scholarly journals NDP-rhamnose biosynthesis and rhamnosyltransferases: building diverse glycoconjugates in nature

2021 ◽  
Vol 478 (4) ◽  
pp. 685-701
Author(s):  
Ben A. Wagstaff ◽  
Azul Zorzoli ◽  
Helge C. Dorfmueller
Keyword(s):  
Natural Products ◽  
Drug Discovery ◽  
Scientific Community ◽  
Pathogenic Bacteria ◽  
Vaccine Development ◽  
Ongoing Study ◽  
Deoxy Sugar ◽  
Future Drug

Rhamnose is an important 6-deoxy sugar present in many natural products, glycoproteins, and structural polysaccharides. Whilst predominantly found as the l-enantiomer, instances of d-rhamnose are also found in nature, particularly in the Pseudomonads bacteria. Interestingly, rhamnose is notably absent from humans and other animals, which poses unique opportunities for drug discovery targeted towards rhamnose utilizing enzymes from pathogenic bacteria. Whilst the biosynthesis of nucleotide-activated rhamnose (NDP-rhamnose) is well studied, the study of rhamnosyltransferases that synthesize rhamnose-containing glycoconjugates is the current focus amongst the scientific community. In this review, we describe where rhamnose has been found in nature, as well as what is known about TDP-β-l-rhamnose, UDP-β-l-rhamnose, and GDP-α-d-rhamnose biosynthesis. We then focus on examples of rhamnosyltransferases that have been characterized using both in vivo and in vitro approaches from plants and bacteria, highlighting enzymes where 3D structures have been obtained. The ongoing study of rhamnose and rhamnosyltransferases, in particular in pathogenic organisms, is important to inform future drug discovery projects and vaccine development.

scholarly journals Addressing the Most Neglected Diseases through an Open Research Model: the Discovery of Fenarimols as Novel Drug Candidates for Eumycetoma

2018 ◽  
Author(s):  
Wilson Lim ◽  
Youri Melse ◽  
Mickey Konings ◽  
Hung Phat Duong ◽  
Kimberly Eadie ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Open Source ◽  
Scientific Community ◽  
Galleria Mellonella ◽  
World Health ◽  
Neglected Diseases ◽  
Starting Point ◽  
Madurella Mycetomatis

AbstractEumycetoma is a chronic infectious disease characterized by a large subcutaneous mass, often caused by the fungusMadurella mycetomatis.A combination of surgery and prolonged medication is needed to treat this infection with a success rate of only 30%. There is, therefore, an urgent need to find more effective drugs for the treatment of this disease. In this study, we screened 800 diverse drug-like molecules and identified 215 molecules that were activein vitro.Minimal inhibitory concentrations were determined for the 13 most active compounds. One of the most potent compounds, a fenarimol analogue for which a large analogue library is available, led to the screening of an additional 35 compounds for theirin vitroactivity againstM. mycetomatishyphae, rendering four further hit compounds. To assess thein vivopotency of these hit compounds, aGalleria mellonellalarvae model infected withM. mycetomatiswas used. Several of the compounds identifiedin vitrodemonstrated promising efficacyin vivoin terms of prolonged larval survival and/or reduced fungal burden. The results presented in this paper are the starting point of anOpen Source Mycetoma (MycetOS)approach in which members of the global scientific community are invited to participate and contribute as equal partners. We hope that this initiative, coupled with the promising new hits we have reported, will lead to progress in drug discovery for this most neglected of neglected tropical diseases.Author summaryMycetoma is a poverty-associated disease that was recently recognised as a neglected tropical disease by the World Health Organisation (WHO). This disease can be caused by either bacteria (actinomycetoma) or fungi (eumycetoma). The most common causative agent of mycetoma is the fungusMadurella mycetomatis.Actinomycetoma can be easily treated, but for eumycetoma, the current and only antifungal drug used is only able to successfully treat 30% of patients. Treatment often involves prolonged medication use and amputation of the affected area. This disease is disfiguring and is a social stigma for patients in endemic countries. To improve treatment for patients, we have looked at over 800 diverse drug-like molecules and compounds in hope to develop new drugs in this study. We have identified 215 compounds with activity againstM. mycetomatisin vitro and several in vivo with ourGalleria mellonellalarvae model. We have chosen an open source approach with this study and placed our findings in an online database and made it available to the public. We invite the global scientific community to participate in our study and contribute as equal partners as long as an open source approach is held in hopes to fast track and boost drug discovery for Eumycetoma.

