Methotrexate analogs. 31. Meta and ortho isomers of aminopterin, compounds with a double bond in the side chain, and a novel analog modified at the .alpha.-carbon: chemical and in vitro biological studies [Erratum to document cited in CA109(1):6923u]

1989 ◽  
Vol 32 (12) ◽  
pp. 2582-2582
Author(s):  
Andre Rosowsky ◽  
Henry Bader ◽  
Ronald A. Forsch ◽  
Richard G. Moran ◽  
James H. Freisheim
Keyword(s):  
Double Bond ◽  
Side Chain ◽  
Biological Studies ◽  
Alpha Carbon

scholarly journals Novel Steroidal 5α,8α-Endoperoxide Derivatives with Semicarbazone/Thiosemicarbazone Side-chain as Apoptotic Inducers through an Intrinsic Apoptosis Pathway: Design, Synthesis and Biological Studies

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1209 ◽  
Author(s):  
Liwei Ma ◽  
Haijun Wang ◽  
Jing Wang ◽  
Lei Liu ◽  
Song Zhang ◽  
...  
Keyword(s):  
Hepg2 Cells ◽  
Antitumor Agents ◽  
Human Cancer ◽  
Side Chain ◽  
Design Synthesis ◽  
Apoptosis Pathway ◽  
Human Cancer Cell Lines ◽  
Biological Studies ◽  
Intrinsic Apoptosis Pathway

A series of novel steroidal 5α,8α-endoperoxide derivatives bearing semicarbazone (7a–g) or thiosemicarbazone (7h–k) side chain were designed, synthesized and evaluated for their cytotoxicities in four human cancer cell lines (HepG2, HCT-116, MCF-7, and A549) using the MTT assay in vitro. The results showed that compound 7j exhibited significant cytotoxic activity against HepG2 cells (IC50 = 3.52 μM), being more potent than ergosterol peroxide. Further cellular mechanism studies in HepG2 cells indicated that compound 7j triggered the mitochondrial-mediated apoptosis by decreasing mitochondrial membrane potential (MMP), which was associated with up-regulation of Bax, down-regulation of Bcl-2, activation levels of the caspase cascade, and formation of reactive oxygen species (ROS). The above findings indicated that compound 7j may be used as a promising skeleton for antitumor agents with improved efficacy.

scholarly journals Structure and apoprotein linkages of phycourobilin

1985 ◽  
Vol 226 (3) ◽  
pp. 723-731 ◽  
Author(s):  
S D Killilea ◽  
P O'Carra
Keyword(s):  
Double Bond ◽  
Pyrrole Ring ◽  
Cysteine Residue ◽  
Side Chain ◽  
Ring Nitrogen ◽  
Prosthetic Groups ◽  
Ring Nitrogen Atom ◽  
Alpha Carbon ◽  
Reduced State ◽  
Bridge Position

R-Phycoerythrin contains two covalently bound bilin prosthetic groups, phycoerythrobilin and phycourobilin. The two chromophore types were separated as their peptide-bound derivatives by subjecting tryptic digests of R-phycoerythrin to adsorption chromatography on Sephadex G-25. The structure and apoprotein linkages of the bound phycoerythrobilin were found to be identical with those previously reported for this phycobilin [Killilea, O'Carra & Murphy (1980) Biochem. J. 187, 311-320]. Phycourobilin is a tetrapyrrole, containing no oxo bridges and has the same order of side chains as IX alpha bilins. The chromophore is linked to the peptide through two and possibly three of its pyrrole rings. One linkage possibly consists of an ester bond between the hydroxy group of a serine residue and the propionic acid side chain of one of the inner rings. The second linkage is a labile thioether bond between a cysteine residue and the C2 side chain of pyrrole ring A. The third linkage is a stable thioether bond between a cysteine residue and the alpha-carbon atom of the C2 side chain of pyrrole ring D. Ring D is unsaturated and is attached to ring C through a saturated carbon bridge. Rings B and C have a conjugated system of five bonds, as found in other urobilinoid pigments. Ring A is attached to ring B via a saturated carbon bridge. Both of the alpha-positions of ring A are in the reduced state, but the ring does contain an unsaturated centre (probably a double bond between the beta-carbon and the ring nitrogen atom). The presence of this double bond and its isomerization into the bridge position between rings A and B would explain the extension of the conjugated system of phycourobilin to that of a phycoerythrobilinoid/rhodenoid pigment in acid or alkali.

