scholarly journals Microwave-Assisted Desulfation of the Hemolytic Saponins Extracted from Holothuria scabra Viscera

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 537
Author(s):  
Philippe Savarino ◽  
Emmanuel Colson ◽  
Guillaume Caulier ◽  
Igor Eeckhaut ◽  
Patrick Flammang ◽  
...  

Saponins are plant and marine animal specific metabolites that are commonly considered as molecular vectors for chemical defenses against unicellular and pluricellular organisms. Their toxicity is attributed to their membranolytic properties. Modifying the molecular structures of saponins by quantitative and selective chemical reactions is increasingly considered to tune the biological properties of these molecules (i) to prepare congeners with specific activities for biomedical applications and (ii) to afford experimental data related to their structure–activity relationship. In the present study, we focused on the sulfated saponins contained in the viscera of Holothuria scabra, a sea cucumber present in the Indian Ocean and abundantly consumed on the Asian food market. Using mass spectrometry, we first qualitatively and quantitatively assessed the saponin content within the viscera of H. scabra. We detected 26 sulfated saponins presenting 5 different elemental compositions. Microwave activation under alkaline conditions in aqueous solutions was developed and optimized to quantitatively and specifically induce the desulfation of the natural saponins, by a specific loss of H2SO4. By comparing the hemolytic activities of the natural and desulfated extracts, we clearly identified the sulfate function as highly responsible for the saponin toxicity.

2018 ◽  
Vol 15 (8) ◽  
pp. 1109-1123
Author(s):  
Jonas da Silva Santos ◽  
Joel Jones Junior ◽  
Flavia M. da Silva

Background: We present here the synthesis of 1,3-thiazolidin-4-one (1) and its functionalised analogues, such as the classical isosteres, glitazone (1,3-thiazolidine-2,4-dione) (2), rhodanine (2-thioxo-1,3- thiazolidin-4-one) (3) and pseudothiohydantoin (2-imino-1,3-thiazolidin-4-one) (4) started in the midnineteenth century to the present day (1865-2018). Objective: The review focuses on the differences in the representation of the molecular structures discussed here over time since the first discussions about the structural theory by Kekulé, Couper and Butlerov. Moreover, advanced synthesis methodologies have been developed for obtaining these functional group, including green chemistry. We discuss about its structure and stability and we show the great biological potential. Conclusion: The 1,3-thiazolidin-4-one nucleus and functionalised analogues such as glitazones (1,3- thiazolidine-2,4-diones), rhodanines (2-thioxo-1,3-thiazolidin-4-ones) and pseudothiohydantoins (2-imino-1,3- thiazolidine-2-4-ones) have great pharmacological importance, and they are already found in commercial pharmaceuticals. Studies indicate a promising future in the area of medicinal chemistry with potential activities against different diseases. The synthesis of these nuclei started in the mid-nineteenth century (1865), with the first discussions about the structural theory by Kekulé, Couper and Butlerov. The present study has demonstrated the differences in the representations of the molecular structures discussed here over time. Since then, various synthetic methodologies have been developed for obtaining these nuclei, and several studies on their structural and biological properties have been performed. Different studies with regards to the green synthesis of these compounds were also presented here. This is the result of the process of environmental awareness. Additionally, the planet Earth is already showing clear signs of depletion, which is currently decreasing the quality of life.


Nanoscale ◽  
2015 ◽  
Vol 7 (48) ◽  
pp. 20460-20473 ◽  
Author(s):  
Tianshu Wu ◽  
Keyu He ◽  
Qinglin Zhan ◽  
Shengjun Ang ◽  
Jiali Ying ◽  
...  

As quantum dots (QDs) are widely used in biomedical applications, the number of studies focusing on their biological properties is increasing.


Author(s):  
Weibing Teng ◽  
Joseph Cappello ◽  
Xiaoyi Wu

Genetic engineering of protein-based materials provides material scientists with high levels of control in material microstructures, properties, and functions [1]. For example, multi-block protein copolymers in which individual block may possess distinct mechanical or biological properties have been biosynthesized [2, 3]. Polypeptide sequences derived from well-studied structural proteins (e.g., collagen, silk, elastin) are often used as motifs in the design and synthesis of new protein-based material, in which new functional groups may be incorporated. In this fashion, we have produced a series of silk-elastin-like proteins (SELPs) consisting of polypeptide sequences derived from silk of superior mechanical strength and elastin that is extremely durable and resilient [2, 4]. Notably, the silk-like blocks are capable of crystallizing to form virtual cross-links between elastin-mimetic sequences, which, in turn, lower the crystallinity of the silk-like blocks and thus enhance the solubility of SELPs. Consequently, SELPs may be fabricated into useful structures for biomedical applications, including drug delivery. In this study, we will characterize viscoelastic properties of SELPs, which are particularly relevant to tissue engineering applications.


