- Design, Synthesis and Structure-Activity Relationship Studies of Glycosylated Derivatives of Marine Natural Product Lamellarin D
-
Lamellarin D, a marine natural product, acts as a potent inhibitor of DNA topoisomerase I (Topo I). To modify its physicochemical property and biological activity, a series of mono- and di-glycosylated derivatives were designed and synthesized through 22–26 multi-steps. Their inhibition of human Topo I was evaluated, and most of the glycosylated derivatives exhibited high potency in inhibiting Topo I activity as well as lamellarin D. All the 15 target compounds were evaluated for their cytotoxic activities against five human cancer cell lines. The typical lamellarin derivative ZL?3 exhibited the best activity with IC50 values of 3 nM, 10 nM, and 15 nM against human lung cancer A549 cells, human colon cancer HCT116 cells and human hepatocellular carcinoma HepG2 cells. Compound ZL?1 exhibited anti-cancer activity with IC50 of 14 nM and 24 nM against human colon cancer HCT116 cells and human hepatocellular carcinoma HepG2 cells, respectively. Cell cycle analysis in MDA-MB-231 suggested ZL?3 inhibited cell growth through arresting cells at the G2/M phase of the cell cycle. Further tests showed a significant improvement in aqueous solubility of ZL?1 and ZL?7. This study suggested that glycosylation could be utilized as a useful strategy to optimize lamellarin D derivatives as Topo I inhibitors and anticancer agents.
- Zheng, Liuliu,Gao, Tingting,Ge, Zhiwei,Ma, Zhongjun,Xu, Jinzhong,Ding, Wanjing,Shen, Li
-
-
- Oxygen-Free Regioselective Biocatalytic Demethylation of Methyl-phenyl Ethers via Methyltransfer Employing Veratrol- O-demethylase
-
The cleavage of aryl methyl ethers is a common reaction in chemistry requiring rather harsh conditions; consequently, it is prone to undesired reactions and lacks regioselectivity. Nevertheless, O-demethylation of aryl methyl ethers is a tool to valorize natural and pharmaceutical compounds by deprotecting reactive hydroxyl moieties. Various oxidative enzymes are known to catalyze this reaction at the expense of molecular oxygen, which may lead in the case of phenols/catechols to undesired side reactions (e.g., oxidation, polymerization). Here an oxygen-independent demethylation via methyl transfer is presented employing a cobalamin-dependent veratrol-O-demethylase (vdmB). The biocatalytic demethylation transforms a variety of aryl methyl ethers with two functional methoxy moieties either in 1,2-position or in 1,3-position. Biocatalytic reactions enabled, for instance, the regioselective monodemethylation of substituted 3,4-dimethoxy phenol as well as the monodemethylation of 1,3,5-trimethoxybenzene. The methyltransferase vdmB was also successfully applied for the regioselective demethylation of natural compounds such as papaverine and rac-yatein. The approach presented here represents an alternative to chemical and enzymatic demethylation concepts and allows performing regioselective demethylation in the absence of oxygen under mild conditions, representing a valuable extension of the synthetic repertoire to modify pharmaceuticals and diversify natural products.
- Grimm, Christopher,Lazzarotto, Mattia,Pompei, Simona,Schichler, Johanna,Richter, Nina,Farnberger, Judith E.,Fuchs, Michael,Kroutil, Wolfgang
-
p. 10375 - 10380
(2020/10/02)
-
- Kolbe-Schmitt type reaction under ambient conditions mediated by an organic base
-
The combined use of an organic base for resorcinols realized a Kolbe-Schmitt type reaction under ambient conditions. When resorcinols (3-hydroxyphenol derivatives) were treated with DBU under a carbon dioxide atmosphere, nucleophilic addition to carbon dioxide proceeded to afford the corresponding salicylic acid derivatives in high yields.
