Phytochemical study on Berberis sibirica Pall.

From the aerial parts (700g) of berberis sibirica pall. 6 isoquinoline alkaloids of protoberberine, protopine, benzophenantridine and proaporphine type were isolated. The known alkaloids (-)-tetrahydropseudocoptisine, pseudoprotopine, (+)-chelidonine and (+)-glaziovine are new for the family berberidaceae. from the aerial part ii (3.9 kg) 14 isoquinoline alkaloids of aporphine, proaporphine, protoberberine, protopine, benzylisoquinoline, bisbenzylisoquinoline,proaporphine-benzylisoquinoline and simple isoquinolin type were isolated and identified. The aporphine alkaloid 1-o-methylisotebaidine and simple isoquinoline dehydrocorypalline have been found for the first time in the family of berberidaceae. From the roots of b. sibirica 10 isoquinoline alkaloids of protoberberine, benzylisoquinoline, bisbenzylisoquinoline, aporphine-benzylisoquinoline and proaporphine-benzylisoquinoline type were isolated. 1,10-di-omethylpakistanine has been reported for the first time as a natural alkaloid. The known alkaloids (-) -isothalidezine and (+)-armepavine have been found for the first time in the family berberidaceae. All structures were determined by physical and spectral data.DOI: http://dx.doi.org/10.5564/mjc.v12i0.185 Mongolian Journal of Chemistry Vol.12 2011: 117-12

Alkaloids from Sedum telephium L.

The crude alkaloid mixtures from the aerial parts S.telephium was analyzed by GC-MS method. As a result 14 compounds, including 6 alkaloids were characterized. 3-methyl-2-carbethoxyindole (4.730%), 2-(2-hydroxyphenyl) benzothiazole (1.576%) and N,4, 5-trimethyl phenyl-1,2-diamine, (1.217%) were in higher contents. One sulfur-containing alkaloid 2-(2-hydroxyphenyl) benzothiazole has been identified. These six alkaloids are described for the first time from this plant.Mongolian Journal of Chemistry 16 (42), 2015, 44-4

Non-equivalence of Wnt and R-spondin ligands during Lgr5+ intestinal stem-cell self-renewal

The canonical Wnt/β-catenin signaling pathway governs diverse developmental, homeostatic and pathologic processes. Palmitoylated Wnt ligands engage cell surface Frizzled (Fzd) receptors and Lrp5/6 co-receptors enabling β-catenin nuclear translocation and Tcf/Lef-dependent gene transactivation1–3. Mutations in Wnt downstream signaling components have revealed diverse functions presumptively attributed to Wnt ligands themselves, although direct attribution remains elusive, as complicated by redundancy between 19 mammalian Wnts and 10 Fzds1 and Wnt hydrophobicity2,3. For example, individual Wnt ligand mutations have not revealed homeostatic phenotypes in the intestinal epithelium4, an archetypal canonical Wnt pathway-dependent rapidly self-renewing tissue whose regeneration is fueled by proliferative crypt Lgr5+ intestinal stem cells (ISCs)5–9. R-spondin ligands (Rspo1–4) engage distinct Lgr4-6 and Rnf43/Znrf3 receptor classes10–13, markedly potentiate canonical Wnt/β-catenin signaling and induce intestinal organoid growth in vitro and Lgr5+ ISCs in vivo8,14–17. However, the interchangeability, functional cooperation and relative contributions of Wnt versus Rspo ligands to in vivo canonical Wnt signaling and ISC biology remain unknown. Here, we deconstructed functional roles of Wnt versus Rspo ligands in the intestinal crypt stem cell niche. We demonstrate that the default fate of Lgr5+ ISCs is lineage commitment, escape from which requires both Rspo and Wnt ligands. However, gain-of-function studies using Rspo versus a novel non-lipidated Wnt analog reveal qualitatively distinct, non-interchangeable roles for these ligands in ISCs. Wnts are insufficient to induce Lgr5+ ISC self-renewal, but rather confer a basal competency by maintaining Rspo receptor expression that enables Rspo to actively drive and specify the extent of stem cell expansion. This functionally non-equivalent yet cooperative interplay between Wnt and Rspo ligands establishes a molecular precedent for regulation of mammalian stem cells by distinct priming and self-renewal factors, with broad implications for precision control of tissue regeneration

Progenitor identification and SARS-CoV-2 infection in human distal lung organoids

The distal lung contains terminal bronchioles and alveoli that facilitate gas exchange. Three-dimensional in vitro human distal lung culture systems would strongly facilitate investigation of pathologies including interstitial lung disease, cancer, and SARS-CoV-2-associated COVID-19 pneumonia. We generated long-term feeder-free, chemically defined culture of distal lung progenitors as organoids derived from single adult human alveolar epithelial type II (AT2) or KRT5+ basal cells. AT2 organoids exhibited AT1 transdifferentiation potential while basal cell organoids developed lumens lined by differentiated club and ciliated cells. Single cell analysis of basal organoid KRT5+ cells revealed a distinct ITGA6+ITGB4+ mitotic population whose proliferation further segregated to a TNFRSF12Ahi subfraction comprising ~10% of KRT5+ basal cells, residing in clusters within terminal bronchioles and exhibiting enriched clonogenic organoid growth activity. Distal lung organoids were created with apical-out polarity to display ACE2 on the exposed external surface, facilitating SARS-CoV-2 infection of AT2 and basal cultures and identifying club cells as a novel target population. This long-term, feeder-free organoid culture of human distal lung, coupled with single cell analysis, identifies unsuspected basal cell functional heterogeneity and establishes a facile in vitro organoid model for human distal lung infections including COVID-19-associated pneumonia

Testing the pIRIR on pottery and SG-OSL on clay sediment from the known age Xiongnu “Royal” tomb at Noin-Ula, Mongolia

Understanding the timing of the world's first nomadic empire Xiongnu is critical to understanding nomadic politics of the Eurasian past. This study presents a geochronological study conducted on a selection of archeological materials including clay sediment and three potteries from elite Xiongnu tomb at the Noin-Ula Mountains, Mongolia. In order to obtain an accurate OSL chronology, at least two different luminescence methods were applied for clay sediment (e.g., quartz single-grain OSL and pIRIR on the feldspar component of the polymineral fine grains) and for pottery samples (pIRIR to sand-sized K-feldspar and to polymineral fine grains). For the clay sediment, the quartz FMM age of 2160þinspace±þinspace160 a is consistent with independent age control for the site, revealing the time of mixing of clay sediment for construction, while the pIRIR on polymineral fine grains failed to date the timing of construction of the tomb. In contrast, for fired potteries, the pIRIR ages (for preheats between 180 to 270 °C) show a consistency with the existing chronology for the site. The study shows that the advantage of luminescence dating human activities in archeological contexts, e.g., construction of the tomb and firing the pottery, is achieved by the combination of luminescence results from different materials

LM-OSL from single grains of quartz: a preliminary study

The recently developed single grain attachment for the Riso TL-OSL reader has been modified to achieve linearly modulated optically stimulated luminescence (LM-OSL). Three different types of luminescence behaviour were observed in 81 quartz grains measured. These types are those showing only the easy-to-bleach component, those with only the hard-to-bleach component, and those exhibiting all components. The results of this preliminary study show that LM-OSL experiments carried out at the single grain level may give important insights into the luminescence properties observed when viewing samples consisting of multiple grains