Biotin–Protein Bond: Instability and Structural Modification to Provide Stability for In Vivo Applications

2008 ◽  
pp. 209-220 ◽  
Author(s):  
Donald M. Mock ◽  
Anna Bogusiewicz
Keyword(s):  
Structural Modification

Combinatorial Synthesis of Novel 9R-Acyloxyquinine Derivatives as Insecticidal Agents

2020 ◽  
Vol 23 (2) ◽  
pp. 111-118
Author(s):  
Zhiping Che ◽  
Jinming Yang ◽  
Di Sun ◽  
Yuee Tian ◽  
Shengming Liu ◽  
...  
Keyword(s):  
Natural Products ◽  
Double Bond ◽  
Insecticidal Activity ◽  
Structural Modification ◽  
Combinatorial Synthesis ◽  
Hydroxyl Group ◽  
Botanical Insecticide ◽  
Mythimna Separata ◽  
Lead Compounds

Background: It is one of the effective ways for pesticide innovation to develop new insecticides from natural products as lead compounds. Quinine, the main alkaloid in the bark of cinchona tree as well as in plants in the same genus, is recognized as a safe and potent botanical insecticide to many insects. The structural modification of quinine into 9R-acyloxyquinine derivatives is a potential approach for the development of novel insecticides, which showed more toxicity than quinine. However, there are no reports on the insecticidal activity of 9Racyloxyquinine derivatives to control Mythimna separata. Methods: Endeavor to discover biorational natural products-based insecticides, 20 novel 9Racyloxyquinine derivatives were prepared and assessed for their insecticidal activity against M. separata in vivo by the leaf-dipping method at 1 mg/mL. Results: Among all the compounds, especially derivatives 5i, 5k and 5t exhibited the best insecticidal activity with final mortality rates of 50.0%, 57.1%, and 53.6%, respectively. Conclusion: Overall, a free 9-hydroxyl group is not a prerequisite for insecticidal activity and C9- substitution is well tolerated; modification of out-ring double-bond is acceptable, and hydrogenation of double-bond enhances insecticidal activity; Quinine ring is essential and open of it is not acceptable. These preliminary results will pave the way for further modification of quinine in the development of potential new insecticides.

scholarly journals Anthocyanin Pigments: Beyond Aesthetics

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5500
Author(s):  
Bindhu Alappat ◽  
Jayaraj Alappat
Keyword(s):  
Defense Mechanisms ◽  
Structural Modification ◽  
Synthetic Methods ◽  
Isolation And Identification ◽  
Polyphenol Compounds ◽  
Structural Modifications ◽  
New Gene ◽  
The Stability ◽  
Vegetables And Fruits

Anthocyanins are polyphenol compounds that render various hues of pink, red, purple, and blue in flowers, vegetables, and fruits. Anthocyanins also play significant roles in plant propagation, ecophysiology, and plant defense mechanisms. Structurally, anthocyanins are anthocyanidins modified by sugars and acyl acids. Anthocyanin colors are susceptible to pH, light, temperatures, and metal ions. The stability of anthocyanins is controlled by various factors, including inter and intramolecular complexations. Chromatographic and spectrometric methods have been extensively used for the extraction, isolation, and identification of anthocyanins. Anthocyanins play a major role in the pharmaceutical; nutraceutical; and food coloring, flavoring, and preserving industries. Research in these areas has not satisfied the urge for natural and sustainable colors and supplemental products. The lability of anthocyanins under various formulated conditions is the primary reason for this delay. New gene editing technologies to modify anthocyanin structures in vivo and the structural modification of anthocyanin via semi-synthetic methods offer new opportunities in this area. This review focusses on the biogenetics of anthocyanins; their colors, structural modifications, and stability; their various applications in human health and welfare; and advances in the field.

scholarly journals Screening of Insecticidal Activity of Podophyllotoxin Analogues against Athetis dissimilis

2019 ◽  
Vol 14 (1) ◽  
pp. 1934578X1901400 ◽  
Author(s):  
Zhiping Che ◽  
Yuee Tian ◽  
Jinming Yang ◽  
Shengming Liu ◽  
Jia Jiang ◽  
...  
Keyword(s):  
Insecticidal Activity ◽  
Structural Modification ◽  
Plant Secondary Metabolites ◽  
Mortality Rates ◽  
Fourth Instar ◽  
Chemical Structures ◽  
Commercial Plant ◽  
Ongoing Work ◽  
Insecticidal Activities

