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Des-N-Methylnoracronycine from the roots of Carissa conjesta. Wight
Ganapaty S,Ch. Bharath,Laatsch H
International Journal of Green Pharmacy , 2010,
Abstract: The methanolic extract of the roots of Carissa conjesta on a sequence of chromatographic techniques afforded a des-N-methylnoracronycine, an acridone alkaloid, carissone, carindone, lupeol besides stigmasterol, ursolic acid and its methyl ester. This is the first report of isolation of an alkaloid from the roots of C. conjesta and also from Carissa genus. All the isolated compounds were characterised by spectroscopic methods.
Pachydictyols B and C: New Diterpenes from Dictyota dichotoma Hudson
Ghada S. E. Abou-El-Wafa,Mohamed Shaaban,Khaled A. Shaaban,Mohamed E. E. El-Naggar,Armin Maier,Heinz H. Fiebig,Hartmut Laatsch
Marine Drugs , 2013, DOI: 10.3390/md11093109
Abstract: Two new diterpenoids, pachydictyol B ( 1a/ 1b) and C ( 2), were isolated from the dichloromethane extract of the marine brown alga, Dictyota dichotoma, collected from the Red Sea coast of Egypt, along with the known metabolites, pachydictyol A ( 3a), dictyol E ( 4), cis-africanan-1α-ol ( 5a), fucosterol ( 6), tetrahydrothiophen-1,1-dioxide and poly-β-hydroxybutyric acid. GC-MS analysis of the nonpolar fractions also indicated the presence of β-bourbonene and nonanal, along with three hydrocarbons and five fatty acids or their simple derivatives, respectively. GC-MS analysis of the unsaponifiable algal petroleum ether extract revealed the presence of a further eight compounds, among them 2,2,6,7-tetramethyl-10-oxatricyclo[4.3.0.1(1,7)]decan-5-one ( 7), N-(4-bromo- n-butyl)-pipe ridin-2-one ( 8) and tert-hexadecanethiol. Structures 1– 6 were assigned by 1D and 2D NMR, mass spectra (EI, CI, HREI and HRESI) and by comparison with data from related structures. The crude algal extract was potently active against the breast carcinoma tumor cell line, MCF7 (IC 50 = 0.6 μg mL ?1); pachydictyol B ( 1a) and dictyol E ( 4) showed weak antimicrobial properties, and the other compounds were inactive. Pachydictyols B ( 1a) and C ( 2) demonstrated a weak and unselective cytotoxicity against twelve human tumor cell lines with a mean IC 50 of >30.0 μM.
Human hair shaft proteomic profiling: individual differences, site specificity and cuticle analysis
Chelsea N. Laatsch,Blythe P. Durbin-Johnson,David M. Rocke,Sophie Mukwana,Abby B. Newland,Michael J. Flagler,Michael G. Davis,Richard A. Eigenheer,Brett S. Phinney,Robert H. Rice
PeerJ , 2015, DOI: 10.7717/peerj.506
Abstract: Hair from different individuals can be distinguished by physical properties. Although some data exist on other species, examination of the individual molecular differences within the human hair shaft has not been thoroughly investigated. Shotgun proteomic analysis revealed considerable variation in profile among samples from Caucasian, African–American, Kenyan and Korean subjects. Within these ethnic groups, prominent keratin proteins served to distinguish individual profiles. Differences between ethnic groups, less marked, relied to a large extent on levels of keratin associated proteins. In samples from Caucasian subjects, hair shafts from axillary, beard, pubic and scalp regions exhibited distinguishable profiles, with the last being most different from the others. Finally, the profile of isolated hair cuticle cells was distinguished from that of total hair shaft by levels of more than 20 proteins, the majority of which were prominent keratins. The cuticle also exhibited relatively high levels of epidermal transglutaminase (TGM3), accounting for its observed low degree of protein extraction by denaturants. In addition to providing insight into hair structure, present findings may lead to improvements in differentiating hair from various ethnic origins and offer an approach to extending use of hair in crime scene evidence for distinguishing among individuals.
Low Density Lipoprotein Receptor-Related Protein 1 Dependent Endosomal Trapping and Recycling of Apolipoprotein E
Alexander Laatsch, Malamatenia Panteli, Marijke Sornsakrin, Britta Hoffzimmer, Thomas Grewal, Joerg Heeren
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0029385
Abstract: Background Lipoprotein receptors from the low density lipoprotein (LDL) receptor family are multifunctional membrane proteins which can efficiently mediate endocytosis and thereby facilitate lipoprotein clearance from the plasma. The biggest member of this family, the LDL receptor-related protein 1 (LRP1), facilitates the hepatic uptake of triglyceride-rich lipoproteins (TRL) via interaction with apolipoprotein E (apoE). In contrast to the classical LDL degradation pathway, TRL disintegrate in peripheral endosomes, and core lipids and apoB are targeted along the endocytic pathway for lysosomal degradation. Notably, TRL-derived apoE remains within recycling endosomes and is then mobilized by high density lipoproteins (HDL) for re-secretion. The aim of this study is to investigate the involvement of LRP1 in the regulation of apoE recycling. Principal Findings Immunofluorescence studies indicate the LRP1-dependent trapping of apoE in EEA1-positive endosomes in human hepatoma cells. This processing is distinct from other LRP1 ligands such as RAP which is efficiently targeted to lysosomal compartments. Upon stimulation of HDL-induced recycling, apoE is released from LRP1-positive endosomes but is targeted to another, distinct population of early endosomes that contain HDL, but not LRP1. For subsequent analysis of the recycling capacity, we expressed the full-length human LRP1 and used an RNA interference approach to manipulate the expression levels of LRP1. In support of LRP1 determining the intracellular fate of apoE, overexpression of LRP1 significantly stimulated HDL-induced apoE recycling. Vice versa LRP1 knockdown in HEK293 cells and primary hepatocytes strongly reduced the efficiency of HDL to stimulate apoE secretion. Conclusion We conclude that LRP1 enables apoE to accumulate in an early endosomal recycling compartment that serves as a pool for the intracellular formation and subsequent re-secretion of apoE-enriched HDL particles.
