scholarly journals Enzymatic Synthesis of Novel Vitexin Glucosides

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6274
Author(s):  
Jiumn-Yih Wu ◽  
Tzi-Yuan Wang ◽  
Hsiou-Yu Ding ◽  
Yun-Rong Zhang ◽  
Shu-Yuan Lin ◽  
...  

Vitexin is a C-glucoside flavone that exhibits a wide range of pharmaceutical activities. However, the poor solubility of vitexin limits its applications. To resolve this limitation, two glycoside hydrolases (GHs) and four glycosyltransferases (GTs) were assayed for glycosylation activity toward vitexin. The results showed that BtGT_16345 from the Bacillus thuringiensis GA A07 strain possessed the highest glycosylation activity, catalyzing the conversion of vitexin into new compounds, vitexin-4′-O-β-glucoside (1) and vitexin-5-O-β-glucoside (2), which showed greater aqueous solubility than vitexin. To our knowledge, this is the first report of vitexin glycosylation. Based on the multiple bioactivities of vitexin, the two highly soluble vitexin derivatives might have high potential for pharmacological usage in the future.

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 232
Author(s):  
Chien-Min Chiang ◽  
Tzi-Yuan Wang ◽  
Jiumn-Yih Wu ◽  
Yun-Rong Zhang ◽  
Shu-Yuan Lin ◽  
...  

8-Hydroxydaidzein (8-OHDe) is a non-natural isoflavone polyphenol isolated from fermented soybean foods. 8-OHDe exhibits a wide range of pharmaceutical activities. However, both the poor solubility and instability of 8-OHDe limit its applications. To resolve the limitations of 8-OHDe, Deinococcus geothermalis amylosucrase (DgAS) has previously been used to glycosylate 8-OHDe to produce soluble and stable 8-OHDe-7-O-α-glucopyranoside (8-OHDe-7-G) in a 0.5 h reaction time. In this study, we aimed to use DgAS and an extended reaction time to produce 8-OHDe diglucosides. At least three 8-OHDe derivatives were produced after a 24 h reaction time, and two major products were successfully purified and identified as new compounds: 8-OHDe-7-O-[α-glucopyranosyl-(1®6)-α-glucopyranoside] (8-OHDe-7-G2) and 8-OHDe-7,4′-O-α-diglucopyranoside (8-OHDe-7-G-4′-G). 8-OHDe-7-G-4′-G showed a 4619-fold greater aqueous solubility than 8-OHDe. In addition, over 92% of the 8-OHDe diglucosides were stable after 96 h, while only 10% of the 8-OHDe could be detected after being subjected to the same conditions. The two stable 8-OHDe diglucoside derivatives have the potential for pharmacological usage in the future.


Author(s):  
Matthew S. Seligmann

As this book has shown the common conception that ‘Churchill’s “radical phase” was cast to the winds’ when he was put in charge of the Navy in October 1911, although well established in the literature, is not, in fact, accurate.1 The radical President of the Board of Trade, eager to improve the lives of the poor, became the radical Home Secretary, no less enthusiastic for social reform, who then became the radical First Lord of the Admiralty, imbued with both a desire and, perhaps more importantly, a will to intervene in order to better conditions for those who served in the Royal Navy. Accordingly, he embarked upon a major programme of improvement across a wide range of different areas all of which affected the everyday life of sailors. Alcohol intake, sexual behaviour, religious practice, corporal punishment, as well as pay and equality of progression, all came under the spotlight while Churchill was First Lord. Of course, not all of the new measures were successful and not all were progressive in the modern understanding of the term, but all of them represented significant attempts to push forward a radical agenda for change....


Author(s):  
Samuel K. Cohn, Jr.