scholarly journals Potentials of marine natural products against malaria, leishmaniasis, and trypanosomiasis parasites: a review of recent articles

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Justus Amuche Nweze ◽  
Florence N. Mbaoji ◽  
Yan-Ming Li ◽  
Li-Yan Yang ◽  
Shu-Shi Huang ◽  
...  
Keyword(s):  
Natural Products ◽  
Drug Discovery ◽  
Marine Natural Products ◽  
Neglected Tropical Diseases ◽  
Marine Organisms ◽  
New Drugs ◽  
Screening Methods ◽  
Pharmaceutical Industries

Abstract Background Malaria and neglected communicable protozoa parasitic diseases, such as leishmaniasis, and trypanosomiasis, are among the otherwise called diseases for neglected communities, which are habitual in underprivileged populations in developing tropical and subtropical regions of Africa, Asia, and the Americas. Some of the currently available therapeutic drugs have some limitations such as toxicity and questionable efficacy and long treatment period, which have encouraged resistance. These have prompted many researchers to focus on finding new drugs that are safe, effective, and affordable from marine environments. The aim of this review was to show the diversity, structural scaffolds, in-vitro or in-vivo efficacy, and recent progress made in the discovery/isolation of marine natural products (MNPs) with potent bioactivity against malaria, leishmaniasis, and trypanosomiasis. Main text We searched PubMed and Google scholar using Boolean Operators (AND, OR, and NOT) and the combination of related terms for articles on marine natural products (MNPs) discovery published only in English language from January 2016 to June 2020. Twenty nine articles reported the isolation, identification and antiparasitic activity of the isolated compounds from marine environment. A total of 125 compounds were reported to have been isolated, out of which 45 were newly isolated compounds. These compounds were all isolated from bacteria, a fungus, sponges, algae, a bryozoan, cnidarians and soft corals. In recent years, great progress is being made on anti-malarial drug discovery from marine organisms with the isolation of these potent compounds. Comparably, some of these promising antikinetoplastid MNPs have potency better or similar to conventional drugs and could be developed as both antileishmanial and antitrypanosomal drugs. However, very few of these MNPs have a pharmaceutical destiny due to lack of the following: sustainable production of the bioactive compounds, standard efficient screening methods, knowledge of the mechanism of action, partnerships between researchers and pharmaceutical industries. Conclusions It is crystal clear that marine organisms are a rich source of antiparasitic compounds, such as alkaloids, terpenoids, peptides, polyketides, terpene, coumarins, steroids, fatty acid derivatives, and lactones. The current and future technological innovation in natural products drug discovery will bolster the drug armamentarium for malaria and neglected tropical diseases.

scholarly journals Preclinical Models of Nontuberculous Mycobacteria Infection for Early Drug Discovery and Vaccine Research

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 641
Author(s):  
Elisa Rampacci ◽  
Valentina Stefanetti ◽  
Fabrizio Passamonti ◽  
Marcela Henao-Tamayo
Keyword(s):  
Drug Discovery ◽  
Vaccine Development ◽  
Nontuberculous Mycobacteria ◽  
Critical Role ◽  
Developed Countries ◽  
Alternative Methods ◽  
In Vivo Models ◽  
Early Drug

Nontuberculous mycobacteria (NTM) represent an increasingly prevalent etiology of soft tissue infections in animals and humans. NTM are widely distributed in the environment and while, for the most part, they behave as saprophytic organisms, in certain situations, they can be pathogenic, so much so that the incidence of NTM infections has surpassed that of Mycobacterium tuberculosis in developed countries. As a result, a growing body of the literature has focused attention on the critical role that drug susceptibility tests and infection models play in the design of appropriate therapeutic strategies against NTM diseases. This paper is an overview of the in vitro and in vivo models of NTM infection employed in the preclinical phase for early drug discovery and vaccine development. It summarizes alternative methods, not fully explored, for the characterization of anti-mycobacterial compounds.

