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Chalcone (1,3-Diphenyl-2-Propene-1-One) Scaffold Bearing Natural Compounds as Nitric Oxide Inhibitors: Promising Antiedema Agents
Published in Debarshi Kar Mahapatra, Cristóbal Noé Aguilar, A. K. Haghi, Applied Pharmaceutical Practice and Nutraceuticals, 2021
Debarshi Kar Mahapatra, Sanjay Kumar Bharti, Vivek Asati
Active prenyl group containing chalcone isolated from Broussonetia papyrifera Vent is well known as Brussochalcone A (2) has been found to effectually reduce the production of NO in a concentration-dependent manner in LPS-activated macrophages (IC50 = 11.3 μM) by suppressing the activation of NF-κB as well as iNOS expression.34
Posttranslational Processing of ras and ras-Related Proteins
Published in Juan Carlos Lacal, Frank McCormick, The ras Superfamily of GTPases, 2017
John F. Hancock, Christopher J. Marshall
The polybasic domain of p21K-ras(B) contains six consecutive lysine residues (aal75-180; see Figure 1) and like the sites for palmitoylation in p21H-ras and p21N-ras, is found close to the CAAX motif. Some degree of plasma membrane localization is maintained when four of the six lysines of p21K-ras(B) are replaced with uncharged glutamine, however, replacing five or six lysines leads to a cytosolic localization.51 The six lysines in the polybasic domain can be replaced with six arginines without compromising plasma membrane localization or biological activity as measured by the transforming activity of oncogenic p21K-ras(B).60 This result suggests that me function of the polybasic domain is to give a net positive charge rather than to provide a specific amino acid sequence. Although the polybasic domain of p21K-ras(B) functions like palmitoylation of p21H-ras and p21N-ras to provide a second signal for plasma membrane localization, its consequences may be qualitatively different since p21K-ras(B) is readily removed from the plasma membrane by low concentration salt washes.51 Interestingly modifying the CAAX motif of p21K-ras(B) so that it is geranylgeranylated makes it much more resistant to salt washing,60 suggesting that this type of membrane association is determined by both the type of prenyl group and polybasic domain.
Frankincense diterpenes as a bio-source for drug discovery
Published in Expert Opinion on Drug Discovery, 2022
Hidayat Hussain, Luay Rashan, Uzma Hassan, Muzaffar Abbas, Faruck L. Hakkim, Ivan R. Green
A prenylaromadendrane-type diterpene core skeleton ‘B’ is the combination of an aromadendrane sesquiterpene (Figure 6; red color) with an attached prenyl group (Figure 6; blue color) via C-15. A prenylaromadendrane-type diterpene named olibanumol D (67) was produce by B. carterii and illustrated inhibitory effects of 35.8% on NO production [85]. In another report, B. carterii also produced another seven prenylaromadendrane-type diterpenes, boscartols A − C (68–70), E (71), F (72), H (73), and I (74). Of note, compound 72 bearing an aldehyde group at the C-20 position, was the most potent and illustrated hepatoprotective activity with a percentage inhibition: 69.6%, which effect was 1.6 times higher than the standard bicyclol (percentage inhibition: 42.5%). In addition, the hepatoprotective activity of compound 71 which has three additional hydroxyl groups (compared to compound 72), was less active than 72 but did demonstrate significant inhibition effects of 36.3% followed by compound 74 with 33.6%. However, these effects were lower than the standard bicyclol (Figure 6). Notably, the position of the double bond at C-17/C-18 slightly decreased activity because diterpene 69 (33.6%) illustrated better effects than compound 68 (26.1%). Additionally, stereochemistry at C-16 plays a role in biological activity because compounds 73 (24.3%) and 74 (33.6%) are epimers [86].
Differential effects of genistein and 8-prenylgenistein on reproductive tissues in immature female mice
Published in Pharmaceutical Biology, 2019
Xiao-Li Li, Li Sui, Fu-Hui Lin, Yin Lian, Lian-Zhong Ai, Yan Zhang
Prenylated flavanones are a unique class of naturally occurring flavonoids characterized by the presence of a prenylated side chain in the flavonoid skeleton (Štulíková et al. 2018). The research on prenylated flavanones is a topic of great interest due to their promising and diverse bioactivities on multi-targeting tissues (Štulíková et al. 2018; Zhu et al. 2018). Intriguingly, the structure–activity relationship studies demonstrated that the prenylation at site 8 of ring A in flavonoid structure could strengthen the activities of the original compound as well as potentially produce more effects (Chen et al. 2014). The prenyl group contributed to oestrogenic activity of phytoestrogen 8-prenynaringenin (Štulíková et al. 2018; Hoffmann et al. 2016) which showed stronger bone-protective effects than that of naringenin (Ming et al. 2013).
Competitive α-glucosidase inhibitors, dihydrobenzoxanthones, from the barks of Artocarpus elasticus
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Janar Jenis, Aizhamal Baiseitova, Sang Hwa Yoon, Chanin Park, Jeong Yoon Kim, Zuo Peng Li, Keun Woo Lee, Ki Hun Park
Compound 5 had the molecular formula C30H32O7 made on basis of HRFABMS data with [M + H]+ ion at 505.2216 (calcd 505.2148). It has a feature of the flavone skeleton with hydrogen bonding C5-OH (δH 13.2) and α, β-unsaturated carbonyl (δC 183.0). The ring A having five substituents was confirmed a singlet H6 (δH 6.15, s) which has HMBC correlation with C5 (δC 162.9) and C7 (δC 160.4). Two singlet protons of H3' (δH 6.59) and H6' (δH 6.88) showed four substituents of ring B. The positions of H3' and H6' were confirmed by HMBC correlation of H3' with C2' (δC 149.7) and C4' (δC 149.8), and H6' with C1' (δC 111.5) and C5' (δC 139.1). The prenyl group was confirmed by a typical coupling network across H9/H10/H12/H13 in the COSY spectrum. The position of a group was confirmed by HMBC of H9 (δH 3.14) with C3 (δC 121.7), and carbonyl C4 (δC 183.0). The presence of pyran moiety was deduced from proton coupling of H14 (δH 5.61, d) with H14a (δH 5.61, d) and HMBC between H14a and oxygenated carbon C15 (δC 81.4). The proton coupling network across H17/H18/H19/H21/H22 indicated the presence of the 2-methyl-2-pentenyl group. The locations of 2-methyl-2-pentenyl and methyl groups were confirmed by HMBC correlations of both H16 (δH 1.42) and H17 (δH 1.69) with C15 (Figures S10–S13 in Supplementary Material and Table S1 in Supplementary Material). Thus compound 5 was determined to be (-)-2-(2,4,5-trihydroxyphenyl)-3-(3-methyl-2-buten-1-yl)-5-hydroxy-8-methyl-8-(4-methyl-3-penten-1-yl)-4H,8H-benzo[1,2-b:3,4-b']dipyran-4-one, named as artoflavone B.