نتایج جستجو برای: pentacyclic graphs

تعداد نتایج: 98241  

Journal: :Zeitschrift fur Naturforschung. C, Journal of biosciences 2005
Rubén García Cesia Cayunao Ronny Bocic Nadine Backhouse Carle Delporte Mercedes Zaldivar Silvia Erazo

Bioassay-directed fractionation for the determination of antimicrobial activity of Uncaria tomentosa, has led to the isolation of isopteropodine (0.3%), a known Uncaria pentacyclic oxindol alkaloid that exhibited antibacterial activity against Gram positive bacteria.

Journal: :bulletin of the iranian mathematical society 2015
i. ahmad p. m. higgins

bandwidth labelling is a well known research area in graph theory. we provide a new proof that the bandwidth of mobius ladder is 4, if it is not a $k_{4}$, and investigate the bandwidth of a wider class of mobius graphs of even strips.

پایان نامه :دانشگاه تربیت معلم - سبزوار - دانشکده ریاضی و کامپیوتر 1390

همچنین با استفاده از نتیجه های به دست آمده الگوریتم هایی برای امتحان یکتایی رنگ پذیری ارائه داده شد. به عنوان یک کاربرد، مثال نقضی را برای حدس ژو، مربوط به ‎3-‎رنگ پذیری یکتای گراف های بدون مثلث بررسی می کنیم ‎ایده ی اصلی این پایان نامه از مقاله ‎‎c‎. ‎hillar‎, ‎t‎. ‎windfeldt‎, ‎it algebraic characterization of uniquely vertex colorable graphs, ‎j‎. ‎combin‎. ‎theory ser‎. ‎b 98 (2008) 400...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1996
C H Heathcock

The Daphniphyllum alkaloids are a group of highly complex polycyclic alkaloids. Examination of the structures if several members of this family of natural products led to a hypothesis about their mode of biosynthesis (depicted in Scheme I). Based on this hypothetical biosynthetic pathway, a laboratory synthesis was designed that incorporated as a key transformation the novel one-pot transformat...

Journal: :Molecules 2016
Jinjie Li Bo Zhang Hailing Liu Xuan Zhang Xiaoya Shang Changqi Zhao

One new pentacyclic triterpenoid, 3β-carboxylicfilic-4(23)-ene (1), and three known pentacyclic triterpenoids, adian-5-en-3α-ol (2), fernenol (3), and fern-7-en-3β-ol (4) were isolated from the petroleum ether phase of the ethanolic extract of Ainsliaea yunnanensis Franch. Their structures were established by spectroscopic methods including 1-D and 2-D NMR, and MS experiments. Compounds 1, 2, 3...

Journal: :Molecules 2017
Shao-Rong Wang Tingting Xu Kai Deng Chi-Wai Wong Jinsong Liu Wei-Shuo Fang

The pentacyclic triterpene oleanolic acid (OA, 1) with known farnesoid X receptor (FXR) modulatory activity was modified at its C-3 position to find new FXR-interacting agents. A diverse substitution library of OA derivatives was constructed in silico through a 2D fingerprint similarity cluster strategy. With further docking analysis, four top-scored OA 3-O-ester derivatives were selected for s...

2018
Farid Khallouki Robert Wyn Owen Sandrine Silvente-Poirot Marc Poirot

Bryonolic acid (BrA) is a pentacyclic triterpene present in several plants used in African traditional medicine such as Anisophyllea dichostyla R. Br. Here we investigated the in vitro anticancer properties of BrA. We report that BrA inhibits acyl-coA: cholesterol acyl transferase (ACAT) activity in rat liver microsomes in a concentration-dependent manner, blocking the biosynthesis of the chole...

Journal: :Natural product letters 2001
N Jahan A Malik G Mustafa Z Ahmad S Ahmad E Anis S Malik S Shujaat N Afza Atta-Ur-Rahman

Pentacyclic triterpenes (1) and (2) have been isolated from Mimusops elengi and assigned structures 3beta,6beta,19alpha,23-tetrahydroxy-urs-12-ene and 1beta-hydroxy-3beta-hexanoyllup-20 (29)-ene-23, 28-dioic acid, respectively, on the basis of spectroscopic studies including 2D-NMR. The compound 1 showed moderate inhibiting activity against beta-glucuronidase enzyme

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت دبیر شهید رجایی - پژوهشکده علوم 1393

در این پایان نامه دو مقاله زیر بررسی شده اند، که اولی در مورد رنگ آمیزی موقعیت یاب و عدد رنگی موقعیت یاب گراف ها است و دیگری همه ی درخت های با عدد رنگی موقعیت یابی 3 را مشخص می کند. همچنین در این پایان نامه عدد رنگی موقعیت یاب گراف های مسیر، دور، کامل، دوبخشی، ستاره ها، درخت های دو ستاره و کاترپیلارها را مشخص می کند.

Journal: :journal of linear and topological algebra (jlta) 0
f ramezani department of basic science , imam khomeini international university, qazvin, iran. e vatandoost department of basic science , imam khomeini international university, qazvin, iran.

‎‎let r be a non-commutative ring with unity‎. ‎the commuting graph‎ ‎of $r$ denoted by $gamma(r)$‎, ‎is a graph with a vertex set‎ ‎$rsetminus z(r)$ and two vertices $a$ and $b$ are adjacent if and only if‎ ‎$ab=ba$‎. ‎in this paper‎, ‎we investigate non-commutative rings with unity of order $p^n$ where $p$ is prime and $n in lbrace 4,5 rbrace$‎. it is shown that‎, ‎$gamma(r)$ is the disjoint ...

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