By exploring the wide range of names given to the ‘new’ sexually transmitted disease—the Great Pox—this chapter dispels notions held for two centuries or more. Instead, no tit-for-tat-naming war among nations accused of carrying the disease ensued. The ‘French disease’ alone became standard in medical texts, but not among commoners and not after the late sixteenth century for physicians. The chapter challenges a second truism of the historiography: that naming meant blaming. Although the disease was named after the French, no laws or pogroms ensued against them or any other ‘other’. However, physicians increasingly identified humans as the essential carriers of this new disease and became concerned with tracking human contacts. By the end of the sixteenth century, medical texts had renamed it the territorially neutral lues venerea. Coincidently, with the rise of this new name, blame placed on women, the poor, and victims of the disease increased.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 844
Author(s):  
Joanna Czogała ◽  
Ewa Pankalla ◽  
Roman Turczyn

This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading to the enhancement in mechanical properties and better plasticizing efficiency. Novel plasticizers have been divided into three groups depending on the replacement strategy, i.e., total replacement, partial replacement, and internal plasticizers. Chemical and physical properties of PVC formulations containing a wide range of plasticizers have been compared, allowing observance of the improvements in polymer performance in comparison to PVC plasticized with conventionally applied bis(2-ethylhexyl) phthalate, di-n-octyl phthalate, bis(2-ethylhexyl) terephthalate and di-n-octyl terephthalate. Among a variety of newly developed plasticizers, we have indicated those presenting excellent migration resistance and advantageous mechanical properties, as well as those derived from natural sources. A separate chapter has been dedicated to the description of a synergistic effect of a mixture of two plasticizers, primary and secondary, that benefits in migration suppression when secondary plasticizer is added to PVC blend.


2019 ◽  
Vol 377 (6) ◽  
Author(s):  
Samson Afewerki ◽  
Armando Córdova

AbstractThe concept of merging enamine activation catalysis with transition metal catalysis is an important strategy, which allows for selective chemical transformations not accessible without this combination. The amine catalyst activates the carbonyl compounds through the formation of a reactive nucleophilic enamine intermediate and, in parallel, the transition metal activates a wide range of functionalities such as allylic substrates through the formation of reactive electrophilic π-allyl-metal complex. Since the first report of this strategy in 2006, considerable effort has been devoted to the successful advancement of this technology. In this chapter, these findings are highlighted and discussed.


2011 ◽  
Vol 12 (1) ◽  
pp. 34 ◽  
Author(s):  
Craig G. Webster ◽  
William W. Turechek ◽  
H. Charles Mellinger ◽  
Galen Frantz ◽  
Nancy Roe ◽  
...  

To the best of our knowledge, this is the first report of GRSV infecting tomatillo and eggplant, and it is the first report of GRSV infecting pepper in the United States. This first identification of GRSV-infected crop plants in commercial fields in Palm Beach and Manatee Counties demonstrates the continuing geographic spread of the virus into additional vegetable production areas of Florida. This information indicates that a wide range of solanaceous plants is likely to be infected by this emerging viral pathogen in Florida and beyond. Accepted for publication 27 June 2011. Published 25 July 2011.


2021 ◽  
Vol 9 (16) ◽  
pp. 28-38
Author(s):  
Anatolii Bezusov ◽  
◽  
Valentyna Krutiakova ◽  
Olena Myroshnichenko ◽  
Nataliia Dotsenko ◽  
...  

