perithecia with both tester isolates. Perithecia were brown–black, superficial, solitary or in small groups, obpyriform to ovate or ampulliform, 200–520 × 110–320 μm (mean: 350 × 200 μm). Asci were cylindrical, narrowing slightly at the apex, unitunicate, evanescent, 53–142 × 5–14 μm (mean: 90 × 8 μm), and contained eight ascospores. Ascospores were hyaline, aseptate, oblong, 12–20 × 5–8 μm (mean: 15.7–6.7 μm). The characteristics agree with those described for the genus Glomerella, and the species was named G. truncata sp. nov. The morphology of the new species is compared with that of other species in the genus, and future research on G. truncata is described.     

Glomus drummondii and G. walkeri,two new species of arbuscular mycorrhizal fungi (Glomeromycota)

Two new ectocarpic arbuscular mycorrhizal fungal species, Glomus drummondii and G. walkeri (Glomeromycota), found in maritime sand dunes of northern Poland and those adjacent to the Mediterranean Sea are described and illustrated. Mature spores of G. drummondii are pastel yellow to maize yellow, globose to subglobose, (58–)71(–85) μm diam, or ovoid, 50–80 × 63–98 μm. Their wall consists of three layers: an evanescent, hyaline, short-lived outermost layer, a laminate, smooth, pastel yellow to maize yellow middle layer, and a flexible, smooth, hyaline innermost layer. Spores of G. walkeri are white to pale yellow, globose to subglobose, (55–)81(–95) μm diam, or ovoid, 60–90 × 75–115 μm, and have a spore wall composed of three layers: a semi-permanent, hyaline outermost layer, a laminate, smooth, white to pale yellow middle layer, and a flexible, smooth, hyaline innermost layer. In Melzer's reagent, only the inner- and outermost layers stain reddish white to greyish rose in G. drummondii and G. walkeri, respectively. Both species form vesicular–arbuscular mycorrhizae in one-species cultures with Plantago lanceolata as the host plant. Phylogenetic analyses of the ITS and parts of the LSU of the nrDNA of spores placed both species in Glomus Group B sensu Schüßler et al. [Schüßler A, Schwarzott D, Walker C, 2001. A new fungal phylum, the Glomeromycota: phylogeny and evolution. Mycolological Research 105: 1413-1421.]     

Biomorphometric characteristics of different types of sensilla detected on the antenna of Helicoverpa armigera by scanning electron microscopy

A morphometric study on H. armigera antenna showed four styles of sensilla, i.e., styloconica, chaetica, coeloconica, and trichodea, and their numbers were estimated. Sensilla trichodea detect inter and intraspecific communication signals and was the most numerous. They were divided into three types: type I, the longest, with a length of 34.04 ± 3.16 μm and about 2.16 to 2.42 μm in diameter at its base; 2) type II, intermediate, with a length of 22.58 ± 0.77 μm and basal diameter of 1.8–2.52 μm; 3) type III, the shortest sensilla trichodea, with a length of 7.62 ± 0.4 μm and a range in diameter similar to that of type II. The length of the female sensilla trichodea was longer than that of the male. The total number of sensilla trichodea was estimated to be 7520 on the antenna of the female, and 6831 on the male antenna. The lengths of the sensilla trichodea type I and type III were significantly different on male (t = 4.6881, P = 0.0034) and female antenna (t = 18.9852, P = 0.0001). An estimation of the predicted surface area of the most numerous type I on sampled segments between the 12th and 20th segments from a female of H. armigera showed a surface area of 5 × 10³ μm² and a sensillar density of 38 sensilla/10³ μm². The fraction of sensilla-occupied surface area was 0.4 μm².     

Ultrastructure and phylogeny of Glugea arabica n. sp. (Microsporidia), infecting the marine fish Epinephelus polyphekadion from the Red Sea

A new microsporidian species, Glugea arabica n. sp., is reported infecting the intestinal wall of the marine teleost Epinephelus polyphekadion (=microdon) collected from the Red Sea coast off Saudi Arabia, and described on the basis of microscopic and molecular procedures. Spherical blackish xenomas formed parasitophorous vacuoles completely packed with several parasitic developmental stages, including spores. The nuclei were monokaryotic in all developmental stages. Spores were ellipsoidal to pyriform and measured 6.3 ± 0.3 (5.9–6.6) μm in length and 3.3 ± 0.4 (2.9–3.7) μm in width. A lamellar polaroplast surrounded the uncoiled portion of the polar filament, which extended into the spore's posterior pole and formed 27–29 coils organized in three or four rows. The posterior vacuole, located at the spore's posterior pole, appeared surrounded by the polar filament coils and displayed an irregular matrix composed of light material, in which was located the posterosome. Molecular analysis of the rRNA genes, including the ITS region, was performed using maximum parsimony, neighbor-joining and maximum likelihood methodologies. The ultrastructural features observed, in combination with the molecular data analysed, suggests the parasite to be a new species of the genus Glugea.     