As our ongoing work on research of natural-product-based insecticidal agents, eighteen podophyllotoxin analogues with diverse chemical structures were evaluated for their insecticidal activities against the pre-fourth-instar larvae of Athetis dissimilis Hampson in vivo at the concentration of 1 mg/mL. Among all the reported analogues, compounds 6, 8, 12, 13, 15 and 17 showed more potent insecticidal activities than matrine, quinine and toosendanin, three commercial plant secondary metabolites. 2′,6′-Dichloropodophyllotoxin (8) and 2′,6′-dichloroepipodophyllotoxin (13) exhibited the most pronounced and promising insecticidal activity with the final corrected mortality rates of greatly 60%. This suggested that variation of chemical structures in the podophyllotoxin skeleton conspicuously has effect on the insecticidal activity profiles of podophyllotoxin analogues. Moreover, SAR revealed that the substituents and configuration were critical for their insecticidal activities. The results may be useful in guiding further design and structural modification of podophyllotoxins in the development of potential novel insecticidal agents.

On the structural modification of 2-nitroimidazole-99mTc(CO)3 complex, a hypoxia marker, for improving in vivo pharmacokinetics

2012 ◽  
Vol 39 (8) ◽  
pp. 1236-1242 ◽  
Author(s):  
Madhava B. Mallia ◽  
Chandan Kumar ◽  
Anupam Mathur ◽  
H.D. Sarma ◽  
Sharmila Banerjee
Keyword(s):  
Structural Modification ◽  
Hypoxia Marker ◽  
In Vivo Pharmacokinetics

scholarly journals Structural Optimization of a Wearable Deep Body Thermometer: From Theoretical Simulation to Experimental Verification

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Ming Huang ◽  
Toshiyo Tamura ◽  
Zunyi Tang ◽  
Wenxi Chen ◽  
Shigehiko Kanaya
Keyword(s):  
Structural Modification ◽  
Measurement Accuracy ◽  
Experimental System ◽  
The Finite Element Method ◽  
Original Design ◽  
Standard Type ◽  
Deep Body Temperature ◽  
Theoretical Simulation ◽  
Deep Body

Deep body temperature (DBT) has yet to be measured continuously in everyday life, even though it is useful in physiological monitoring and chronobiology studies. We tried to address this issue by developing a transcutaneous thermometer based on the dual-heat-flux method (DHFM) invoking the principle of heat transfer, for which measurement error was mitigated by elaborate design. First, a structural modification based on the original design of the DHFM was implemented by the finite element method. Based on the results of the simulations, prototypes were then implemented and tested with an experimental system that mimicked the thermometer being applied to skin. The simulation phase proposed the adoption of an aluminum cover to boost measurement accuracy and suggested that thermometers of different height be chosen according to specified requirements. The results of the mock-up experiments support the modification put forward in the simulation phase: the standard type (15 mm in height) achieved the accuracy with error below 0.3°C while the thin type (9 mm in height) attained accuracy with error less than 0.5°C under normal ambient temperature ranging from 20 to 30°C. Even though the design should also be examinedin vivo, it is believed that this study is an important step in developing a practical noninvasive deep body thermometer.

The dextrans as vehicles for gene and drug delivery

2019 ◽  
Vol 11 (13) ◽  
pp. 1659-1667 ◽  
Author(s):  
Shiyu Huang ◽  
Gangliang Huang
Keyword(s):  
Drug Delivery ◽  
Drug Targets ◽  
Structural Modification ◽  
Deep Understanding ◽  
Delivery Systems ◽  
Research Topic ◽  
Nanodrug Delivery ◽  
And Function ◽  
Drug Vehicle

Dextran has become a hot research topic in drug vehicle material because of its biodegradable, nonspecific cell adhesion, resistance to protein adsorption, low price and ease of structural modification. The fate and changes of dextran in vivo are not fully understood. It is helpful to guide the design and modification of dextran drug vehicles to clarify the changes in the morphology, metabolism and function of drug targets. With the deep understanding of dextran and the emergence of new functional dextran derivatives, its application in nanodrug delivery systems will be more and more, clinically applicable delivery systems may also be available.