scholarly journals Zebrafish as an Emerging Model for Bioassay-Guided Natural Product Drug Discovery for Neurological Disorders

Medicines ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 61 ◽  
Author(s):  
Arjun Pitchai ◽  
Rajesh Kannan Rajaretinam ◽  
Jennifer L. Freeman
Keyword(s):  
Natural Products ◽  
Drug Discovery ◽  
Natural Product ◽  
Neurological Disorders ◽  
Experimental Models ◽  
Bioactive Natural Products ◽  
Natural Product Research ◽  
Model Platform

Most neurodegenerative diseases are currently incurable, with large social and economic impacts. Recently, there has been renewed interest in investigating natural products in the modern drug discovery paradigm as novel, bioactive small molecules. Moreover, the discovery of potential therapies for neurological disorders is challenging and involves developing optimized animal models for drug screening. In contemporary biomedicine, the growing need to develop experimental models to obtain a detailed understanding of malady conditions and to portray pioneering treatments has resulted in the application of zebrafish to close the gap between in vitro and in vivo assays. Zebrafish in pharmacogenetics and neuropharmacology are rapidly becoming a widely used organism. Brain function, dysfunction, genetic, and pharmacological modulation considerations are enhanced by both larval and adult zebrafish. Bioassay-guided identification of natural products using zebrafish presents as an attractive strategy for generating new lead compounds. Here, we see evidence that the zebrafish’s central nervous system is suitable for modeling human neurological disease and we review and evaluate natural product research using zebrafish as a vertebrate model platform to systematically identify bioactive natural products. Finally, we review recently developed zebrafish models of neurological disorders that have the potential to be applied in this field of research.

scholarly journals Cryptosporidiosis: A Potential Anti-diarrheal Natural Product Drug Discovery Journey in Ghana, West Africa

2020 ◽  
pp. 85-93
Author(s):  
Senyo K. Botchie ◽  
Andrew G. Mtewa ◽  
Irene Ayi
Keyword(s):  
Developing Countries ◽  
Natural Products ◽  
Drug Discovery ◽  
Drug Development ◽  
Natural Product ◽  
Causative Organism ◽  
Drug Candidates ◽  
Cause Of Deaths

The overwhelming resistance to current drugs and the exhaustion of drug development interventions, as well as synthetic libraries, have compelled researchers to resort to the use of novel drug candidates derived from natural products. Cryptosporidium, the causative organism of Cryptosporidiosis, is no exception. The diarrhea-causing parasite is known to be the leading cause of deaths in children below age 5 in developing countries like Ghana and second to rotavirus as the causative agent for diarrhea in newborn calves and infants. Currently, the only FDA approved drug for the treatment of Cryptosporidiosis is Nitazoxanide. It is, therefore, needful to develop novel alternative candidates as it could aid in the decrease in child mortality and malnutrition in developing countries. Even though there have been significant limitations into anti-cryptosporidial drug development in vitro and in vivo, essential advancements are being made of which this article addresses the need for research into natural products. Some studies outlined in this paper has stated potential plant extracts showing anti-cryptosporidiosis efficacy. With the wealth of medicinal plant products and Cryptosporidium in vitro culture expertise available in our labs at Noguchi Memorial Institute for Medical research we are certain of making potential significant strides in the world of natural product Cryptosporidium drug discovery in Africa.

