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Secondary Metabolites from Clerodendrum Infortunatum L.: Their Bioactivities and Health Benefits
Published in Hafiz Ansar Rasul Suleria, Megh R. Goyal, Health Benefits of Secondary Phytocompounds from Plant and Marine Sources, 2021
R. L. Helen, K. Jayesh, S. Syama, M. S. Latha
Terpenes are a diverse group containing one or more five-carbon isoprene units. They are synthesized from common precursor isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) via two independent pathways: the cytosolic mevalonic acid (MVA) pathway and the plastid localized methylerythritol phosphate (MEP) pathway [89]. According to the isoprene units present, terpenoids are categorized into: hemiterpenes (C5), monoterpenes (C10), sesquiterpenes (C15), diterpenes (C20), triterpenes (C30), etc. Terpenoids function as plant and animal hormones, membrane lipids, insect attractants, antifeedants, mediators of the electron transport system, and play a major role in the plant-environment interaction [35].
Implication of Mitochondrial Coenzyme Q10 (Ubiquinone) in Alzheimer’s Disease *
Published in Abhai Kumar, Debasis Bagchi, Antioxidants and Functional Foods for Neurodegenerative Disorders, 2021
Sayantan Maitra, Dibyendu Dutta
The precursor of the quinone ring is only 4-hydroxybenzoic acid (4-HB), which is derived from tyrosine. Mevalonate pathway is the main route to synthesize the isoprenoid tail, which is also common to cholesterol biosynthesis. The initial part of the mevalonate pathway involves the condensation of three acetyl-CoA to form 3-hydroxy-3-methylglutaryl-CoA by HMG-CoA reductase, which is the main regulatory enzyme in cholesterol biosynthesis. Mevalonate is subsequently phosphorylated in two steps by mevalonate kinase (MVK) and phosphomevalonate kinase (PMVK). Then, decarboxylation of mevalonate pyrophosphate yields isopentenyl pyrophosphate (IPP), which is the precursor of farnesyl pyrophosphate (FPP) and the building block for the biosynthesis of dolichol and the side chain of CoQ. Isomerization of IPP gives dimethylallyl pyrophosphate (DMAPP), and FPP synthase utilizes IPP and DMAPP to make FPP with the intermediary formation of geranyl pyrophosphate (GPP). FPP is further converted into cholesterol, dolichols, and CoQ [6]. Decalyprenyl diphosphate synthase (DPS) is a heterotetramer consisting of two different proteins, namely, PDSS1 and PDSS2. DPS catalyzes the condensation of IPP and FPP to produce ten units of prenyldiphosphate (decaprenyl diphosphate). 4-Hydroxybenzoic acid-decaprenyl diphosphate transferase (encoded by CoQ2 gene in humans) catalyzes the condensation of PHB with the isoprenoid tail to yield CoQ10 [7,8].
Anti-Cancer Agents from Natural Sources
Published in Rohit Dutt, Anil K. Sharma, Raj K. Keservani, Vandana Garg, Promising Drug Molecules of Natural Origin, 2020
Debasish Bandyopadhyay, Felipe Gonzalez
Terpenoids are a large class of natural compounds composed of two or more isoprene (2-methyl-1,3-butadiene, C5H8)units. The isoprene units built the carbon skeletal of terpenes. Terpenoids contain a general formula (C5H8)n and termed as monoterpenoids (C10), sesquiterpenoids (C15), diterpenoids (C20), sesterterpenoids (C25), triterpenoids (C30), sesquiterpenoids (C35), tetraterpenoids(C40) and polyterpenoids (>C40) (Figure 5.21). Terpenes are secondary metabolites, which are basically synthesized from isopentyl pyrophosphate and dimethylallyl pyrophosphate catalized by the enzyme terpene synthase. Terpenoids alone consist of over 50,000 compounds, making them a rich reservoir for new pharmacologically favored molecules.
TRPV4 antagonists: a patent review (2015–2020)
Published in Expert Opinion on Therapeutic Patents, 2021
Brian G. Lawhorn, Edward J. Brnardic, David J. Behm
TRPV4 channels are ubiquitously expressed and activated by a broad range of stimuli including hypotonicity, temperature, stretch, pH, UVB radiation, arachidonic acid metabolites such as 5,6-epoxyeicosatrienoic acid, dimethylallyl pyrophosphate, and phorbol derivatives such as 4α-phorbol 12,13-didecanoate (4α-PDD) [10]. To date, 38 proteins have been identified to interact with TRPV4 [11] and several have been shown to modulate localization and signaling. In addition, TRPV4 activity can be post-translationally enhanced via PKA- and PKC-dependent phosphorylation [12–14].