1
|
Ayon NJ. High-Throughput Screening of Natural Product and Synthetic Molecule Libraries for Antibacterial Drug Discovery. Metabolites 2023; 13:625. [PMID: 37233666 PMCID: PMC10220967 DOI: 10.3390/metabo13050625] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 04/29/2023] [Accepted: 05/01/2023] [Indexed: 05/27/2023] Open
Abstract
Due to the continued emergence of resistance and a lack of new and promising antibiotics, bacterial infection has become a major public threat. High-throughput screening (HTS) allows rapid screening of a large collection of molecules for bioactivity testing and holds promise in antibacterial drug discovery. More than 50% of the antibiotics that are currently available on the market are derived from natural products. However, with the easily discoverable antibiotics being found, finding new antibiotics from natural sources has seen limited success. Finding new natural sources for antibacterial activity testing has also proven to be challenging. In addition to exploring new sources of natural products and synthetic biology, omics technology helped to study the biosynthetic machinery of existing natural sources enabling the construction of unnatural synthesizers of bioactive molecules and the identification of molecular targets of antibacterial agents. On the other hand, newer and smarter strategies have been continuously pursued to screen synthetic molecule libraries for new antibiotics and new druggable targets. Biomimetic conditions are explored to mimic the real infection model to better study the ligand-target interaction to enable the designing of more effective antibacterial drugs. This narrative review describes various traditional and contemporaneous approaches of high-throughput screening of natural products and synthetic molecule libraries for antibacterial drug discovery. It further discusses critical factors for HTS assay design, makes a general recommendation, and discusses possible alternatives to traditional HTS of natural products and synthetic molecule libraries for antibacterial drug discovery.
Collapse
Affiliation(s)
- Navid J Ayon
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA
| |
Collapse
|
2
|
Hernandez A, Nguyen LT, Dhakal R, Murphy BT. The need to innovate sample collection and library generation in microbial drug discovery: a focus on academia. Nat Prod Rep 2021; 38:292-300. [PMID: 32706349 PMCID: PMC7855266 DOI: 10.1039/d0np00029a] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The question of whether culturable microorganisms will continue to be a viable source of new drug leads is inherently married to the strategies used to collect samples from the environment, the methods used to cultivate microorganisms from these samples, and the processes used to create microbial libraries. An academic microbial natural products (NP) drug discovery program with the latest innovative chromatographic and spectroscopic technology, high-throughput capacity, and bioassays will remain at the mercy of the quality of its microorganism source library. This viewpoint will discuss limitations of sample collection and microbial strain library generation practices. Additionally, it will offer suggestions to innovate these areas, particularly through the targeted cultivation of several understudied bacterial phyla and the untargeted use of mass spectrometry and bioinformatics to generate diverse microbial libraries. Such innovations have potential to impact downstream therapeutic discovery, and make its front end more informed, efficient, and less reliant on serendipity. This viewpoint is not intended to be a comprehensive review of contributing literature and was written with a focus on bacteria. Strategies to discover NPs from microbial libraries, including a variety of genomics and "OSMAC" style approaches, are considered downstream of sample collection and library creation, and thus are out of the scope of this viewpoint.
Collapse
Affiliation(s)
- Antonio Hernandez
- Dept. of Pharmaceutical Sciences, Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA.
| | - Linh T Nguyen
- Dept. of Pharmaceutical Sciences, Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA. and Institute of Marine Biochemistry, Vietnam Academy of Science and Technology, Nghiado, Caugiay, Hanoi, Vietnam
| | - Radhika Dhakal
- Dept. of Pharmaceutical Sciences, Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA.
| | - Brian T Murphy
- Dept. of Pharmaceutical Sciences, Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA.
| |
Collapse
|
3
|
Efficacy and mechanism of actions of natural antimicrobial drugs. Pharmacol Ther 2020; 216:107671. [PMID: 32916205 DOI: 10.1016/j.pharmthera.2020.107671] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 02/07/2023]
Abstract
Microbial infections have significantly increased over the last decades, and the mortality rates remain unacceptably high. The emergence of new resistance patterns and the spread of new viruses challenge the eradication of infectious diseases. The declining efficacy of antimicrobial drugs has become a global public health problem. Natural products derived from natural sources, such as plants, animals, and microorganisms, have significant efficacy for the treatment of infectious diseases accompanied by less adverse effects, synergy, and ability to overcome drug resistance. As the Chinese female scientist Youyou Tu received the Nobel Prize for the antimalarial drug artemisinin, antimicrobial drugs developed from Traditional Chinese Medicine are expected to receive increasing attention again. This review summarizes the antimicrobial agents derived from natural products approved for nearly 20 years and describes their efficacy and mode of action. The aim of this unit is to review the current status of antimicrobial drugs from natural products in order to increase the value of natural products as a source of novel drug candidates for infectious diseases.