Serotonin transporter protein (SERT) and P-glycoprotein (P-gp) binding activity of montanine and coccinine from three species of Haemanthus L. (Amaryllidaceae)

The alkaloid rich extracts from an acid/base extraction of bulb material of Haemanthus coccineus L., H. montanus Baker and H. sanguineus Jacq. revealed that two montanine type Amaryllidaceae alkaloids, montanine (1) and coccinine (2) were the major alkaloid constituents. Together these two alkaloids constituted 88, 91 and 98% of the total alkaloid extract from each species respectively. GC–MS analysis revealed that H. coccineus and H. sanguineus had a relative abundance of coccinine (74 and 91% respectively) to montanine (14 and 7% respectively); whereas H. montanus had 20% coccinine and 71% montanine. The three extracts and two isolated alkaloids were evaluated for binding to the serotonin transporter protein (SERT) in vitro. Affinity to SERT was highest in H. coccineus (IC₅₀ = 2.0 ± 1.1 μg/ml) followed by H. montanus (IC₅₀ = 6.8 ± 1.0 μg/ml) and H. sanguineus (IC₅₀ = 28.7 ± 1.1 μg/ml). Montanine (IC₅₀ = 121.3 ± 3.6 μM or 36.56 ± 1.14 μg/ml; K_i = 66.01 μM) was more active than coccinine (IC₅₀ = 196.3 ± 3.8 μM or 59.15 ± 1.08 μg/ml; K_i = 106.8 μM), both of which were less active than the total alkaloid extracts of each species investigated. The possible synergistic effects of two coccinine/montanine mixtures (80:20 and 20:80) were investigated, however the mixtures gave similar activities as the pure compounds and did not show any increase in activity or activity similar to the total alkaloid extracts. Thus the considerably higher activity observed in the total alkaloid extracts is not correlated to the relative proportions of coccinine and montanine in the extracts and thus are likely to be due to more potent unidentified minor constituents. Both alkaloids exhibited low binding affinity to P-glycoprotein (P-gp) as demonstrated by low inhibition of calcein-AM efflux in the MDCK-MDR1 cell line. This indicates that P-gp efflux will not be limiting for blood–brain-barrier passage of the alkaloids.     

Synthesis and biological evaluation of indole derivatives as α-amylase inhibitor

A series of twenty indole hydrazone analogs (1–21) were synthesized, characterized by different spectroscopic techniques such as ¹H NMR and EI-MS, and screened for α-amylase inhibitory activity. All analogs showed a variable degree of α-amylase inhibition with IC₅₀ values ranging between 1.66 and 2.65 μM. Nine compounds that are 1 (2.23 ± 0.01 μM), 8 (2.44 ± 0.12 μM), 10 (1.92 ± 0.12 μM), 12 (2.49 ± 0.17 μM), 13 (1.66 ± 0.09 μM), 17 (2.25 ± 0.1 μM), 18 (1.87 ± 0.25 μM), 20 (1.83 ± 0.63 μM), and 19 (1.97 ± 0.02 μM) showed potent α-amylase inhibition when compared with the standard acarbose (1.05 ± 0.29 μM). Other analogs showed good to moderate α-amylase inhibition. The structure activity relationship is mainly focusing on difference of substituents on phenyl part. Molecular docking studies were carried out to understand the binding interaction of the most active compounds.     