scholarly journals Structure-Activity Relationship Study on the Ethyl p-Methoxycinnamate as an Anti-Inflammatory Agent

2018 ◽  
Vol 18 (1) ◽  
pp. 60
Author(s):  
Ismiarni Komala ◽  
Supandi Supandi ◽  
Nurhasni Nurhasni ◽  
Ofa Suzanti Betha ◽  
Eka Putri ◽  
...  
Keyword(s):  
Active Sites ◽  
Structural Modification ◽  
Inflammatory Activity ◽  
Esterification Reaction ◽  
Inflammatory Agent ◽  
Kaempferia Galanga ◽  
Structure Activity ◽  
Anti Inflammatory

Ethyl p-methoxycinnamate (EPMC) (1) has been isolated as a major compound from the rhizome of Kaempferia galanga together with the other compound ethyl cinnamate (2). As reported in the literature, EPMC (1) exhibited a significant in vitro and in vivo anti-inflammatory activity. In this research, we investigated the anti-inflammatory activity of compounds 1 and 2 by using anti-denaturation of heat bovine serum albumin (BSA) method. In order to analyze active sites that are responsible for the anti-inflammatory activity, therefore, it is necessary to conduct structural modification of EPMC (1). The structural modification was performed through re-esterification reaction by using conventional and assistance of the unmodified microwave oven. Evaluation of the results of the bioassay indicated that the ester and methoxy functional groups of EPMC (1) play an important role for the anti-inflammatory activity.

scholarly journals Design, Synthesis, and Biological Evaluation of Desmuramyl Dipeptides Modified by Adamantyl-1,2,3-triazole

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6352
Author(s):  
Vesna Petrović Peroković ◽  
Željka Car ◽  
Josip Draženović ◽  
Ranko Stojković ◽  
Lidija Milković ◽  
...  
Keyword(s):  
Immune Response ◽  
Murine Model ◽  
Structural Modification ◽  
Muramyl Dipeptide ◽  
Biological Evaluation ◽  
Adjuvant Activity ◽  
Design Synthesis ◽  
C Terminus ◽  
Synthesis And Biological Evaluation

Muramyl dipeptide (MDP) is the smallest peptidoglycan fragment able to trigger the immune response. Structural modification of MDP can lead to the preparation of analogs with improved immunostimulant properties, including desmuramyl peptides (DMPs). The aim of this work was to prepare the desmuramyl peptide (L-Ala-D-Glu)-containing adamantyl-triazole moiety and its mannosylated derivative in order to study their immunomodulatory activities in vivo. The adjuvant activity of the prepared compounds was evaluated in a murine model using ovalbumin as an antigen, and compared to the reference adjuvant ManAdDMP. The results showed that the introduction of the lipophilic adamantyl-triazole moiety at the C-terminus of L-Ala-D-Glu contributes to the immunostimulant activity of DMP, and that mannosylation of DMP modified with adamantyl-triazole causes the amplification of its immunostimulant activity.

Recent Progress in Oleanolic Acid: Structural Modification and Biological Activity

2021 ◽  
Vol 21 ◽  
Author(s):  
Wang Wang ◽  
Yutong Li ◽  
Yan Li ◽  
Dejuan Sun ◽  
Hua Li ◽  
...  
Keyword(s):  
Oleanolic Acid ◽  
Structural Modification ◽  
Recent Progress ◽  
Biological Activities ◽  
Biological Effects ◽  
Biologically Active ◽  
In Vivo Models ◽  
Action Mechanisms

: Natural products have been proven as the main source of biologically active compounds, which are potentially useful for drug development. As one of the most studied pentacyclic triterpenes, oleanolic acid (OA) exhibits a broad range of biological activities and serves as a good scaffold for the development of novel derivatives that could be vital in drug discovery for various ailments. Up to now, many of its derivatives with multiple bioactivities have been prepared through chemical modification. This review summarizes the recent reports of OA derivatives (2016-present) and their biological effects and action mechanisms in vitro and in vivo models, and discusses the design of novel and potent derivatives.

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