- Sadamitsu, Yuta,Okumura, Akira,Saito, Kodai,Yamada, Tohru
-
p. 9837 - 9840
(2019/08/20)
-
- IRE-1α INHIBITORS
-
PROBLEM TO BE SOLVED: To provide compounds which directly inhibit inositol requiring enzyme 1 (IRE-1α activity) in vitro, prodrugs, and pharmaceutically acceptable salts thereof. SOLUTION: The present invention provides a compound represented by formula (A) [R3 and R4 are H or the like; Q5-Q8, together with the benzene ring to which they are attached, form a benzofused ring, where at least one of Q5-Q8 is a heteroatom selected from N, O, and S. COPYRIGHT: (C)2016,JPOandINPIT
- -
-
-
- Design and total synthesis of Mannich derivatives of marine natural product lamellarin D as cytotoxic agents
-
Enlightened by the modification route from Camptothecin (CPT) to Topotecan and based on classical drug design theory, a series of Mannich derivatives of lamellarin D were designed and synthesized in 26-27 steps starting from vanillin and isovanilin. All synthesized compounds were then biologically evaluated for their in vitro anti-cancer activities and Topo I inhibitory activities. The results showed that most target compounds exhibited Topo I inhibitory activities in equivalent level with that of lamellarin D. Compound SL-9 exhibited better Topo I inhibitory activity than that of lamellarin D. Compounds SL-2, SL-3, SL-4, SL-5 and SL-11 exhibited better anti-proliferative activity against HT-29 cells than that of lamellarin D.
- Shen, Li,Xie, Nan,Yang, Bo,Hu, Yongzhou,Zhang, Yongmin
-
p. 807 - 817
(2014/10/15)
-
- Revision of the structure and total synthesis of altenuisol
-
A total synthesis of the reported structure of altenuisol is described. Comparison of the 1H NMR spectra of the synthesized compound and of the natural product revealed that the originally proposed structure was not correct. Consequently, two constitutional isomers were synthesized. The spectra of one of these compounds - a structure originally proposed as the structure of altertenuol - matched perfectly with the spectra of the natural product. The total synthesis of altenuisol was thus achieved starting with phloroglucinic acid and protocatechuic aldehyde in 10 steps and in 23% yield, where the longest linear sequence consisted of 6 steps. The key step was a Suzuki coupling with concomitant formation of the lactone ring. Whether altertenuol is identical with altenuisol could not be decided. Total synthesis of altenuisol, a minor toxin in ubiquitous Alternaria spp. revealed that the originally proposed structure was not correct. Altenuisol was proved to have an isomeric structure by total synthesis. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
- Nemecek, Gregor,Cudaj, Judith,Podlech, Joachim
-
scheme or table
p. 3863 - 3870
(2012/09/25)
-
- CHROMONE INHIBITORS OF S-NITROSOGLUTATHIONE REDUCTASE
-
The present invention is directed to inhibitors of S-nitrosoglutathione reductase (GSNOR), pharmaceutical compositions comprising such GSNOR inhibitors, and methods of making and using the same.
- -
-
Page/Page column 43-44
(2011/09/15)
-
- NOVOBIOCIN ANALOGUES AND TREATMENT OF POLYCYSTIC KIDNEY DISEASE
-
Novobiocin analogues are useful in methods of treating, inhibiting, and/or preventing cyst formation in autosomal dominant polycystic kidney disease (ADPKD) in a subject. The disclosure provides methods of treating ADPKD comprising administering a therapeutically effective amount of a coumarin-3-carboxamide novobiocin analogue. Accordingly, the method can include administering a novobiocin analogue in a therapeutically effective amount for reducing levels of mTOR pathway phosphoproteins P-mTOR, P-Akt and P-S6K, or combinations thereof. Further, the method can include administering a novobiocin analogue in a therapeutically effective amount for reducing levels of Hsp-90 client proteins CFTR, ErbB2, c-Raf and Cdk4, or combinations thereof.
- -
-
-
- PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
-
The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
- -
-
-
- Reaction of phenols with the 2,2-diphenyl-1-picrylhydrazyl radical. Kinetics and DFT calculations applied to determine ArO-H bond dissociation enthalpies and reaction mechanism
-
(Figure Presented) The formal H-atom abstraction by the 2,2-diphenyl-1-picrylhydrazyl (dpph?) radical from 27 phenols and two unsaturated hydrocarbons has been investigated by a combination of kinetic measurements in apolar solvents and density functional theory (DFT). The computed minimum energy structure of dpph? shows that the access to its divalent N is strongly hindered by an ortho H atom on each of the phenyl rings and by the o-NO2 groups of the picryl ring. Remarkably small Arrhenius pre-exponential factors for the phenols [range (1.3-19) × 105 M-1 s-1] are attributed to steric effects. Indeed, the entropy barrier accounts for up to ca. 70% of the free-energy barrier to reaction. Nevertheless, rate differences for different phenols are largely due to differences in the activation energy, Ea,1 (range 2 to 10 kcal/mol). In phenols, electronic effects of the substituents and intramolecular H-bonds have a large influence on the activation energies and on the ArO-H BDEs. There is a linear Evans-Polanyi relationship between E a,1 and the ArO-H BDEs: Ea,1/kcal x mol-1 = 0.918 BDE(ArO-H)/kcal x mol-1 - 70.273. The proportionality constant, 0.918, is large and implies a "late" or "product-like" transition state (TS), a conclusion that is congruent with the small deuterium kinetic isotope effects (range 1.3-3.3). This Evans-Polanyi relationship, though questionable on theoretical grounds, has profitably been used to estimate several ArO-H BDEs. Experimental ArO-H BDEs are generally in good agreement with the DFT calculations. Significant deviations between experimental and DFT calculated ArO-H BDEs were found, however, when an intramolecular H-bond to the O? center was present in the phenoxyl radical, e.g., in ortho semiquinone radicals. In these cases, the coupled cluster with single and double excitations correlated wave function technique with complete basis set extrapolation gave excellent results. The TSs for the reactions of dpph ? with phenol, 3- and 4-methoxyphenol, and 1,4-cyclohexadiene were also computed. Surprisingly, these TS structures for the phenols show that the reactions cannot be described as occurring exclusively by either a HAT or a PCET mechanism, while with 1,4-cyclohexadiene the PCET character in the reaction coordinate is much better defined and shows a strong π-π stacking interaction between the incipient cyclohexadienyl radical and a phenyl ring of the dpph? radical.
