Vegetation composition differentiation and species-environment relationships in the northern part of Isfahan Province,Iran

A considerable proportion of Iran's territory is covered with arid and semi-arid rangelands and mismanagement and overexploitation of those rangelands have resulted in serious ecological degradation. Thus, the need is pressing to examine the present species composition and the relationships with environmental factors for providing the needed scientific references to species conservation and ecological rehabilitation efforts. The aims of this study were to examine the species composition and to delineate the most important factors influencing the distributions of plant species and groups in the northern rangelands of Isfahan Province(Iran) using two-way indicator species analysis(TWINSPAN), detrended correspondence analysis(DCA), principal component analysis(PCA), and canonical correspondence analysis(CCA). Field investigations were conducted in the growing season of 2014 using stratified random method in 22 homogeneous sampling units. In total, 75 plant species belonging to 52 genera and 19 families were identified. The most important families were Asteraceae and Papilionaceae, the most important genera were Astragalus, Cousinia, and Acanthophyllum, and the most important species were Artemisia aucheri and Artemisia sieberi. Plant species were classified into 10 groups using TWINSPAN. DCA was used to estimate the magnitude of changes in species composition along the first two ordination axes to provide gradient length estimations for PCA and CCA ordinations. The first three PCA axes and the first three CCA axes demonstrated similar cumulative percentage of variance, indicating that the environmental factors(selected by PCA) used in CCA ordination were acceptable for explaining the species composition and the distributions. CCA ordination showed that the first axis was closely related to elevation, slope, surface bare soil cover, surface litter cover, gravel proportion, organic matter, total nitrogen, Ca CO3 content, and grazing intensity and that the second axis was closely related to sand proportion, silt proportion, clay proportion, and saturation percentage. Among these factors, elevation was the most effective factor to separate the plant groups and grazing was the major cause of rangeland degradation.     

Protease in sturgeon sperm and the effects of protease inhibitors on sperm motility and velocity

In mammals, proteases are present in sperm acrosome and play key role in fertilization. Sturgeon sperm has an acrosome, but its physiology, biochemistry, and potential role in fertilization are unknown. In the present study, we have observed high protease activity in acidic extract of intact sperm compared to that of seminal plasma in sterlet (Acipenser ruthenus). The protease activity was decreased and increased in acidic extract of motility-activated sperm and in the activation medium, respectively. Molecular analysis revealed total protease and serine (acrosin) protease activities in sperm acidic extract which was accumulated in a protein band with relative molecular mass of 35 kDa. Immunoelectron microscopy using an affinity-purified polyclonal antibody for boar acrosin localized the protease at the acrosome region. Moreover, initiation of sperm motility was inhibited after activation in the presence of inhibitors for both trypsin-like and chymotrypsin-like proteases, while the effects of protease inhibitors on sperm velocity were uncertain. Our results indicate similarities in physiology and biochemistry of acrosome between sturgeon and mammals and suggest potential role of protease in the initiation of sperm motility in sturgeon.     

Anti-acetylcholinesterase, anti-α-glucosidase, anti-leishmanial and anti-fungal activities of chemical constituents of Beilschmiedia species

Phytochemical investigation of Beilschmiedia alloiophylla has resulted in the isolation of one new alkaloid, 2-hydroxy-9-methoxyaporphine (1), and ten known natural products, laurotetanine (2), liriodenine (3), boldine (4), secoboldine (5), isoboldine (6), asimilobine (7), oreobeiline (8), 6-epioreobeiline (9), β-amyrone (10), and (S)-3-methoxynordomesticine (11). Chemical studies on the bark of B. kunstleri afforded compounds 2 and 4 along with one bisbenzylisoquinoline alkaloid, N-dimethylphyllocryptine (12). Structures of compounds 1-12 were elucidated on the basis of spectroscopic methods. All of these isolates were evaluated for their anti-acetylcholinesterase (AChE), anti-α-glucosidase, anti-leishmanial and anti-fungal activities. Compounds 1-12 exhibited strong to moderate bioactivities in aforementioned bioassays.     

Study of Chemical Composition and Efficacy of Different Extracts of Iranian Propolis on the Microbiological and Sensory Parameters of Minced Cyprinus carpio Meat at 4°C Storage

This study has evaluated the effects of different concentrations of the water and ethanolic extracts of Iranian propolis (WEP and EEP) on the microbiological and sensory parameters of minced common carp meat that was stored at 4°C for 9 days. The chemical compounds of the extracts were identified by gas chromatography–mass spectroscopy (GC-MS) analysis. The results revealed that WEP and EEP extracts were efficient against the spoilage microorganisms, including total plate counts (TPCs), psychrotrophic populations (PTCs), lactic acid bacteria (LAB), and even Staphylococcus aureus. There was a significant difference in the bacteria growth between samples treated with WEP or EEP and the control sample during storage. Inhibitory effects were, respectively, 7% EEP > 5% EEP > 3% EEP > 7% WEP > 5% WEP > 3% WEP. In all treatments, PTC counts were higher than 7 log CFU/g after 6 days as well as TPC, LAB, and S. aureus populations after 9 days. Overall, the results show that EEP and WEP have good antimicrobial activity due to high phenolic and flavonoid compounds, including caffeic acid, tectochrysin, aceacetin, chrysin, pinostrobin, pinobanksin-3-acetate, galangin-3-methyl ester, and pinocembrin chalcone. Sensory evaluation shows very slight improvement in sensory properties (color, odor, texture, and overall acceptability) of the treated samples with the different extracts of Iranian propolis.