Two clerodane diterpenes isolated from Polyalthia longifolia leaves: comparative structural features, anti-histaminic and anti-Helicobacter pylori activities

2020 ◽  
pp. 1-5
Author(s):  
Martina P. Edmond ◽  
Nada M. Mostafa ◽  
Mohamed El-Shazly ◽  
Abdel Nasser B. Singab
mSphere ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Emily G. Sweeney ◽  
Andrew Nishida ◽  
Alexandra Weston ◽  
Maria S. Bañuelos ◽  
Kristin Potter ◽  
...  

ABSTRACTBacteria are often found living in aggregated multicellular communities known as biofilms. Biofilms are three-dimensional structures that confer distinct physical and biological properties to the collective of cells living within them. We used agent-based modeling to explore whether local cellular interactions were sufficient to give rise to global structural features of biofilms. Specifically, we asked whether chemorepulsion from a self-produced quorum-sensing molecule, autoinducer-2 (AI-2), was sufficient to recapitulate biofilm growth and cellular organization observed for biofilms ofHelicobacter pylori, a common bacterial resident of human stomachs. To carry out this modeling, we modified an existing platform, Individual-based Dynamics of Microbial Communities Simulator (iDynoMiCS), to incorporate three-dimensional chemotaxis, planktonic cells that could join or leave the biofilm structure, and cellular production of AI-2. We simulated biofilm growth of previously characterizedH. pyloristrains with various AI-2 production and sensing capacities. Using biologically plausible parameters, we were able to recapitulate both the variation in biofilm mass and cellular distributions observed with these strains. Specifically, the strains that were competent to chemotax away from AI-2 produced smaller and more heterogeneously spaced biofilms, whereas the AI-2 chemotaxis-defective strains produced larger and more homogeneously spaced biofilms. The model also provided new insights into the cellular demographics contributing to the biofilm patterning of each strain. Our analysis supports the idea that cellular interactions at small spatial and temporal scales are sufficient to give rise to larger-scale emergent properties of biofilms.IMPORTANCEMost bacteria exist in aggregated, three-dimensional structures called biofilms. Although biofilms play important ecological roles in natural and engineered settings, they can also pose societal problems, for example, when they grow in plumbing systems or on medical implants. Understanding the processes that promote the growth and disassembly of biofilms could lead to better strategies to manage these structures. We had previously shown thatHelicobacter pyloribacteria are repulsed by high concentrations of a self-produced molecule, AI-2, and thatH. pylorimutants deficient in AI-2 sensing form larger and more homogeneously spaced biofilms. Here, we used computer simulations of biofilm formation to show that localH. pyloribehavior of repulsion from high AI-2 could explain the overall architecture ofH. pyloribiofilms. Our findings demonstrate that it is possible to change global biofilm organization by manipulating local cell behaviors, which suggests that simple strategies targeting cells at local scales could be useful for controlling biofilms in industrial and medical settings.


Molecules ◽  
2014 ◽  
Vol 19 (2) ◽  
pp. 2049-2060 ◽  
Author(s):  
Tung-Ho Wu ◽  
Yung-Yi Cheng ◽  
Chao-Jung Chen ◽  
Lean-Teik Ng ◽  
Li-Chen Chou ◽  
...  

1998 ◽  
Vol 180 (2) ◽  
pp. 426-429 ◽  
Author(s):  
Elaine Allan ◽  
Peter Mullany ◽  
Soad Tabaqchali

ABSTRACT Antiserum raised against whole Helicobacter pyloricells identified a novel 94-kDa antigen. The nucleotide sequence of the gene encoding the 94-kDa antigen was determined, and analysis of the deduced amino acid sequence revealed structural features typical of the ClpB ATPase family of stress response proteins. An isogenic H. pylori clpB mutant showed increased sensitivity to high-temperature stress, indicating that the clpB gene product functions as a stress response protein in H. pylori.


2009 ◽  
Vol 4 (3) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Koneni V. Sashidhara ◽  
Suriya P. Singh ◽  
P.K. Shukla

Phytochemical investigation of the ethanolic extract of leaves of Polyalthia longifolia var. pendula has led to the isolation of seven clerodane diterpenoids and five alkaloids. (-)-14, 15-bisnor-3, 11 E-kolavadien-13-one (1), (-)-16-oxocleroda-3,13(14) E-dien-15-oic acid (2), (-)-16α-hydroxycleroda-3,13 (14) Z-dien-15,16-olide (3), (+)-(4→2)-abeo-16(R/S)-2, 13 Z-kolavadien-15, 16-olide-3-al (4), (-)-3β, 16α-dihydroxycleroda-4(18), 13(14) Z-dien45,16-olide (5), (-)-3, 12 E-kolavadien-15-oic acid-16-al (6), (-)-labd-13 E-en-8-ol-15-oic acid (7), liriodenine (8), (-)-anonaine (9), (+)-isoboldine (10), (-)-asimilobine (11) and hordenine (12) have been isolated. This is the first report of 1, 6 and 10 from this plant species while 12 is reported for first time from this genus. Clerodane derivatives 1-7 were evaluated for their antimicrobial activity. Diterpene 3 was found to be most potent agent with MIC value of 6.25 μg/mL against Staphylococcus aureus and Sporothrix schenckii.