Collapse
|
4
|
Zhu P, Bu H, Tan S, Liu J, Yuan B, Dong G, Wang M, Jiang Y, Zhu H, Li H, Li Z, Jiang J, Wu M, Li R. A Novel Cochlioquinone Derivative, CoB1, Regulates Autophagy in Pseudomonas aeruginosa Infection through the PAK1/Akt1/mTOR Signaling Pathway. THE JOURNAL OF IMMUNOLOGY 2020; 205:1293-1305. [PMID: 32747503 DOI: 10.4049/jimmunol.1901346] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 07/08/2020] [Indexed: 12/31/2022]
Abstract
Owing to multiple antibiotic resistance, Pseudomonas aeruginosa causes the most intractable infections to human beings worldwide, thus exploring novel drugs to defend against this bacterium remains of great importance. In this study, we purified a novel cochlioquinone B derivative (CoB1) from Salvia miltiorrhiza endophytic Bipolaris sorokiniana and reveal its role in host defense against P. aeruginosa infection by activating cytoprotective autophagy in alveolar macrophages (AMs) both in vivo and in vitro. Using a P. aeruginosa infection model, we observed that CoB1-treated mice manifest weakened lung injury, reduced bacterial systemic dissemination, decreased mortality, and dampened inflammatory responses, compared with the wild type littermates. We demonstrate that CoB1-induced autophagy in mouse AMs is associated with decreased PAK1 expression via the ubiquitination-mediated degradation pathway. The inhibition of PAK1 decreases the phosphorylation level of Akt, blocks the Akt/mTOR signaling pathway, and promotes the release of ULK1/2-Atg13-FIP200 complex from mTOR to initiate autophagosome formation, resulting in increased bacterial clearance capacity. Together, our results provide a molecular basis for the use of CoB1 to regulate host immune responses against P. aeruginosa infection and indicate that CoB1 is a potential option for the treatment of infection diseases.
Collapse
Affiliation(s)
- Pengcheng Zhu
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, People's Republic of China
| | - Huimin Bu
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, People's Republic of China.,Department of Physiology, Xuzhou Medical College, Xuzhou 221004, People's Republic of China
| | - Shirui Tan
- Center for Life Sciences, School of Life Sciences, Yunnan University, Kunming 650500, China
| | - Jinjuan Liu
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, People's Republic of China
| | - Bo Yuan
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, People's Republic of China
| | - Guokai Dong
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, People's Republic of China
| | - Meng Wang
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, People's Republic of China
| | - Yuji Jiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, People's Republic of China
| | - Hong Zhu
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China
| | - Hui Li
- Department of Gastroenterology, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing Jiangsu 210028, People's Republic of China
| | - Zhenjun Li
- Suzhou Kowloon Hospital, School of Medicine, Shanghai Jiaotong University, Suzhou 215028, People's Republic of China; and
| | - Jihong Jiang
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, People's Republic of China;
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Rongpeng Li
- Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, People's Republic of China;
| |
Collapse
|
5
|
Wen Z, Yan C, Duan G, Li S, Wu FX, Wang J. A survey on predicting microbe-disease associations: biological data and computational methods. Brief Bioinform 2020; 22:5881365. [PMID: 34020541 DOI: 10.1093/bib/bbaa157] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/18/2020] [Accepted: 06/22/2020] [Indexed: 02/06/2023] Open
Abstract
Various microbes have proved to be closely related to the pathogenesis of human diseases. While many computational methods for predicting human microbe-disease associations (MDAs) have been developed, few systematic reviews on these methods have been reported. In this study, we provide a comprehensive overview of the existing methods. Firstly, we introduce the data used in existing MDA prediction methods. Secondly, we classify those methods into different categories by their nature and describe their algorithms and strategies in detail. Next, experimental evaluations are conducted on representative methods using different similarity data and calculation methods to compare their prediction performances. Based on the principles of computational methods and experimental results, we discuss the advantages and disadvantages of those methods and propose suggestions for the improvement of prediction performances. Considering the problems of the MDA prediction at present stage, we discuss future work from three perspectives including data, methods and formulations at the end.