- Foti, Mario C.,Daquino, Carmelo,Mackie, Iain D.,DiLabio, Gino A.,Ingold
-
experimental part
p. 9270 - 9282
(2009/04/07)
-
- A simple synthesis of 7,4′-dihydroxy-6-methoxyisoflavone, glycitein, the third soybean isoflavone
-
4-Methoxyresorcinol (3) was synthesized as the precursor for glycitein (6) synthesis by the oxidation of 3-hydroxy-4-methoxybenzaldehyde (1) to the aryl formate with H2O2 and a catalytic amount of SeO2. Glycitein (6) was synthesized by cyclization of 2,4,4′-trihydroxy-5-methoxydeoxybenzoin (5) with N,N-dimethylformamide, boron trifluoride diethyl ether, and methanesulfonyl chloride in a microwave oven.
- Lang'at-Thoruwa, Caroline,Song, Tong T.,Hu, Jiang,Simons, Andrean L.,Murphy, Patricia A.
-
p. 149 - 151
(2007/10/03)
-
- An improved and large scale synthesis of the natural coumarin scopoletin
-
Isovanillin was oxidized with magnesium monoperoxyphthalate to 4-methoxyresorcinol (2) and the latter was reacted with 3-oxo-propionic acid ethylester prepared in situ to give scopoletin (1). These reactions can be achieved in kg scale in high yields.
- Hauer,Ritter,Grotemeier
-
p. 737 - 738
(2007/10/03)
-
- Baeyer-Villiger oxidation of β-aryl substituted unsaturated carbonyl compounds with hydrogen peroxide and catalytic selenium dioxide
-
A simple and cheap oxidative procedure using 30% H2O2 and catalytic SeO2 allows to transform 2-aralkylidenecycloalkanones and hydroxy- or alkoxybenzaldehydes to give, in high yields, enollactones and arylformates, respectively.
- Guzman,Mendoza,Garcia,Garibay,Oliveras,Maldonado
-
p. 2121 - 2133
(2007/10/02)
-
- Mechanistic Studies of Selective Catechol Formation from o-Methoxyphenols using a Copper(II)-Ascorbic Acid-Dioxygen System
-
Mechanistic details of selective conversion of o-methoxyphenols to the corresponding catechols using a Cu2+-ascorbic acid-O2 system, were studied. 2,5-Dimethoxyphenol was converted predominantly to the o-demethylated compound and partially to the m-demethylated one.Anisole with no phenolic hydroxy group was much less reactive.When guaiacol (1). guaiacol and 2-methoxy-6-methoxyphenol was used as substrates, moderate intermolecular and intramolecular kinetic isotope effects were observed (1.4-1.9). Catechol was derived from 1 in nine-fold excess over catechol when the reaction was run in an 18O2 atmosphere with natural water as a solvent, though no catechol was formed when using natural O2 and H218O.It was determined that the Cu2+-ascorbic acid-O2 system operates in a monooxygenase mode because the oxygen atom of dioxygen (not water) was incorporated into the products, and this oxidative conversion proceeded mainly via ipso-substitution at the methoxy position, probably with hydroxyl radical coordinated to the cupric ion as the active oxygen species.
- Aihara, Kazuhiro,Urano, Yasuteru,Higuchi, Tsunehiko,Hirobe, Masaaki
-
p. 2165 - 2170
(2007/10/02)
-