Synthetic DAF-12 modulators with potential use in controlling the nematode life cycle

2014 ◽  
Vol 465 (1) ◽  
pp. 175-184 ◽  
Author(s):  
María V. Dansey ◽  
Lautaro D. Alvarez ◽  
Gisela Samaja ◽  
Daiana S. Escudero ◽  
Adriana S. Veleiro ◽  
...  
Keyword(s):  
Life Cycle ◽  
Double Bond ◽  
Side Chain ◽  
Antagonist Activity ◽  
Dafachronic Acid ◽  
Potential Use

Introduction of a 24,25-double bond into Δ4-dafachronic acid did not affect agonist DAF-12 activity. Shortening of the side chain resulted in antagonist activity, with 24-hydroxy-4-cholen-3-one being a pure antagonist in vitro and in vivo.

A Novel Scheme for the Synthesis of 21-Acetoxypregna-1,4,9(11)-triene- 17α,21-diol-3,20-dione from 9α-Hydroxyandrostenedione

2020 ◽  
Vol 16 (5) ◽  
pp. 606-610
Author(s):  
Nguyen T. Diep ◽  
Luu D. Huy
Keyword(s):  
Double Bond ◽  
Chemical Synthesis ◽  
Economic Efficiency ◽  
Final Stage ◽  
Side Chain ◽  
Entire Process ◽  
Drug Synthesis ◽  
First Time

Background: Vietnam currently imports up to 90% of the pharmaceuticals it consumes and 100% of the steroid-based pharmaceuticals. The ability for efficient chemical synthesis of the steroids could create commercial opportunities to address this issue. Synthesis of 21-acetoxypregna-1,4,9(11)- triene-17α,21-diol-3,20-dione is considered a key intermediate in the scheme of steroidal drug synthesis. Previous synthesis attempts of such steroids (corticoids) introduce a double bond at C-1(2) in the final stage of synthesis, which delivers a poor yield and reduces the economic efficiency of the process. Objective: To study and develop a novel and effective method for the synthesis of 21-acetoxypregna- 1,4,9(11)-triene-17α,21-diol-3,20-dione. Methods: Using 9α-hydroxyandrostenedione as a substrate chemical synthesis was performed as follows: pregnane side chain construction at C-17 (acetylene method), introduction of C-1(2) double bond (using SeO2), epimerization of C-17 (via 17-ONO2 ester) and Stork’s iodination. Results: 21-acetoxypregna-1,4,9(11)-triene-17α,21-diol-3,20-dione was prepared from 9α- hydroxyandrostenedione with an improved yield compared to previous attempts. Conclusion: Here, 21-acetoxypregna-1,4,9(11)-triene-17α,21-diol-3,20-dione has been synthesized from 9α-hydroxyandrostenedione based on a novel, effective and commercially feasible scheme. The introduction of the C-1(2) double bond at an earlier stage of the synthesis has increased the economic efficiency of the entire process. For the first time, the indirect epimerization mechanism has been clarified along with the configuration of the C-17 stereo-center which has been confirmed using NOESY data.

scholarly journals Transcription of 4′-thioDNA templates to natural RNA in vitro and in mammalian cells

2015 ◽  
Vol 51 (37) ◽  
pp. 7887-7890 ◽  
Author(s):  
Hideto Maruyama ◽  
Kazuhiro Furukawa ◽  
Hiroyuki Kamiya ◽  
Noriaki Minakawa ◽  
Akira Matsuda
Keyword(s):  
Nucleic Acids ◽  
Mammalian Cells ◽  
Genetic Material ◽  
Rna Polymerases ◽  
Chemically Modified ◽  
Biological Studies ◽  
Modified Nucleic Acids

Synthetic chemically modified nucleic acids, which are compatible with DNA/RNA polymerases, have great potential as a genetic material for synthetic biological studies.

scholarly journals A modular microfluidic system based on a multilayered configuration to generate large-scale perfusable microvascular networks

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Tao Yue ◽  
Da Zhao ◽  
Duc T. T. Phan ◽  
Xiaolin Wang ◽  
Joshua Jonghyun Park ◽  
...  
Keyword(s):  
Large Scale ◽  
Circulatory System ◽  
Vertical Direction ◽  
Microfluidic System ◽  
Vital Role ◽  
Microvascular Networks ◽  
Biological Studies ◽  
Wide Range ◽  
High Flexibility

