Leucasin, a triterpene saponin from Leucas nutans.

A new saponin, leucasin, has been isolated from Leucas nutans and characterized on the basis of chemical investigation and spectroscopic studies as 3-O-[β- -glucopyranosyl(1→2)β- -glucopyranosyl]2,3β-dihydroxylup-20(29)-ene. Lupeol palmitate, sitosterol and stigmasterol were also isolated.     

Leucasin, a triterpene saponin from Leucas nutans

A new saponin, leucasin, has been isolated from Leucas nutans and characterized on the basis of chemical investigation and spectroscopic studies as 3-O-[β- -glucopyranosyl(1→2)β- -glucopyranosyl]2α,3β-dihydroxylup-20(29)-ene. Lupeol palmitate, sitosterol and stigmasterol were also isolated.     

Macrophylloside, a flavone glucoside from Primula macrophylla

A new flavone glucoside macrophylloside has been isolated from the whole plant of Primula macrophylla and its structure was determined by spectroscopic methods as 2′-hydroxy-7-O-β- -glucopyranosyloxyflavone. Sitosterol glucoside was also isolated for the first time from this plant.     

Colonization factors of diarrheagenicE. coli and their intestinal receptors

WhileEscherichia coli is common as a commensal organism in the distal ileum and colon, the presence of colonization factors (CF) on pathogenic strains ofE. coli facilitates attachment of the organism to intestinal receptor molecules in a species- and tissue-specific fashion. After the initial adherence, colonization occurs, and the involvement of additional virulence determinants leads to illness. EnterotoxigenicE. coli (ETEC) is the most extensively studied of the five categories ofE. coli that cause diarrheal disease, and has the greatest impact on health worldwide. ETEC can be isolated from domestic animals and humans. The biochemistry, genetics, epidemiology, antigenic characteristics, and cell and receptor binding properties of ETEC have been extensively described. Another major category, enteropathogenicE. coli (EPEC), has virulence mechanisms, primarily effacement and cytoskeletal rearrangement of intestinal brush borders, that are distinct from ETEC. An EPEC CF receptor has been purified and characterized as a sialidated transmembrane glycoprotein complex directly attached to actin, thereby associating CF-binding with host-cell response. Three, additional categories ofE. coli diarrheal disease, their colonization factors and their host cell receptors are discussed. It appears that biofilms exist in the intestine in a manner similar to oral bacterial biofilms, and thatE. coli is part of these biofilms as both commensals and pathogens.Abbreviations CF colonization factor - CFA Colonization Factor Antigen - CS coli-surface-associated antigen - EAggEC enteroaggregativeE. coli - ECDD E. coli diarrheal disease - EHEC enterohemorrhagicE. coli - EIEC enteroinvasiveE. coli - EPEC enteropathogenicE. coli - ETEC enterotoxigenicE. coli - Gal galactose - GalNAc N-acetyl galactosamine - LT heat-labile toxin - NeuAc N-acetyl neuraminic acid - PCF Putative colonization factor - RBC red blood cells - SLT Shiga-like toxin - ST heat-stable toxin     

Localization of kallikrein in the guinea-pig submandibular gland

The localization of kallikrein in the acinar and the ductal components of the guinea-pig submandibular gland was investigated by a microdissection technique and an esterase assay. The results indicated that a major portion of the kallikrein is located in the striated duct cells. These results disagree with previous studies in the guinea-pig but are consistent with findings in the rat and cat submandibular gland.     