Updates on Managing Type 2 Diabetes Mellitus with Natural Products: Towards Antidiabetic Drug Development

2019 ◽  
Vol 25 (39) ◽  
pp. 5395-5431 ◽  
Author(s):  
Fahmida Alam ◽  
Md. Asiful Islam ◽  
Mohammad Amjad Kamal ◽  
Siew Hua Gan
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Natural Products ◽  
Drug Discovery ◽  
Drug Development ◽  
Discovery Process ◽  
Drug Discovery Process

Over the years, natural products have shown success as antidiabetics in in vitro, in vivo studies and clinical trials. Because natural product-derived drugs are more affordable and effective with fewer side-effects compared to conventional therapies, pharmaceutical research is increasingly leaning towards the discovery of new antidiabetic drugs from natural products targeting pathways or components associated with type 2 diabetes mellitus (T2DM) pathophysiology. However, the drug discovery process is very lengthy and costly with significant challenges. Therefore, various techniques are currently being developed for the preclinical research phase of drug discovery with the aim of drug development with less time and efforts from natural products. In this review, we have provided an update on natural products including fruits, vegetables, spices, nuts, beverages and mushrooms with potential antidiabetic activities from in vivo, in vitro and clinical studies. Synergistic interactions between natural products and antidiabetic drugs, and potential antidiabetic active compounds from natural products are also documented to pave the way for combination treatment and new drug discovery, respectively. Additionally, a brief idea of the drug discovery process along with the challenges that arise during drug development from natural products and the methods to conquer those challenges are discussed to create a more convenient future drug discovery process.

Chemical and Bioactive Marine Natural Products of Coral-Derived Microorganisms (2015-2017)

2019 ◽  
Vol 26 (38) ◽  
pp. 6930-6941 ◽  
Author(s):  
Xue-Mei Hou ◽  
Yang Hai ◽  
Yu-Cheng Gu ◽  
Chang-Yun Wang ◽  
Chang-Lun Shao
Keyword(s):  
Natural Products ◽  
Marine Natural Products ◽  
Pathogenic Bacteria ◽  
Tumor Cell Lines ◽  
Biological Targets ◽  
Wide Range ◽  
New Compounds ◽  
Novel Products

: Coral-derived microorganisms are known for their inherent ability to produce novel products of pharmaceutical importance. Nearly 260 marine natural products (MNPs) have been isolated from coral-derived microorganisms till 2014. In the last three years, 118 MNPs have been isolated from coral-associated microorganisms including 46 new compounds, two with a novel skeleton, and four new natural products. Most of them exhibited in vitro or in vivo activities against tumor cell lines, parasites, pathogenic bacteria, fungi and virus. We reviewed the natural products reported from 2015 to 2017 that have a wide range of bioactivities against different biological targets.

Natural Anti-inflammatory compounds as Drug candidates in Alzheimer’s disease

2020 ◽  
Vol 27 ◽  
Author(s):  
Reyaz Hassan Mir ◽  
Abdul Jalil Shah ◽  
Roohi Mohi-ud-din ◽  
Faheem Hyder Potoo ◽  
Mohd. Akbar Dar ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Natural Products ◽  
Protective Action ◽  
New Drugs ◽  
Huperzine A ◽  
Brain Disorder ◽  
Anti Inflammatory

: Alzheimer's disease (AD) is a chronic neurodegenerative brain disorder characterized by memory impairment, dementia, oxidative stress in elderly people. Currently, only a few drugs are available in the market with various adverse effects. So to develop new drugs with protective action against the disease, research is turning to the identification of plant products as a remedy. Natural compounds with anti-inflammatory activity could be good candidates for developing effective therapeutic strategies. Phytochemicals including Curcumin, Resveratrol, Quercetin, Huperzine-A, Rosmarinic acid, genistein, obovatol, and Oxyresvertarol were reported molecules for the treatment of AD. Several alkaloids such as galantamine, oridonin, glaucocalyxin B, tetrandrine, berberine, anatabine have been shown anti-inflammatory effects in AD models in vitro as well as in-vivo. In conclusion, natural products from plants represent interesting candidates for the treatment of AD. This review highlights the potential of specific compounds from natural products along with their synthetic derivatives to counteract AD in the CNS.

