scholarly journals Chalcone Scaffolds, Bioprecursors of Flavonoids: Chemistry, Bioactivities, and Pharmacokinetics

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7177
Author(s):  
Mithun Rudrapal ◽  
Johra Khan ◽  
Abdul Aziz Bin Dukhyil ◽  
Randa Mohammed Ibrahim Ismail Alarousy ◽  
Emmanuel Ifeanyi Attah ◽  
...  

Chalcones are secondary metabolites belonging to the flavonoid (C6-C3-C6 system) family that are ubiquitous in edible and medicinal plants, and they are bioprecursors of plant flavonoids. Chalcones and their natural derivatives are important intermediates of the flavonoid biosynthetic pathway. Plants containing chalcones have been used in traditional medicines since antiquity. Chalcones are basically α,β-unsaturated ketones that exert great diversity in pharmacological activities such as antioxidant, anticancer, antimicrobial, antiviral, antitubercular, antiplasmodial, antileishmanial, immunosuppressive, anti-inflammatory, and so on. This review provides an insight into the chemistry, biosynthesis, and occurrence of chalcones from natural sources, particularly dietary and medicinal plants. Furthermore, the pharmacological, pharmacokinetics, and toxicological aspects of naturally occurring chalcone derivatives are also discussed herein. In view of having tremendous pharmacological potential, chalcone scaffolds/chalcone derivatives and bioflavonoids after subtle chemical modification could serve as a reliable platform for natural products-based drug discovery toward promising drug lead molecules/drug candidates.

2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Ivana Generalić Mekinić ◽  
Danijela Skroza ◽  
Ivica Ljubenkov ◽  
Višnja Katalinić

Over the last years, great interest has arisen concerning plant stilbenes, especially resveratrol, which has a whole spectrum of positive biological activities. In this study, we investigated the presence of resveratrol monomers (trans- and cis- form) and naturally occurring derivatives of fraas-resveratrol (piceid, astringin and isorhapontin) in phenolic extracts of twenty medicinal plants traditionally used in Croatian folk medicine. The investigated compounds were present in the samples, in free form or as glucosides, and the highest share was found in immortelle, common yarrow and Lamiaceae plants. The obtained results indicate that biological activity of selected medicinal plants can be related to the presence of this valuable group of phytochemicals.


1995 ◽  
Vol 311 (2) ◽  
pp. 371-375 ◽  
Author(s):  
J A Ponasik ◽  
C Strickland ◽  
C Faerman ◽  
S Savvides ◽  
P A Karplus ◽  
...  

The enzyme trypanothione reductase (TR), together with its substrate, the glutathione-spermidine conjugate trypanothione, plays an essential role in protecting parasitic trypanosomatids against oxidative stress and is a target for drug design. Here we show that a naturally occurring spermine derivative, the antihypertensive agent kukoamine A [N1N12-bis(dihydrocaffeoyl)-spermine] inhibits TR as a mixed inhibitor (Ki = 1.8 microM, Kii = 13 microM). Kukoamine shows no significant inhibition of human glutathione reductase (Ki > 10 mM) and thus provides a novel selective drug lead. The corresponding N1N8-bis(dihydrocaffeoyl)spermidine derivative was synthesized and acted as a purely competitive inhibitor with Ki = 7.5 microM. A series of mono- and di-acylated spermines and spermidines were synthesized to gain an insight into the effect of polyamine chain length, the nature and position of the acyl substituent and the importance of conformational mobility. These compounds inhibited TR with Ki values ranging from 11 to 607 microM.


