Gas-liquid chromatography was applied in thermodynamic investigations of processes of complexation and enantioseparation by alpha- and [-cyclodextrins of chiral monoterpenoids. The distribution constants, stability constants and thermodynamic parameters enthalpy, entropy and free energy of the complexation processes were determined. It has been found that enantioseparation of monoterpenes by alpha- and beta-cyclodextrins is the result of formation of 1:2 stoichiometric complexes. When 1:1 stoichiometric complexes are formed, enantioselectivity is not observed. All investigated processes of complexation are enthalpy-driven regardless of the stoichiometry of the formed complexes. -deltaH, -TdeltaS and -deltaG of complexation process have higher values for bicyclic than for monocyclic monoterpenoids as well as for alpha-CD than for beta-CD. The first or second step of complexation may be responsible for enantioselectivity.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.chroma.2005.05.011 | DOI Listing |
Cell Rep
January 2025
School of Infection, Inflammation and Immunology, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK. Electronic address:
Interleukin (IL)-7 promotes T cell expansion during lymphopenia. We studied the metabolic basis in CD4 T cells, observing increased glucose usage for nucleotide synthesis and oxidation in the tricarboxylic acid (TCA) cycle. Unlike other TCA metabolites, glucose-derived citrate does not accumulate upon IL-7 exposure, indicating diversion into other processes.
View Article and Find Full Text PDFCell Mol Life Sci
January 2025
Department of Anesthesiology, Shenzhen Children's Hospital, Yitian Road 7019, Shenzhen, 518000, China.
Hair follicle (HF) development and pigmentation are complex processes governed by various signaling pathways, such as TGF-β and FGF signaling pathways. Nestin + (neural crest like) stem cells are also expressed in HF stem cells, particularly in the bulge and dermal papilla region. However, the specific role and differentiation potential of these Nestin-positive cells within the HF remain unclear, especially regarding their contribution to melanocyte formation and hair pigmentation.
View Article and Find Full Text PDFMol Biol Rep
January 2025
Mahatma Gandhi Medical Advanced Research Institute (MGMARI), Sri Balaji Vidyapeeth (Deemed to be University), Puducherry, 607402, India.
MicroRNAs (miRNAs) and transfer RNA-derived stress-induced RNAs (tiRNAs) have emerged as crucial players in the post-transcriptional regulation of gene expression in various cellular processes, including immunity and host defense against infections. In recent years, increasing evidence has highlighted their complex role in influencing the host response during viral and bacterial infections. miRNAs have been shown to play multiple roles in host-pathogen interaction like TLR activation and altered disease virulence during bacterial infections.
View Article and Find Full Text PDFPlanta
January 2025
Institute of Plant Genetics and Biotechnology, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Akademicka 2, P. O. Box 39A, 950 07, Nitra, Slovak Republic.
DbChitI-3, Drosera binata's acidic chitinase, peaks at pH 2.5 from 15 °C to 30 °C. Gene expression is stimulated by polysaccharides and suppressed by monosaccharide digestion, implying a feedback loop in its transcriptional regulation.
View Article and Find Full Text PDFJ Natl Cancer Inst
January 2025
Surveillance Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Rockville, MD, USA.
Childhood cancers are a heterogeneous group of rare diseases, accounting for less than 2% of all cancers diagnosed worldwide. Most countries, therefore, do not have enough cases to provide robust information on epidemiology, treatment, and late effects, especially for rarer types of cancer. Thus, only through a concerted effort to share data internationally will we be able to answer research questions that could not otherwise be answered.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!