2013 ◽  
Vol 62 (10) ◽  
pp. 843-848 ◽  
Author(s):  
Dina Permata Sari ◽  
Masayuki Ninomiya ◽  
Mai Efdi ◽  
Adlis Santoni ◽  
Sanusi Ibrahim ◽  
...  

2018 ◽  
Author(s):  
Emily G. Sweeney ◽  
Andrew Nishida ◽  
Alexandra Weston ◽  
Maria S. Bañuelos ◽  
Kristin Potter ◽  
...  

AbstractMature bacterial biofilms have elaborate three-dimensional architectures that endow these structures with their durability and resistance to environmental perturbations. We used agent-based modeling to explore whether local cellular interactions were sufficient to give rise to global structural features of biofilms. Specifically, we asked whether chemorepulsion from a self-produced quorum-sensing molecule, autoinducer-2 (AI-2), was sufficient to recapitulate biofilm growth and cellular organization observed for biofilms of the human pathogen Helicobacter pylori. To carry out this modeling, we modified an existing platform, Individual-based Dynamics of Microbial Communities Simulator (iDynoMiCS), to incorporate three-dimensional chemotaxis, planktonic cells that could join or leave the biofilm structure, and cellular production of AI-2. We simulated biofilm growth of previously characterized H. pylori strains with varying AI-2 production and sensing capacities. Using biologically plausible parameters, we were able to recapitulate both the variation in biofilm mass and cellular distributions observed with these strains. Specifically, the strains that were competent to chemotax away from AI-2 produced smaller and more heterogeneously spaced biofilms, whereas the AI-2 chemotaxis defective strains produced larger and more homogeneously spaced biofilms. The model also provided new insights into the cellular demographics contributing to the biofilm patterning of each strain. Our analysis supports the idea that cellular interactions at small spatial and temporal scales are sufficient to give rise to larger scale emergent properties of biofilms.ImportanceMost bacteria exist in aggregated, three-dimensional structures called biofilms. Biofilms are resistant to antimicrobials and can pose societal problems, for example when they grow in plumbing systems or on medical implants. Understanding the processes that promote the growth and disassembly of biofilms could lead to better strategies to manage these structures. We had previously shown that Helicobacter pylori bacteria are repulsed by high concentrations of a self-produced molecule, autoinducer-2 (AI-2) and that H. pylori mutants deficient in AI-2 sensing form larger and more homogeneously spaced biofilms. Here we used computer simulations of biofilm formation to show that local H. pylori behavior of repulsion from high AI-2 could explain the overall architecture of H. pylori biofilms. Our findings demonstrate that it is possible to change global biofilm organization by manipulating local cell behaviors, which suggests that simple strategies targeting cells at local scales could be useful for controlling biofilms in industrial and medical settings.


Author(s):  
RAKESH PAHWA ◽  
BIGUL YOGESHVER BHARDWAJ ◽  
ARCHANA SHARMA ◽  
MONA PIPLANI ◽  
MANISH KUMAR

Helicobacter pylori is a virulent human pathogen infecting about 50% of the population worldwide. Being a leading cause of gastric ulcer, duodenal ulcer, gastritis, dyspepsia, gastric tumorigenesis etc., this organism has been the focus of concerted study to establish uncertainty of its genetics, immunopathogenesis and cell biology. Scientists have tried to effectively eradicate this pathogen from the gastrointestinal tract in various manners. Inquest of this venture, gastroretentive drug delivery systems including floating dosage forms have emerged as a boon and offer significantly improved therapeutic effects of different antimicrobial drugs. This article presents an evocative review of the structural features, epidemiological evidences and various pharmacotherapeutics vistas. In addition, various novel gastroretentive dosage forms developed so far to combat Helicobacter pylori infection are also discussed. Comprehensive literature review has been performed for this manuscript by utilizing relevant databases like PubMed, SCOPUS, Web of Science, Science Direct, Google Scholar etc., from 1997 up to the year 2020.


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