Description of two new Drepanomonas taxa and an account on features defining species in Drepanomonas Fresenius, 1858 (Ciliophora,Microthoracida)

Using standard methods, we describe two new Drepanomonas taxa: Drepanomonas hymenofera (Horváth 1956) nov. comb., which is composed of two (biogeographical?) subspecies, viz., D. hymenofera venezuelensis nov. subspec. and D. hymenofera hymenofera (Horváth 1956), was discovered in soil from Venezuela and Iceland, respectively. Both are comparatively large-sized (50 × 20 μm and 40 × 18 μm in vivo), differing in the cortex pattern and the structure of kineties 3 and 4. We agree with Corliss (1979) and Chardez (1990) that the genus Pseudocristigera, which was established by Horváth (1956) for Drepanomonas hymenofera, is a junior synonym of Drepanomonas. Drepanomonas vasta nov. spec., which was discovered in the mud of a tree hole in Austria, is a middle-sized species (35 × 18 μm) with thick body, wide left side ridges, a single anterior dikinetid in kinety 4, and an average of 99 basal bodies; it is unique in having the dorsal side much more flattened than the ventral side, thus being cuneate in transverse view. Ontogenetic data show that the ciliary pattern of Drepanomonas is homologous to that of Leptopharynx, specifically, the structure and origin of the postoral complex. Main features for distinguishing Drepanomonas species are discussed.     

Sources of variation contributing to production and quality attributes of Kyrgyz cashmere in Osh and Naryn provinces: Implications for industry development

We aimed to quantify the sources of variation contributing to the production and quality of cashmere produced in five districts in Osh and Naryn provinces of Kyrgyzstan. In early spring 2008 mid-side cashmere samples were taken from 719 cashmere adult females, and 41 cashmere adult males and castrates. Samples came from 53 villages and a total of 156 farmers’ flocks. For 91 goats from 33 farmers in 13 villages of two districts that had been sampled earlier, cashmere was combed from the goat at the time of a second visit (end of April 2008) when the cashmere would normally be harvested. Following standard cashmere objective measurement, data were examined using general linear modelling to quantify the effects of potential determinants. The mean fibre diameter (MFD) of cashmere differed between provinces (Osh 15.7 μm, Naryn 16.7 μm; P = 4.4 × 10⁻²⁰). About 42% of the cashmere was <16 μm, 48% was 16.0–18.0 μm and 9.5% was >18.0 μm. Most of the cashmere samples were coloured (81%), with 63% black and 19% white. The percentage of cashmere samples that were white declined as MFD increased (26% < 14 μm to 11% of >18 μm). The primary determinants of cashmere MFD of individual goats were age of goat (range 1.46 μm, P = 1.8 × 10⁻¹²) and farm (range 6.5 μm, P = 1.7 × 10⁻¹⁴). The lesser effects detected for sex (range 0.9 μm, P = 0.026) and colour of cashmere (range 1.8 μm, P = 0.023) were based on small sample sizes and are unreliable. Age of goat had important affects on fibre diameter variation (up to 1.7% in coefficient of variation, P = 5.8 × 10⁻⁶) and fibre curvature (2.5–5°/mm, P = 2.1 × 10⁻⁴). By far the greatest effect on fibre curvature was cashmere MFD (P = 3.0 × 10⁻¹⁰⁴) with a smaller effect of sex (about 5°/mm, P = 3.0 × 10⁻⁶). Village effects were detected on fibre diameter variability (range 4.5% in coefficient of variation, P = 0.027) and fibre curvature (range 15°/mm, P = 1.6 × 10⁻⁷). There was a strong negative association between increasing MFD and declining fibre curvature (−5.11 ± 0.181°/mm per 1 μm; P = 7.1 × 10⁻¹²¹; r² = 0.51). Average combed cashmere weight was 164 g, the clean cashmere content was 0.661 and median clean cashmere production was 110 g per goat (range 60–351 g). Combed cashmere production increased with altitude of the village, probably related to different moulting times as spring temperatures warmed up later in higher altitude villages up to 3200 masl. Measurements of combed cashmere MFD were coarser than the mid-side samples taken earlier in the year. There are farmers and cashmere goats in the sampled districts of Kyrgyzstan which produce the finest qualities of commercial cashmere as the vast majority of cashmere is fine, has low variation in fibre diameter and has fibre crimping (curvature) typical of Chinese and Mongolian cashmere. There is substantial scope to increase the production and commercial value of cashmere produced by Kyrgyz goats. In particular, some villages and farmers need to change their buck selection practices if they wish to produce acceptable cashmere. Farmers should separate their finer and white cashmere prior to sale.     