Subject of research. Biopesticides are based on live cultures of specially selected beneficial microorganisms with controlled properties. They have a pronounced phytoprotective and stimulating effect, thus providing effective prevention and protection of plants from diseases. The obtained biological product increases productivity, improves the quality and structure of the crop, does not accumulate in plants, which allows to obtain environmentally friendly agricultural products and does not harm the environment. Among the large number of bacteria, as a source of microbiological insecticide is Bacillus thuringiensis, which infects lepidopteran pests and leads to their death. Preparations based on this strain are effective when used in low concentrations of solutions. The Bacillus thuringiensis strain produces several toxins with insecticidal action, including β-exotoxin and δ-endotoxin. Toxic effect is manifested and leads to paralysis of the intestinal tract of parasites. Preparations β-exotoxin and δ-endotoxin are obtained by culturing Bacillus thuringiensis bacteria in a liquid medium. The scientific work proposes a method of industrial production using by-products of vegetable raw materials, which makes it economically feasible to use such substrates. The purpose of the study is the development of technology, formulation of nutrient medium, process parameters for the cultivation of bacteria of the genus Bacillus thuringiensis and obtaining a culture fluid containing substances of the class of biopesticides. Methods. Standard and generally accepted methods of research of bioproducts in biotechnology. The formation of bioinsecticides was established by hydrolysis methods, followed by determination of the component of β-exotoxin – ribose, the formation of octagonal crystals of exotoxin – by microscopic method. Research results. Three variants of nutrient media, which include yeast-polysaccharide complex: corn flour, corn oil, yeast autolysate were developed. The parameters of the bacterial cultivation process were studied. The final product is a paste or powder with a titer of 35 .109 spores in 1 g of the bioproduct. Scope of research results. Microbiological preparations based on Bacillus thuringiensis are highly specific and act only on insect larvae from the classes Lepidoptera and Diptera. The resulting biopesticide can be used against pests of a wide range of vegetable and fruit crops.


2020 ◽  
Vol 3 (2) ◽  
pp. 50
Author(s):  
Tea Kasradze

Financial inclusion is often considered as an access to financial resources for the wide public and small and medium-sized businesses, although it is a much broader concept and includes a wide range of access to quality financial products and services, including loans, deposit services, insurance, pensions and payment systems. Mechanisms for protecting the rights of consumers of financial products and services are also considered to be subject to financial inclusion. Financial inclusion acquires great importance during the pandemic and post-pandemic period. The economic crisis caused by the pandemic is particularly painful for low-income vulnerable population. A large part of the poor population who were working informally has lost source of income due to lockdown from the pandemic. Remittances have also been reduced / minimized, as the remitters had also lost jobs and are unable to send money home. Today, when people die from Coronavirus disease, it may be awkward to talk about the financial side of a pandemic, but the financial consequences can be far-reaching if steps are not taken today to ensure access to and inclusion of financial resources. The paper examines the impact of the pandemic on financial inclusion and the responses of the governments and the financial sectors to the challenge of ensuring the financial inclusion of the poor population and small and medium enterprises.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 393 ◽  
Author(s):  
Jannes van der Merwe ◽  
Jan Steenekamp ◽  
Dewald Steyn ◽  
Josias Hamman

Many active pharmaceutical ingredients (APIs) exhibit poor solubility and low dissolution rates in aqueous environments such as the luminal fluids of the gastrointestinal tract. The oral bioavailability of these compounds is usually very low as a result of their poor solubility properties. In order to improve the bioavailability of these poorly soluble drugs, formulation strategies have been applied as a means to improve their aqueous solubility and dissolution rates. With respect to formulation approaches, excipients can be incorporated in the formulation to assist in the dissolution process of the drug, or specialized dosage forms can be formulated that improve dissolution rate through various mechanisms. This paper provides an overview of selected excipients (e.g., alkalinizing agents, surfactants and sugars) that can be used in formulations to increase the dissolution rate as well as specialized dosage forms such as self-emulsifying delivery systems and formulation techniques such as inclusion complexes and solid dispersions. These formulation approaches are discussed with available examples with specific reference to positive outcomes in terms of drug solubility and bioavailability enhancement.


2016 ◽  
Vol 11 (4) ◽  
pp. 1934578X1601100
Author(s):  
Qinghu Wang ◽  
Rongjun Wu ◽  
Narenchaoketu Han ◽  
Nayintai Dai ◽  
Jiesi Wu

Two new compounds, named as sacric acid A (1) and sacric acid B (2), were isolated from the EtOAc extract of Artemisia sacrorum Ledeb. This is the first report on the structure elucidation of these compounds based on UV, IR, and extensive 1D and 2D NMR spectroscopic, and ESI-MS techniques.


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