Aphid population abundance and pestiferous effect on various bean plant species

The population abundance, infestation, and harmful effects of the aphid Aphis craccivora Koch (Hemiptera: Aphididae) were studied on four bean plant species, namely the country bean (Lablab purpureus var. BARI Seem 1), the yard‐long bean (Vigna sesquipedalis var. BARI Borboti 1), the hyacinth bean (Dolichos lablab var. BARI Seem 6), and the bush bean (Phaseolus vulgaris var. BARI Jar Seem 3). Aphid abundance and infestation on the leaves, inflorescences, flowers, and pods differed significantly among the bean plant species, with P. vulgaris and V. sesquipedalis having the lowest and highest results, respectively. Aphid severity grade and the number of trichomes of the bean plant species were negatively correlated. The duration of the growth stages among the bean plant species were significantly different, with V. sesquipedalis having the shortest durations. Aphid abundance and infestation significantly affected the physical and phytochemical characteristics of the bean plant species. The highest reduction of number of leaves, flower inflorescences, and pod inflorescences per plant, and moisture and chlorophyll content in the leaves was found in L. purpureus. The results for V. sesquipedalis revealed the highest reduction in plant height, seed weight, and pH, while those of D. lablab showed the highest reduction in leaf area.     

Allelopathy and its coevolutionary implications between native and non‐native neighbors of invasive Cynara cardunculus L.

Invasive plants apply new selection pressures on neighbor plant species by different means including allelopathy. Recent evidence shows allelopathy functions as remarkably influential mediator for invaders to be successful in their invaded range. However, few studies have determined whether native and non‐native species co‐occurring with invaders have evolved tolerance to allelopathy. In this study, we conducted germination and growth experiments to evaluate whether co‐occurring native Juncus pallidus and non‐native Lolium rigidum species may evolve tolerance to the allelochemicals induced by Cyanara cardunculus in Australian agricultural fields. The test species were germinated and grown in pots filled with collected invaded and uninvaded rhizosphere soil of C. cardunculus with and without activated carbon (AC). Additionally, a separate experiment was done to differentiate the direct effects of AC on the test species. The soil properties showed invaded rhizosphere soils had higher total phenolic and lower pH compared with uninvaded soils. We found significant reduction of germination percentage and seedling growth in terms of above‐ and belowground biomass, and maximum plant height and root length of native in the invaded rhizosphere soil of C. cardunculus, but little effect on non‐native grass species. Even soil manipulated with AC showed no significant differences in the measured parameters of non‐native except aboveground biomass. Taken together, the results indicate allelochemicals induced by C. cardunculus exert more suppressive effects on native than non‐native linking the coevolved tolerance of those.     

Analysis of mitochondrial protein‐coding genes of Antheraea assamensis: Muga silkworm of Assam

To understand the synonymous codon usage pattern in mitochondrial genome of Antheraea assamensis, we analyzed the 13 mitochondrial protein‐coding genes of this species using a bioinformatic approach as no work was reported yet. The nucleotide composition analysis suggested that the percentages of A, T, G,and C were 33.73, 46.39, 9.7 and 10.17, respectively and the overall GC content was 19.86, that is, lower than 50% and the genes were AT rich. The mean effective number of codons of mitochondrial protein‐coding genes was 36.30 and it indicated low codon usage bias (CUB). Relative synonymous codon usage analysis suggested overrepresented and underrepresented codons in each gene and the pattern of codon usage was different among genes. Neutrality plot analysis revealed a narrow range of distribution for GC content at the third codon position and some points were diagonally distributed, suggesting both mutation pressure and natural selection influenced the CUB.     

Determination of acid α-naphthyl acetate esterase enzyme activity in peripheral blood leukocytes of gazelles (Gazella subgutturosa)

We examined gazelle peripheral blood leucocytes using the α-Naphthyl acetate esterase (ANAE) staining technique (pH 5.8). Our purpose was to determine the percentage of ANAE positive lymphocytes. The proportion of ANAE positive T-lymphocytes was 72%. T-lymphocytes showed an ANAE positive reaction, but eosinophilic granulocytes and monocytes also showed a positive reaction. By contrast, no reaction was detected in B-lymphocytes, neutrophil granulocytes or platelets. The reaction observed in T-lymphocytes was a red-brown coloration, usually 1–2 granules, but enough granules to fill the cytoplasm were detected rarely. As a result of ANAE enzyme staining, we concluded that the staining technique can be used as a cytochemical marker for gazelle T-lymphocytes.