2020 ◽  
Author(s):  
MUBARAK ALAMRI ◽  
Ali Altharawi ◽  
Alhumaidi B. Alabbas ◽  
Manal A. Alossaimi ◽  
Safar M. Alqahtani

Coronavirus disease 2019 (COVID-19) has affected almost every country in the world by causing a global pandemic with a high mortality rate. Lack of an effective vaccine and/or antiviral drugs against SARS-CoV-2, the causative agent, has severely hampered the response to this novel coronavirus. Natural products have long been used in traditional medicines to treat various diseases, and purified phytochemicals from medicinal plants provide a valuable scaffold for the discovery of new drug leads. In the present study, we performed a computational screening of an in-house database composed of ~1000 phytochemicals derived from traditional Saudi medicinal plants with recognised antiviral activity. Structure-based virtual screening was carried out against three druggable SARS-CoV-2 targets, viral RNAdependent RNA polymerase (RdRp), 3-chymotrypsin-like cysteine protease (3CLpro) and papain like protease (PLpro) to identify putative inhibitors that could facilitate the development of potential anti-COVID-19 drug candidates. Computational analyses identified three compounds inhibiting each target, with binding affinity scores ranging from-9.9 to -6.5 kcal/mol. Among these, luteolin 7-rutinoside, chrysophanol 8-(6-galloylglucoside) and kaempferol 7-(6’’-galloylglucoside) bound efficiently to RdRp, while chrysophanol 8-(6galloylglucoside), 3,4,5-tri-O-galloylquinic acid and mulberrofuran G interacted strongly with 3CLpro, and withanolide A, isocodonocarpine and calonysterone bound tightly to PLpro. These potential drug candidates will be subjected to further in vitro and in vivo studies and may assist the development of effective anti-COVID-19 drugs.


2020 ◽  
Author(s):  
MUBARAK ALAMRI ◽  
Ali Altharawi ◽  
Alhumaidi B. Alabbas ◽  
Manal A. Alossaimi ◽  
Safar M. Alqahtani

Coronavirus disease 2019 (COVID-19) has affected almost every country in the world by causing a global pandemic with a high mortality rate. Lack of an effective vaccine and/or antiviral drugs against SARS-CoV-2, the causative agent, has severely hampered the response to this novel coronavirus. Natural products have long been used in traditional medicines to treat various diseases, and purified phytochemicals from medicinal plants provide a valuable scaffold for the discovery of new drug leads. In the present study, we performed a computational screening of an in-house database composed of ~1000 phytochemicals derived from traditional Saudi medicinal plants with recognised antiviral activity. Structure-based virtual screening was carried out against three druggable SARS-CoV-2 targets, viral RNAdependent RNA polymerase (RdRp), 3-chymotrypsin-like cysteine protease (3CLpro) and papain like protease (PLpro) to identify putative inhibitors that could facilitate the development of potential anti-COVID-19 drug candidates. Computational analyses identified three compounds inhibiting each target, with binding affinity scores ranging from-9.9 to -6.5 kcal/mol. Among these, luteolin 7-rutinoside, chrysophanol 8-(6-galloylglucoside) and kaempferol 7-(6’’-galloylglucoside) bound efficiently to RdRp, while chrysophanol 8-(6galloylglucoside), 3,4,5-tri-O-galloylquinic acid and mulberrofuran G interacted strongly with 3CLpro, and withanolide A, isocodonocarpine and calonysterone bound tightly to PLpro. These potential drug candidates will be subjected to further in vitro and in vivo studies and may assist the development of effective anti-COVID-19 drugs.


Author(s):  
R Possa ◽  
P Khotso

The indigenous knowledge of the Basotho makes it simple for this speech community to name their traditional medicinal plants in such a way that they are meaningful; this could also be viewed as an empowerment technique, especially in the economic sphere. Their medicinal plants names seem to be idiomatic and to express certain philosophies of the Basotho society. Creativity is observable in this kind of naming, and many names allude to the kind of remedy that is associated with the medicinal plant. It is therefore the interest of this paper to consider the names of medical plants among the Basotho whose names allude to the remedy they provide. The names of Sesotho medicinal plants and the reasoning of the Basotho in general behind the name and the use of each medicinal plant will be discussed in this article. This paper will further preserve and promote the use of Basotho traditional medicines for the future generation.