2021 ◽  
Vol 06 ◽  
Author(s):  
Varun Saxena ◽  
Lalit Pandey ◽  
T. S. Srivatsan

Background: Hydroxyapatite (HAp) is one of the most studied biomimic for biomedical applications. Specially, nano-HAp has been utilized for bone tissue engineering various orthopedic applications. HAp possesses various suitable properties such as bioactivity, biodegradability and cell proliferation efficiency for bone tissue engineering applications. Yet, lacks in self-antibacterial activity, high surface area and target efficiency. Results: In this directioon, researchers have focused on exploring the required surface as well as the inherent properties of HAp at the nanoscale. These properties are largely dependent on the composition, size and morphology of the nano-HAp. Hence, nano-HAp has been found to be an excellent candidate with an attractive combination of properties for selection and use in biomedical applications, those required to enhanced biological responses. Further, depending on the type of application, these factors can be tuned to optimize the performance. Conclusion: In this review article, we focus on the chemical structure of HAp and the routes chosen and used for the synthesis of the nano-HAp. The role of various parameters in controlling synthesis at the nanoscale are presented and briefly discussed. In addition, we provide an overview of the various applications for the pristine and doped nano-HAp with recent examples in areas spanning the following: (i) bone tissue engineering applications, (ii) drug delivery applications, (iii) surface coatings, and (iv) scaffolds. The effect of chemical composition on the mechanical properties, surface properties and biological properties are also highlighted. Nano-HAp is found to be highly proficient for its biomedical applications, especially for bone tissue engineering applications. The nano-sized properties enhances the biological responses. The dopant ions that replaces the Ca ion into the hydroxyapatite (HAp) lattice plays a crucial role in its biomedical applications


Marine Drugs ◽  
2019 ◽  
Vol 17 (12) ◽  
pp. 654 ◽  
Author(s):  
Ana Isabel Barbosa ◽  
Ana Joyce Coutinho ◽  
Sofia A. Costa Lima ◽  
Salette Reis

The use of marine-origin polysaccharides has increased in recent research because they are abundant, cheap, biocompatible, and biodegradable. These features motivate their application in nanotechnology as drug delivery systems; in tissue engineering, cancer therapy, or wound dressing; in biosensors; and even water treatment. Given the physicochemical and bioactive properties of fucoidan and chitosan, a wide range of nanostructures has been developed with these polysaccharides per se and in combination. This review provides an outline of these marine polysaccharides, including their sources, chemical structure, biological properties, and nanomedicine applications; their combination as nanoparticles with descriptions of the most commonly used production methods; and their physicochemical and biological properties applied to the design of nanoparticles to deliver several classes of compounds. A final section gives a brief overview of some biomedical applications of fucoidan and chitosan for tissue engineering and wound healing.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Ziyu Ge ◽  
Luming Yang ◽  
Fang Xiao ◽  
Yani Wu ◽  
Tingting Yu ◽  
...  

Graphene family nanomaterials, with superior mechanical, chemical, and biological properties, have grabbed appreciable attention on the path of researches seeking new materials for future biomedical applications. Although potential applications of graphene had been highly reviewed in other fields of medicine, especially for their antibacterial properties and tissue regenerative capacities, in vivo and in vitro studies related to dentistry are very limited. Therefore, based on current knowledge and latest progress, this article aimed to present the recent achievements and provide a comprehensive literature review on potential applications of graphene that could be translated into clinical reality in dentistry.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Boyang Huang

Abstract Carbon nanotubes (CNTs), with unique graphitic structure, superior mechanical, electrical, optical and biological properties, has attracted more and more interests in biomedical applications, including gene/drug delivery, bioimaging, biosensor and tissue engineering. In this review, we focus on the role of CNTs and their polymeric composites in tissue engineering applications, with emphasis on their usages in the nerve, cardiac and bone tissue regenerations. The intrinsic natures of CNTs including their physical and chemical properties are first introduced, explaining the structure effects on CNTs electrical conductivity and various functionalization of CNTs to improve their hydrophobic characteristics. Biosafety issues of CNTs are also discussed in detail including the potential reasons to induce the toxicity and their potential strategies to minimise the toxicity effects. Several processing strategies including solution-based processing, polymerization, melt-based processing and grafting methods are presented to show the 2D/3D construct formations using the polymeric composite containing CNTs. For the sake of improving mechanical, electrical and biological properties and minimising the potential toxicity effects, recent advances using polymer/CNT composite the tissue engineering applications are displayed and they are mainly used in the neural tissue (to improve electrical conductivity and biological properties), cardiac tissue (to improve electrical, elastic properties and biological properties) and bone tissue (to improve mechanical properties and biological properties). Current limitations of CNTs in the tissue engineering are discussed and the corresponded future prospective are also provided. Overall, this review indicates that CNTs are promising “next-generation” materials for future biomedical applications.


Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3794 ◽  
Author(s):  
Xuejin Wu ◽  
Lingyan Jia ◽  
Jiafan Wu ◽  
Yawen Liu ◽  
Hyunuk Kang ◽  
...  

Saponins in the Camellia sinensis seeds have a broad spectrum of biological properties and application potentials. However, up to now, no chromatographic methods have been developed to provide full fingerprinting and quality assurance for these saponins. This research aimed to develop a novel method to tentatively identify and quantify saponins in C. sinensis seeds by ultra-high-performance liquid chromatography coupled with photo-diode array detector and quadrupole time-of-flight mass spectrometry (UPLC-PDA-QTOF-MS/MS), and compare it with the classic vanillin-sulfuric acid assay. Fifty-one triterpene saponins, including six potentially new compounds, were simultaneously detected by UPLC-PDA-MS/MS, and their chemical structures were speculated according to the retention behavior and fragmentation pattern. The total saponin content in the crude extract and the purified saponin fraction of C. sinensis seeds were quantified to be 19.57 ± 0.05% (wt %) and 41.68 ± 0.09% (wt %) respectively by UPLC-PDA at 210 nm, while the corresponding values were determined to be 43.11 ± 3.17% (wt %) and 56.60 ± 5.79% (wt %) respectively by the vanillin-sulfuric acid assay. The developed UPLC-PDA -MS/MS method could determine specified saponins, and is more reliable for quantifying the C. sinensis seed saponins than the classic spectrophotometric method. It is of great significance for the future investigations and applications of these saponins.


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