Garlic
Robert E.C. Wildman, Richard S. Bruno in Handbook of Nutraceuticals and Functional Foods, 2019
Rarely have comparisons of water- and oil-soluble compounds from garlic been examined in the same study. Preclinical studies suggest that garlic extracts of differing composition may inhibit cancer or cardiovascular disease, but it is difficult to compare studies due to the varying doses, times of exposure, animals, cell types, and other experimental procedures.37–41 Differences that occur in response to various preparations very likely relate to the content and effectiveness of individual sulfur constituents. The number of sulfur atoms present in the molecule seems to influence the response with diallyl trisulfide (DATS), generally found to be more effective than DADS, which is better than diallyl sulfide (DAS).42,43 Likewise, the presence of the allyl group generally enhances the response over that provided by the propyl moiety.44
Chemical Synthesis of Core Structures
Helmut Brade, Steven M. Opal, Stefanie N. Vogel, David C. Morrison in Endotoxin in Health and Disease, 2020
Numerous syntheses of oligosaccharide structures related to the enterobacterial Kdo region but also comprising Kdo units attached to the neighboring heptose region and linked to parts of the lipid A entity have been performed since 1980. As one of the major accomplishments, the synthesis of the reducing tetrasaccharide α-Kdo-(2-amino-ethyl)thiopropyl glycosides (D) (6,7). Covalent attachment of the amino-spacer derivatives A, B, or D to ∈-amino groups of lysine residues of a protein may be accomplished by various activation procedures, e.g., with glutardialdehyde or thiophosgene, respectively. Since the reaction and the subsequent coupling step to the protein are performed at neutral or slightly alkaline pH, hydrolysis of the acid-sensitive ketosidic linkages of Kdo and the formation of intramolecular lactones of Kdo moieties may be avoided. Moreover, the allyl group itself or a terminal acrylamide function—attached to the ω-amino group of the spacer derivatives A, B, or D via reaction with acryloyl chloride—may be copolymerized with acrylamide, yielding high molecular weight, water-soluble glycopolymers of type F and G, respectively; these polymers are useful in various immunoassays (7,8). As an example, by using these synthetic antigens, antibody specificities directed against α-Kdo mono- and α-(2→4)-linked Kdo disaccharide epitopes, and against those comprising parts of the glucosamine region, have been described (9–11). Alternatively, core oligosaccharides were coupled to lipid A derivatives containing two amide-linked (R)-3-hydroxytetradecanoyl residues, which may be incorporated into membranes of sheep erythrocytes or liposomes to serve as antigens or inhibitors in passive hemolysis experiments. To illustrate the chemistry involved, the synthesis of the pentasaccharide derivative α-Kdo-(2→4)-α-Kdo-(2→4)-α-Kdo-(2→6)-β-d-GlcNhm-(l→6)-d-GlcNhm 13 [hm = (R)-3-hydroxytetradecanoyl] (Fig. 2) corresponding to a part structure occurring in LPS from S. enterica serovar minnesota R 345 will be described (12).
Oligochitosan-pluronic 127 conjugate for delivery of honokiol
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Zhimei Song, Jingjie Sun, Peizong Deng, Feilong Zhou, Hongmei Xu, Yi Wen, Fangfang Teng, Di Ge, Runliang Feng
Their structures were characterized using 1H-NMR spectrometer (AVANCE III 400 MHz Digital NMR Spectrometer). In the 1H-NMR spectra of CS-F127, there are characteristic peaks of -CH3 and -OCH2(CH)-CH2-O- for F127 at 1.02 and 3.56, respectively (Figure 2). At the same time, the characteristic peaks at 1.92, 2.77 and 3.37–3.74 were assigned to chemical shift signals of -CO-CH3, -CH-NH- and -CH(CH2)-O- in oligo-chitosan [18,19], respectively, suggesting the formation of CS-F127 copolymer. With regard to diamino-F127, triple peak at 1.14 (a) and multiple peaks between 3.28 and 3.65 (b) were attributed to characteristic peaks of F127 chain. Triple peaks at 2.72 (c), 2.92 (d) and 3.23 (e) belonged to methylene hydrogen proton signals of -OCH2CH2CH2SCH2CH2NH2 which was obtained from the radical addition of cysteamine to allyl group in allylated F127. Multiple peak at 1.88 (e) was also assigned to methylene hydrogen proton signal of -OCH2CH2CH2SCH2CH2NH2. These signals were similar to that reported by us [21,28] and Hiki and Kataoka [29].
Synthesis and biological evaluation of celastrol derivatives as potent antitumor agents with STAT3 inhibition
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Shaohua Xu, Ruolan Fan, Lu Wang, Weishen He, Haixia Ge, Hailan Chen, Wen Xu, Jian Zhang, Wei Xu, Yaqian Feng, Zhimin Fan
Firstly, celastrol was esterified with the halides on the carboxyl to obtain the four C-20 ester derivatives 1a–1d (Schemes 1–2). Secondly, on the basis that the carboxyl group has been protected, the C-2 carbonyl group of 1a was reduced by NaBH4, and then directly esterified with cinnamic acid or other carboxy-containing compounds to obtain 2a–2g. After that, their allyl group was de-protected by Pd[P(C6H5)3]4 respectively to obtain a series of novel A-ring double-substituted modified derivatives 3a–3g (Schemes 1). In addition, 2h was obtained through the methylation of 1a with methyl iodide (Schemes 1). 3h and 3i were another two A-ring disubstituted derivatives produced by the reaction of celastrol with corresponding anhydride after C-2 carbonyl group reduction (Schemes 3). Finally, fourteen C-20 amide derivatives 4a–4n were synthesised refer to the literature method 23 (Schemes 4). Among them, 2a–2h, 3a–3h, 4d, 4f, 4h–4n were new synthesised compounds.
Novel 3-chloro-6-nitro-1H-indazole derivatives as promising antileishmanial candidates: synthesis, biological activity, and molecular modelling studies
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Mohamed Mokhtar Mohamed Abdelahi, Youness El Bakri, Chin-Hung Lai, Karthikeyan Subramani, El Hassane Anouar, Sajjad Ahmad, Mohammed Benchidmi, Joel T. Mague, Jelena Popović-Djordjević, Souraya Goumri-Said
The structures of compounds isolated have been identified by 1H NMR and 13 C NMR spectral data. The 1H NMR spectrum (DMSO-d6) of 2 shows an allylic proton signal at 5.23 ppm and a multiplet centred at 6.04 (6.14, 6.03, and 6.01) ppm attributable to vinyl protons CH = CH2. The 13 C NMR spectra of 2 show the presence of a characteristic signal of the allyl group at 133.92 and one at 115.45 ppm corresponding to the vinylic CH and the methylene vinyl group. Two signals correlating to the methylene group adjacent to the nitrogen atoms appear at 51.63 ppm.
Related Knowledge Centers
- Chemical Reaction
- Organic Chemistry
- Substituent
- Methylene Bridge
- Vinyl Group
- Garlic Oil
- Allyl Chloride
- Substrate
- Hydroxy Group
- Carbon–Hydrogen Bond