AbstractThe vascular network of the circulatory system plays a vital role in maintaining homeostasis in the human body. In this paper, a novel modular microfluidic system with a vertical two-layered configuration is developed to generate large-scale perfused microvascular networks in vitro. The two-layer polydimethylsiloxane (PDMS) configuration allows the tissue chambers and medium channels not only to be designed and fabricated independently but also to be aligned and bonded accordingly. This method can produce a modular microfluidic system that has high flexibility and scalability to design an integrated platform with multiple perfused vascularized tissues with high densities. The medium channel was designed with a rhombic shape and fabricated to be semiclosed to form a capillary burst valve in the vertical direction, serving as the interface between the medium channels and tissue chambers. Angiogenesis and anastomosis at the vertical interface were successfully achieved by using different combinations of tissue chambers and medium channels. Various large-scale microvascular networks were generated and quantified in terms of vessel length and density. Minimal leakage of the perfused 70-kDa FITC-dextran confirmed the lumenization of the microvascular networks and the formation of tight vertical interconnections between the microvascular networks and medium channels in different structural layers. This platform enables the culturing of interconnected, large-scale perfused vascularized tissue networks with high density and scalability for a wide range of multiorgan-on-a-chip applications, including basic biological studies and drug screening.

scholarly journals Effect of Gold Nanoparticles and Silicon on the Bioactivity and Antibacterial Properties of Hydroxyapatite/Chitosan/Tricalcium Phosphate-Based Biomicroconcretes

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3854
Author(s):  
Joanna Czechowska ◽  
Ewelina Cichoń ◽  
Anna Belcarz ◽  
Anna Ślósarczyk ◽  
Aneta Zima
Keyword(s):  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
Tricalcium Phosphate ◽  
Setting Time ◽  
Antibacterial Properties ◽  
Bone Substitutes ◽  
Bacterial Strains ◽  
Setting Times ◽  
Biological Studies

Bioactive, chemically bonded bone substitutes with antibacterial properties are highly recommended for medical applications. In this study, biomicroconcretes, composed of silicon modified (Si-αTCP) or non-modified α-tricalcium phosphate (αTCP), as well as hybrid hydroxyapatite/chitosan granules non-modified and modified with gold nanoparticles (AuNPs), were designed. The developed biomicroconcretes were supposed to combine the dual functions of antibacterial activity and bone defect repair. The chemical and phase composition, microstructure, setting times, mechanical strength, and in vitro bioactive potential of the composites were examined. Furthermore, on the basis of the American Association of Textile Chemists and Colorists test (AATCC 100), adapted for chemically bonded materials, the antibacterial activity of the biomicroconcretes against S. epidermidis, E. coli, and S. aureus was evaluated. All biomicroconcretes were surgically handy and revealed good adhesion between the hybrid granules and calcium phosphate-based matrix. Furthermore, they possessed acceptable setting times and mechanical properties. It has been stated that materials containing AuNPs set faster and possess a slightly higher compressive strength (3.4 ± 0.7 MPa). The modification of αTCP with silicon led to a favorable decrease of the final setting time to 10 min. Furthermore, it has been shown that materials modified with AuNPs and silicon possessed an enhanced bioactivity. The antibacterial properties of all of the developed biomicroconcretes against the tested bacterial strains due to the presence of both chitosan and Au were confirmed. The material modified simultaneously with AuNPs and silicon seems to be the most promising candidate for further biological studies.

scholarly journals Development of Spanish Broom and Flax Dressings with Glycyrrhetinic Acid-Loaded Films for Wound Healing: Characterization and Evaluation of Biological Properties

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1192
Author(s):  
Angela Abruzzo ◽  
Concettina Cappadone ◽  
Valentina Sallustio ◽  
Giovanna Picone ◽  
Martina Rossi ◽  
...  
Keyword(s):  
Wound Healing ◽  
Drug Loading ◽  
Healing Process ◽  
In Vitro Release ◽  
Sodium Hyaluronate ◽  
Biological Properties ◽  
Glycyrrhetinic Acid ◽  
Wound Dressings ◽  
Biological Studies

The selection of an appropriate dressing for each type of wound is a very important procedure for a faster and more accurate healing process. So, the aim of this study was to develop innovative Spanish Broom and flax wound dressings, as alternatives to cotton used as control, with polymeric films containing glycyrrhetinic acid (GA) to promote wound-exudate absorption and the healing process. The different wound dressings were prepared by a solvent casting method, and characterized in terms of drug loading, water uptake, and in vitro release. Moreover, biological studies were performed to evaluate their biocompatibility and wound-healing efficacy. Comparing the developed wound dressings, Spanish Broom dressings with GA-loaded sodium hyaluronate film had the best functional properties, in terms of hydration ability and GA release. Moreover, they showed a good biocompatibility, determining a moderate induction of cell proliferation and no cytotoxicity. In addition, the wound-healing test revealed that the Spanish Broom dressings promoted cell migration, further facilitating the closure of the wound.

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