Experimental infection of red dwarf honeybee,Apis florea,with Nosema ceranae

This research is the first record of the infection of Apis florea by Nosema ceranae, a newly identified pathogen of honeybee in Thailand which was initially isolated from A. florea workers. Each Nosema free-bee was fed 2 μl of 50% (w/v) sucrose solution containing 0, 10,000 20,000 or 40,000 Nosema spores/bee. The survival rates of treated bees were significantly lower compared to control bees. Infectivity was not statistically different among the three spore concentrations, whereas no infection was found in control bees. Protein content of control bee hypopharyngeal glands 14 days post inoculation (p.i) was significantly higher (21.47 ± 0.17 mg/bee) compared to all treatments. The infection ratio of bees treated with 40,000 spores/bee increased with time after inoculation. These results suggest that N. ceranae has a significant negative effect on honeybee hypopharyngeal gland protein production and contributes to their shortened life span.     

Alkaloids from the roots of Stemona javanica (Kunth) Engl. (Stemonaceae) and their anti-malarial,acetylcholinesterase inhibitory and cytotoxic activities

Two new protostemonine-type alkaloids, javastemonine A and B (3 and 4) have been isolated from the root extracts of Stemona javanica together with four known Stemona alkaloids, 13-demethoxy-11(S*),12(R*)-dihydroprotostemonine (1), isoprotostemonine (2), protostemonine and isomaistemonine. The structures and relative configurations of the new alkaloids were determined by spectroscopic analysis. The alkaloids 1 and 2 and protostemonine showed moderated antiplasmodial activities against the Plasmodium falciparum strains, TM4 (IC₅₀ values of 17.7 ± 3.7, 16.8 ± 5.4, 16.0 ± 4.2 μg/mL, respectively) and K1 (IC₅₀ values of 16.8 ± 3.1, 14.1 ± 3.7, 11.9 ± 3.3 μg/mL, respectively). These compounds showed no significant cytotoxicities against KB or Vero cells or acetylcholinesterase inhibitory activities.     

Morphological and molecular characterization of Thelohanellus macrovacuolaris n. sp. (Myxosporea: Bivalvulida) infecting the palate in the mouth of common carp Cyprinus carpio L. in China

Thelohanellus macrovacuolaris n. sp. is described during a survey on myxozoan diversity of common carp Cyprinus carpio L. in China. It is characterized by the presence of round or ellipsoidal plasmodium in the palate in the mouth of host. Mature spores were pyriform in frontal view, lemon shaped in lateral view, measuring 21.6 ± 0.9 (19.3–23.8) long, 12.5 ± 0.7 (10.3–13.6) wide, and 10.2 ± 0.4 (9.8–11.8) thick. Most spores were surrounded by the membrane sheath. Single polar capsule was round with an apophysis at its top end presented close to apex of spore, measuring 9.1 ± 0.6 (8.0–10.0) in length, 8.6 ± 0.5 (7.8–9.6) in width. Polar filaments coiled, with 7 to 8 turns. A large, round iodinophilous vacuole was present, with 5.8–7.5 in diameter. The present species is morphologically distinct from all other Thelohanellus species. The BLAST search indicated that the newly obtained small subunit ribosomal RNA (ssrRNA) gene sequence of T. macrovacuolaris n. sp. did not match any available sequences in GenBank. Phylogenetically, T. macrovacuolaris n. sp. was placed sister to Thelohanellus wangi in the Thelohanellus clade. Both morphology and ssrRNA gene sequence data revealed that the present parasite is a new species of genus Thelohanellus.     

Two new “flagship” ciliates (Protozoa,Ciliophora) from Venezuela: Sleighophrys pustulata and Luporinophrys micelae

Sleighophrys pustulata nov. gen., nov. spec. and Luporinophrys micelae nov. gen., nov. spec. were discovered in a slightly saline mud and soil sample from some flat, dry puddles in the Maracay National Park on the north coast of Venezuela. Their morphology was studied in vivo, in protargol preparations, and in the scanning electron microscope. The new genera are monotypic and belong to the trachelophyllid haptorids. They are characterized by the unique shape of the epicortical scales (lepidosomes). Sleighophrys pustulata, which has a size of about 180×23 μm, possesses type I and unique type V lepidosomes which are hat-shaped and about 7×7 μm in size. Luporinophrys micelae, which has a size of about 200×35 μm, possesses types I, II, and unique type VI lepidosomes which are narrow, about 10 μm high cones composed of fibrous stripes connected by polygonal meshes. The conspicuous body size and the richly structured, comparatively large lepidosomes make S. pustulata and L. micelae biogeographic flagships which may help to cast some light on the pending question whether or not microorganisms have biogeographies. The available data suggest that both species have a restricted geographic distribution, not only because they were not described previously, but mainly because they were absent in about 2000 freshwater samples from central Europe and in about 1000 soil samples collected globally.     

