نتایج جستجو برای: c21

تعداد نتایج: 717  

Journal: :Organic letters 2000
K E Drouet T Ling H V Tran E A Theodorakis

[structure: see text] Reveromycin A (1) belongs to a family of microbial polyketides with unusual structural features and biological activities. The structure of 1 is composed of a [6,6] spiroketal core decorated with highly unsaturated side chains. As a prelude to the synthesis of 1, we present herein a short, efficient, and enantioselective synthesis of the C9-C21 fragment 5 (spiroketal core)...

2014
Alexander Sohn Nadja Klein Thomas Kneib

In this paper we explore the application of Generalised Additive Models of Location, Scale and Shape for the analysis of conditional income distributions in Germany following the reunification. We find that conditional income distributions can generally be modelled using the three parameter Dagum distribution and our results hint at an even more pronounced effect of skill-biased technological c...

2005
T. D. Nguyen S. Lasaulce

A special case of the discrete memoryless cooperative broadcast channel, as defined by Dabora and Servetto, is investigated. The capacity region is provided in the case where the information messages are sent over a deterministic broadcast channel (Y1, Y2) = h(X) with a (C12, C21)-admissible conference link between the receivers. In this framework we also give the capacity in the single common ...

Journal: :Biochemical and biophysical research communications 1967
J S Youngner D S Feingold

The interferon response elicited by Salmonella typhimurium mutants in mice is not dependent on the presence of a complete cell wall lipopolysaccharide. In fact, a mutant (G30/C21) which has lost all the polysaccharide side chains and sugars of the O antigen and contains only 2-keto-3-deoxyoctonate and lipid is indistinguishable in its interferon-stimulating ability from the wild type which poss...

Journal: :Angewandte Chemie 2014
K C Nicolaou Lei Shi Min Lu Manas R Pattanayak Akshay A Shah Heraklidia A Ioannidou Manjunath Lamani

The total synthesis of cytotoxic polyketides myceliothermophins E (1), C (2), and D (3) through a cascade-based cyclization to form the trans-fused decalin system is described. The convergent synthesis delivered all three natural products through late-stage divergence and facilitated unambiguous C21 structural assignments for 2 and 3 through X-ray crystallographic analysis, which revealed an in...

Journal: :American Economic Journal: Microeconomics 2022

We show that the treatment effect estimated by standard methods such as regression discontinuity analysis or difference-in-differences may contain a transient “learning effect” is entangled with long-term of treatment. This learning occurs when variable interest agents’ efforts, and control correspond to success failure: failure gives agents information about how much their effort matters, cons...

Journal: :Current Biology 2010
Nadav Sorek Oshik Segev Orit Gutman Einat Bar Sandra Richter Limor Poraty Joel A. Hirsch Yoav I. Henis Efraim Lewinsohn Gerd Jürgens Shaul Yalovsky

Rho GTPases are master regulators of cell polarity. For their function, Rhos must associate with discrete plasma membrane domains. Rho of Plants (ROPs) or RACs comprise a single family. Prenylation and S-acylation of hypervariable domain cysteines of Ras and Rho GTPases are required for their function; however, lipid modifications in the G domain have never been reported. Reversible S-acylation...

2017
Yu Zhang Kaiqiang Li Youmin Ying Bingyu Chen Ke Hao Boxu Chen Yu Zheng Jianxin Lyu Xiangming Tong Xiaopan Chen Ying Wang Zhajun Zhan Wei Zhang Zhen Wang

Marsdenia tenacissimae extraction (MTE), a traditional herbal medicine, has exhibited anti-tumor effects on a variety of cancers. However, its effectiveness and the mechanism of action in Hepatocellular carcinoma (HCC) has not been fully understood. In the present study, we demonstrate that C21 steroid-enriched fraction from MTE, which contains five main C21 steroids (FR5) exhibits obvious phar...

2013
LIANG-FEI YE YI-QI WANG BO YANG RU-SONG ZHANG

The present study aimed to investigate the anti-cancer effect of a C21-steroidal glycoside (CG) isolated from the roots of Cynanchum auriculatum. CG was able to inhibit the growth of human cancer cells (SGC-7901 cells) in a concentration and time-dependent manner in vitro. SGC-7901 cells exposed to CG (10.8 and 21.6 μM) exhibited typical morphological apoptosis characteristics, such as nuclear-...

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