It was shown that 100mug quantities of 4,4'-dimethyl[2-(3)H(2)]cholesta-8,14-dien-3beta-ol (IIIa), tritiated cholesta-8,14-dien-3beta-ol, 4,4'-dimethyl[2-(3)H(2)]cholesta-7,14-dien-3beta-ol, dihydro[2-(3)H(2)]lanosterol and [24-(3)H]lanosterol were converted by a 10000g supernatant of rat liver homogenate into cholesterol in 17%, 54%, 6%, 9.5% and 24% yields respectively. From an incubation of dihydro[3alpha-(3)H]lanosterol with a rat liver homogenate in the presence of a trap up to 38% of the radioactivity was found to be associated with a fraction that was unambiguously shown to be 4,4'-dimethylcholesta-8,14-dien-3beta-ol. Another related compound, 4,4'-dimethylcholesta-7,14-dien-3beta-ol was also shown to be equally effective in its ability to trap compound (IIIa) from an incubation of dihydro[3alpha-(3)H]lanosterol. The mechanism of the further conversion of the compound (IIIa) into cholesterol occurred by the reduction of the 14,15-double bond and involved the addition of a hydrogen atom from the medium to C-15 and another from the 4-position of NADPH to C-14. Two possible mechanisms for the removal of the 14alpha-methyl group in sterol biosynthesis are discussed.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1176495 | PMC |
| http://dx.doi.org/10.1042/bj1210131 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Peptide nucleic acid (PNA) clamps reduce amplification of host chloroplast and mitochondria rRNA gene sequences and increase detected diversity in 16S rRNA gene profiling analysis of oak-associated microbiota.
Environ Microbiome
January 2025
School of Natural Sciences, Bangor University, Bangor, UK.
Background: Acquiring representative bacterial 16S rRNA gene community profiles in plant microbiome studies can be challenging due to the excessive co-amplification of host chloroplast and mitochondrial rRNA gene sequences that reduce counts of plant-associated bacterial sequences. Peptide Nucleic Acid (PNA) clamps prevent this by blocking PCR primer binding or binding within the amplified region of non-target DNA to stop the function of DNA polymerase. Here, we applied a universal chloroplast (p)PNA clamp and a newly designed mitochondria (m)PNA clamp to minimise host chloroplast and mitochondria amplification in 16S rRNA gene amplicon profiles of leaf, bark and root tissue of two oak species (Quercus robur and Q.
View Article and Find Full Text PDFAssessment of nurses' knowledge and practice of pressure injuries prevention for critically ill patients in Rwanda: a cross-sectional study.
BMC Nurs
January 2025
College of Medicine and Health Sciences, School of Nursing and Midwifery, University of Rwanda, Po. Box: 3286, Kigali, Rwanda.
Background: Pressure injuries are costly and can lead to mortality and psychosocial consequences if not managed effectively. Proper management of pressure injuries is crucial for quality nursing care. However, there is limited research on nurses' knowledge and practices in preventing and managing pressure injuries among critically ill patients in Rwanda.
View Article and Find Full Text PDFSelf-administered active versus sham acupressure for diarrhea predominant irritable bowel syndrome: a nurse-led randomized clinical trial.
BMC Nurs
January 2025
Medical Surgical Nursing Department, Faculty of Nursing, Alexandria University, Alexandria, Egypt.
Background: Diarrhea-predominant irritable bowel syndrome (IBS-D) significantly impacts patients' quality of life, with existing treatments offering limited relief. Self-administered acupressure presents a potential non-invasive, cost-effective treatment option that could alleviate symptoms and enhance health outcomes in these patients.
Aim: This randomized controlled trial aimed to evaluate the effect of active acupressure compared to sham acupressure on primary and secondary outcomes among IBS-D patients.
Association between metabolic score for visceral fat index and BMI-adjusted skeletal muscle mass index in American adults.
Lipids Health Dis
January 2025
Department of Orthopedics, The 921st Hospital of the People's Liberation Army, The Second Affiliated Hospital of Hunan Normal University, Changsha, 410003, People's Republic of China.
Background: The metabolic score for visceral fat (METS-VF) is a recently identified index for evaluating visceral fat, also referred to as abdominal obesity. The skeletal muscle mass index (SMI) serves as a critical measure for assessing muscle mass and sarcopenia. Both obesity and the reduction of muscle mass can significantly affect human health.
View Article and Find Full Text PDFBiphasic lipid extraction from microalgae after PEF-treatment reduces the energy demand of the downstream process.
Biotechnol Biofuels Bioprod
January 2025
Institute for Pulsed Power and Microwave Technology (IHM), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany.
Background: The gradual extrusion of water-soluble intracellular components (such as proteins) from microalgae after pulsed electric field (PEF) treatment is a well-documented phenomenon. This could be utilized in biorefinery applications with lipid extraction taking place after such an 'incubation' period, i.e.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!