Horseradish peroxidase production from Spodoptera frugiperda larvae: A simple and inexpensive method

Horseradish peroxidase is used in many biotechnological fields including diagnostics, biocatalysts and biosensors. Horseradish peroxidase isozyme C (HRPC) was extracellularly expressed in Spodoptera frugiperda Sf9 cell culture and in intact larvae. At day 6 post-infection, the concentration of active HRPC in suspension cultures was 3.0 ± 0.1 μg per 1 × 10⁶ cells or 3.0 ± 0.1 mg l⁻¹ with a multiplicity of infection of 1 in the presence of 7.2 μM hemin. Similar yields were obtained in monolayer cultures. In larvae, the HRPC expression level was 137 ± 17 mg HRPC kg⁻¹ larvae at day 6 post-infection with a single larvae thus producing approximately 41 μg HRPC. The whole larval extract was separated by ion exchange chromatography and HRPC was purified in a single step with a yield of 75% and a purification factor of 117. The molecular weight of recombinant HRPC was 44,016 Da, and its glycosylation pattern agreed with that expected for invertebrates. The K_m and V_max were 12.1 ± 1.7 mM and 2673 ± 113 U mg⁻¹, respectively, similar to those of HRP purified from Armoracia rusticana roots. The method described in this study, based on overexpression of HRPC in S. frugiperda larvae, is a simple and inexpensive way to obtain high levels of active enzyme for research and other biotechnological applications.     

Synthesis,biological evaluation and molecular docking study of N-arylbenzo[d]oxazol-2-amines as potential α-glucosidase inhibitors

A novel series of N-arylbenzo[d]oxazol-2-amines (4a–4m) were synthesized and evaluated for their α-glucosidase inhibitory activity. Compounds 4f–4i, 4k and 4m displayed potent inhibitory activity against α-glucosidase with IC₅₀ values in the range of 32.49 ± 0.17–120.24 ± 0.51 μM as compared to the standard drug acarbose. Among all tested compounds, compound 4g having 4-phenoxy substitution at the phenyl ring was found to be the most active inhibitor of α-glucosidase with an IC₅₀ value of 32.49 ± 0.17 μM. Analysis of the kinetics of enzyme inhibition indicated that compound 4g is a noncompetitive inhibitor of α-glucosidase with a K_i value of 31.33 μM. Binding interaction of compound 4g with α-glucosidase was explored by molecular docking simulation.     

Study of folliculogenesis in vivo in guinea pig

Understanding normal folliculogenesis in guinea pigs is fundamental as a first step towards the development of a guinea pig follicle culture system. The aims of this study were (1) to characterise morphological changes during follicular development in vivo and (2) to describe the growth pattern of follicles. Cycling guinea pigs were infused with 5-bromo-2′-deoxyuridine for 1 or 2 weeks and sacrificed at time points ranging from 0 to 37 days after the infusion. The granulosa cell number in the largest cross-sections increased from 25.0 ± 6.1 (mean ± S.D.) in primary (type 2) to 192.0 ± 65.9 in preantral (type 5) and 256.3 ± 96.9 in antral (type 6) follicles. The oocyte diameter increased from 44.8 ± 6.2 μm (type 2) to 72.8 ± 9.1 μm (type 5) and 78.9 ± 9.3 μm (type 6) and the follicle diameter from 67.9 ± 10.1 μm (type 2) to 188.9 ± 29.7 μm (type 5) and 231.0 ± 56.1 μm (type 6). After a 1-week labelling period, about 71% of type 2 follicles had at least one labelled granulosa cell, as did 95% of type 3–4, and 100% of type 5 and 6. About 1 week was needed to achieve 95% mitotic activity in granulosa cells (GC) of type 5 and 6 follicles, while about 2 weeks was required to achieve 100% mitotic activity in GC of type 3–4 and more than 2 weeks for GC of type 2 follicles. These data provide some baselines for the examination of a guinea pig follicle culture system.