Potential for Treatment of Neurodegenerative Diseases with Natural Products or Synthetic Compounds that Stabilize Microtubules

2020 ◽  
Vol 26 (35) ◽  
pp. 4362-4372
Author(s):  
John H. Miller ◽  
Viswanath Das
Keyword(s):  
Natural Products ◽  
Neurodegenerative Diseases ◽  
In Vivo Models ◽  
Synthetic Compounds ◽  
Stabilizing Agents ◽  
Animal Models Of Disease ◽  
Model Studies ◽  
Models Of Disease

No effective therapeutics to treat neurodegenerative diseases exist, despite significant attempts to find drugs that can reduce or rescue the debilitating symptoms of tauopathies such as Alzheimer’s disease, Parkinson’s disease, frontotemporal dementia, amyotrophic lateral sclerosis, or Pick’s disease. A number of in vitro and in vivo models exist for studying neurodegenerative diseases, including cell models employing induced-pluripotent stem cells, cerebral organoids, and animal models of disease. Recent research has focused on microtubulestabilizing agents, either natural products or synthetic compounds that can prevent the axonal destruction caused by tau protein pathologies. Although promising results have come from animal model studies using brainpenetrant natural product microtubule-stabilizing agents, such as paclitaxel analogs that can access the brain, epothilones B and D, and other synthetic compounds such as davunetide or the triazolopyrimidines, early clinical trials in humans have been disappointing. This review aims to summarize the research that has been carried out in this area and discuss the potential for the future development of an effective microtubule stabilizing drug to treat neurodegenerative disease.

Novel Phytochemical Constituents and their Potential to Manage Diabetes

2020 ◽  
Vol 26 ◽  
Author(s):  
Shaik Ibrahim Khalivulla ◽  
Arifullah Mohammed ◽  
Kokkanti Mallikarjuna
Keyword(s):  
Natural Products ◽  
Large Population ◽  
World Health ◽  
In Vivo Studies ◽  
Antidiabetic Activity ◽  
Therapeutic Drug ◽  
Pharmacological Activities ◽  
Chemical Structures

Background: Diabetes is a chronic disease affecting a large population worldwide and stands as one of the major global health challenges to be tackled. According to World Health Organization, about 400 million are having diabetes worldwide and it is the seventh leading cause of deaths in 2016. Plant based natural products had been in use from ancient time as ethnomedicine for the treatment of several diseases including diabetes. As a result of that, there are several reports on plant based natural products displaying antidiabetic activity. In the current review, such antidiabetic potential compounds reported from all plant sources along with their chemical structures are collected, presented and discussed. This kind of reports are essential to pool the available information to one source followed by statistical analysis and screening to check the efficacy of all known compounds in a comparative sense. This kind of analysis can give rise to few numbers of potential compounds from hundreds, whom can further be screened through in vitro and in vivo studies, and human trails leading to the drug development. Methods: Phytochemicals along with their potential antidiabetic property were classified according to their basic chemical skeleton. The chemical structures of all the compounds with antidiabetic activities were elucidated in the present review. In addition to this, the distribution and their other remarkable pharmacological activities of each species is also included. Results: The scrutiny of literature led to identification of 44 plants with antidiabetic compounds (70) and other pharmacological activities. For the sake of information, the distribution of each species in the world is given. Many plant derivatives may exert antidiabetic properties by improving or mimicking the insulin production or action. Different classes of compounds including sulfur compounds (1-4), alkaloids (5-11), phenolic compounds (12-17), tannins (18-23), phenylpropanoids (24-27), xanthanoids (28-31), amino acid (32), stilbenoid (33), benzofuran (34), coumarin (35), flavonoids (36-49) and terpenoids (50-70) were found to be active potential compounds for antidiabetic activity. Of the 70 listed compounds, majorly 17 compounds are from triterpenoids, 13 flavonoids and 7 are from alkaloids. Among all the 44 plant species, maximum number (7) of compounds are reported from Lagerstroemia speciosa followed by Momordica charantia (6) and S. oblonga with 5 compounds. Conclusion: This is the first paper to summarize the established chemical structures of phytochemicals that have been successfully screened for antidiabetic potential and their mechanisms of inhibition. The reported compounds could be considered as potential lead molecules for the treatment of type-2 diabetes. Further, molecular and clinical trials are required to select and establish the therapeutic drug candidates.

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