Kiamycin, a Unique Cytotoxic Angucyclinone Derivative from a Marine Streptomyces sp.
Zeping Xie,Bing Liu,Hongpeng Wang,Shengxiang Yang,Hongyu Zhang,Yipeng Wang,Naiyun Ji,Song Qin,Hartmut Laatsch
Marine Drugs , 2012, DOI: 10.3390/md10030551
Abstract: Kiamycin ( 1), a new angucyclinone derivative possessing an 1,12-epoxybenz[a]anthracene ring system, was isolated from the marine Streptomyces sp. strain M268 along with the known compounds 8- O-methyltetrangomycin ( 3) and 8- O-methylrabelomycin ( 4). Their structures were elucidated by detailed spectroscopic analysis and comparison with literature data. The new angucyclinone derivative showed inhibitory activities against the human cell lines HL-60 (leukemia), A549 (lung adenocarcinoma), and BEL-7402 (hepatoma) with inhibition rates of 68.2%, 55.9%, and 31.7%, respectively, at 100 μM. It appears to have potential as an anticancer agent with selective activity.
Bioassay-Guided Isolation and Identification of Cytotoxic Compounds from Gymnosperma glutinosum Leaves
Ramiro Quintanilla-Licea,Rolando Morado-Castillo,Ricardo Gomez-Flores,Hartmut Laatsch,María Julia Verde-Star,Humberto Hernández-Martínez,Patricia Tamez-Guerra,Reyes Tamez-Guerra,Cristina Rodríguez-Padilla
Molecules , 2012, DOI: 10.3390/molecules170911229
Abstract: Bioassay-guided fractionation of hexane extracts of Gymnosperma glutinosum (Asteraceae) leaves, collected in North Mexico, afforded the known compounds hentriacontane (1) and (+)-13S,14R,15-trihydroxy-ent-labd-7-ene (2), as well as the new ent-labdane diterpene (?)-13S,14R,15-trihydroxy-7-oxo-ent-labd-8(9)-ene (3). In addition, D-glycero-D-galactoheptitol (4) was isolated from the methanolic extract of this plant. Their structures were established on the basis of high-field 1D- and 2D NMR methods supported by HR-MS data. The cytotoxic activity was determined by using the in vitro L5178Y-R lymphoma murine model. Hentriacontane (1) and the new ent-labdane 3 showed weak cytotoxicity, whereas the ent-labdane 2 showed significant (p < 0.05) and concentration dependent cytotoxicity (up to 78%) against L5178Y-R cells at concentrations ranging from 7.8 to 250 μg/mL.
Euler-Lagrange Elasticity: Differential Equations for Elasticity without Stress or Strain  [PDF]
H. H. Hardy
Journal of Applied Mathematics and Physics (JAMP) , 2013, DOI: 10.4236/jamp.2013.17004
Abstract:

Differential equations to describe elasticity are derived without the use of stress or strain. The points within the body are the independent parameters instead of strain and surface forces replace stress tensors. These differential equations are a continuous analytical model that can then be solved using any of the standard techniques of differential equations. Although the equations do not require the definition stress or strain, these quantities can be calculated as dependent parameters. This approach to elasticity is simple, which avoids the need for multiple definitions of stress and strain, and provides a simple experimental procedure to find scalar representations of material properties in terms of the energy of deformation. The derived differential equations describe both infinitesimal and finite deformations.

Euler-Lagrange Elasticity with Dynamics  [PDF]
H. H. Hardy
Journal of Applied Mathematics and Physics (JAMP) , 2014, DOI: 10.4236/jamp.2014.213138
Abstract: The equations of Euler-Lagrange elasticity describe elastic deformations without reference to stress or strain. These equations as previously published are applicable only to quasi-static deformations. This paper extends these equations to include time dependent deformations. To accomplish this, an appropriate Lagrangian is defined and an extrema of the integral of this Lagrangian over the original material volume and time is found. The result is a set of Euler equations for the dynamics of elastic materials without stress or strain, which are appropriate for both finite and infinitesimal deformations of both isotropic and anisotropic materials. Finally, the resulting equations are shown to be no more than Newton's Laws applied to each infinitesimal volume of the material.
Linear Algebra Provides a Basis for Elasticity without Stress or Strain  [PDF]
H. H. Hardy
Soft (Soft) , 2015, DOI: 10.4236/soft.2015.43003
Abstract: Linear algebra provides insights into the description of elasticity without stress or strain. Classical descriptions of elasticity usually begin with defining stress and strain and the constitutive equations of the material that relate these to each other. Elasticity without stress or strain begins with the positions of the points and the energy of deformation. The energy of deformation as a function of the positions of the points within the material provides the material properties for the model. A discrete or continuous model of the deformation can be constructed by minimizing the total energy of deformation. As presented, this approach is limited to hyper-elastic materials, but is appropriate for infinitesimal and finite deformations, isotropic and anisotropic materials, as well as quasi-static and dynamic responses.
Spectral resolution in hyperbolic orbifolds, quantum chaos, and cosmology
H. Then
Physics , 2007,
Abstract: We present a few subjects from physics that have one in common: the spectral resolution of the Laplacian.
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