2019 ◽  
Vol 18 (8) ◽  
pp. 581-597 ◽  
Author(s):  
Ambreen Fatima ◽  
Yasir Hasan Siddique

Flavonoids are naturally occurring plant polyphenols found universally in all fruits, vegetables and medicinal plants. They have emerged as a promising candidate in the formulation of treatment strategies for various neurodegenerative disorders. The use of flavonoid rich plant extracts and food in dietary supplementation have shown favourable outcomes. The present review describes the types, properties and metabolism of flavonoids. Neuroprotective role of various flavonoids and the possible mechanism of action in the brain against the neurodegeneration have been described in detail with special emphasis on the tangeritin.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2173
Author(s):  
Grace Gar-Lee Yue ◽  
Clara Bik-San Lau ◽  
Ping-Chung Leung

The immune modulating effects of selected herbs deserve careful studies to gain evidence-based support for their further development. We have been working hard on many items of medicinal herbs to gain insight into their immunomodulatory effects relevant to cancer treatment in particular, while infection control is not excluded. Nine of them have been selected to give the results of our exploration on their biological, particularly immunomodulatory activities. Since Hong Kong people especially favor one medicinal mushroom, viz. Coriolus versicolor, a number of clinical trials using Coriolus for cancer-related studies are included in this review. While immune modulation platforms are being built for relevant studies, a brief account on the research targets and related procedures are given.


2021 ◽  
Vol 118 (45) ◽  
pp. e2108458118
Author(s):  
Wariya Sanrattana ◽  
Thibaud Sefiane ◽  
Simone Smits ◽  
Nadine D. van Kleef ◽  
Marcel H. Fens ◽  
...  

Serine proteases are essential for many physiological processes and require tight regulation by serine protease inhibitors (SERPINs). A disturbed SERPIN–protease balance may result in disease. The reactive center loop (RCL) contains an enzymatic cleavage site between the P1 through P1’ residues that controls SERPIN specificity. This RCL can be modified to improve SERPIN function; however, a lack of insight into sequence–function relationships limits SERPIN development. This is complicated by more than 25 billion mutants needed to screen the entire P4 to P4’ region. Here, we developed a platform to predict the effects of RCL mutagenesis by using α1-antitrypsin as a model SERPIN. We generated variants for each of the residues in P4 to P4’ region, mutating them into each of the 20 naturally occurring amino acids. Subsequently, we profiled the reactivity of the resulting 160 variants against seven proteases involved in coagulation. These profiles formed the basis of an in silico prediction platform for SERPIN inhibitory behavior with combined P4 to P4’ RCL mutations, which were validated experimentally. This prediction platform accurately predicted SERPIN behavior against five out of the seven screened proteases, one of which was activated protein C (APC). Using these findings, a next-generation APC-inhibiting α1-antitrypsin variant was designed (KMPR/RIRA; / indicates the cleavage site). This variant attenuates blood loss in an in vivo hemophilia A model at a lower dosage than the previously developed variant AIKR/KIPP because of improved potency and specificity. We propose that this SERPIN-based RCL mutagenesis approach improves our understanding of SERPIN behavior and will facilitate the design of therapeutic SERPINs.


2022 ◽  
pp. 146144562110374
Author(s):  
Katerina Nanouri ◽  
Eleftheria Tseliou ◽  
Georgios Abakoumkin ◽  
Nikos Bozatzis

In this article we illustrate how trainers and trainees negotiate epistemic and deontic authority within systemic family therapy training. Adult education principles and postmodern imperatives have challenged trainers’ and trainees’ asymmetries regarding knowledge (epistemics) and power (deontics), normatively implicated by the institutional training setting. Up-to-date, we lack insight into how trainers and trainees negotiate epistemic and deontic rights in naturally occurring dialog within training. Drawing from discursive psychology and conversation analysis, we present an analysis of eight transcribed, videotaped training seminars from a systemic family therapy training program, featuring three trainers and eleven trainees. Our analysis highlights the dilemmatic ways in which participants resist and affirm the normatively implicated trainers’ deontic and epistemic authority. Trainers are shown as mitigating directives and trainees as resisting them, with both displaying (not)knowing, while attending to concerns about (a)symmetry. We discuss our findings’ implications for systemic family therapy training.


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