Collapse
Affiliation(s)
- Zhongqi Wen
- Hunan Provincial Key Lab of Bioinformatics, School of Computer Science and Engineering at Central South University, Hunan, China
| | - Cheng Yan
- School of Computer Science and Engineering, Central South University, Changsha, Hunan, China
| | - Guihua Duan
- School of Computer Science and Engineering, Central South University
| | - Suning Li
- Hunan Provincial Key Lab of Bioinformatics, School of Computer Science and Engineering, Central South University, Changsha, Hunan, China
| | - Fang-Xiang Wu
- College of Engineering and the Department of Computer Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Jianxin Wang
- Hunan Provincial Key Lab of Bioinformatics, School of Computer Science and Engineering at Central South University, Hunan, China
| |
Collapse
|
6
|
Rajendran R, Abirami M, Santhini E, Dinesh Kirupha S, Vadodaria K. Evaluation of the bioactive properties of Alternanthera sessilis extract and development of sodium alginate – Alternanthera sessilis membrane for wound management. JOURNAL OF POLYMER ENGINEERING 2020. [DOI: 10.1515/polyeng-2019-0252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Many herbal/botanical medicines from plant sources are being used for therapeutic purpose. Alternanthera sessilis sp. plant leaves are known for their phytochemical constituents, which have potent antibacterial activity. In the present study, the properties of the A. sessilis sp. extract and the biocomposite membrane of A. sessilis sp. with sodium alginate were studied for their biomedical applications. Results showed that the A. sessilis ethanoic extract possessed high levels of antioxidant and antimicrobial activity and no cytotoxic effect under in vitro conditions. Similarly, the biocomposite membrane of alginate with the A. sessilis sp. ethanolic extract showed high antibacterial activity with hemocompatibility and swelling characteristics. Although the antioxidant, antimicrobial and cytotoxic effects of A. sessilis have been previously reported, this is the first report on the preparation of a biocomposite membrane with alginate using A. sessilis for biomedical applications.
Collapse
Affiliation(s)
- Ramaswamy Rajendran
- PG and Research Department of Microbiology, PSG College of Arts and Science (PSG-CAS) , Coimbatore 641014 , India
| | - Mariappan Abirami
- PG and Research Department of Microbiology, PSG College of Arts and Science (PSG-CAS) , Coimbatore 641014 , India
| | - Elango Santhini
- Centre of Excellence for Medical Textiles , South India Textile Research Association (SITRA) , Coimbatore 641014 , India
| | - Selvaraj Dinesh Kirupha
- Centre of Excellence for Medical Textiles , South India Textile Research Association (SITRA) , Coimbatore 641014 , India
| | - Ketankumar Vadodaria
- Centre of Excellence for Medical Textiles , South India Textile Research Association (SITRA) , Coimbatore 641014 , India
| |
Collapse
|
7
|
Ganley JG, Derbyshire ER. Linking Genes to Molecules in Eukaryotic Sources: An Endeavor to Expand Our Biosynthetic Repertoire. Molecules 2020; 25:E625. [PMID: 32023950 PMCID: PMC7036892 DOI: 10.3390/molecules25030625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 01/23/2020] [Accepted: 01/30/2020] [Indexed: 02/06/2023] Open
Abstract
The discovery of natural products continues to interest chemists and biologists for their utility in medicine as well as facilitating our understanding of signaling, pathogenesis, and evolution. Despite an attenuation in the discovery rate of new molecules, the current genomics and transcriptomics revolution has illuminated the untapped biosynthetic potential of many diverse organisms. Today, natural product discovery can be driven by biosynthetic gene cluster (BGC) analysis, which is capable of predicting enzymes that catalyze novel reactions and organisms that synthesize new chemical structures. This approach has been particularly effective in mining bacterial and fungal genomes where it has facilitated the discovery of new molecules, increased the understanding of metabolite assembly, and in some instances uncovered enzymes with intriguing synthetic utility. While relatively less is known about the biosynthetic potential of non-fungal eukaryotes, there is compelling evidence to suggest many encode biosynthetic enzymes that produce molecules with unique bioactivities. In this review, we highlight how the advances in genomics and transcriptomics have aided natural product discovery in sources from eukaryotic lineages. We summarize work that has successfully connected genes to previously identified molecules and how advancing these techniques can lead to genetics-guided discovery of novel chemical structures and reactions distributed throughout the tree of life. Ultimately, we discuss the advantage of increasing the known biosynthetic space to ease access to complex natural and non-natural small molecules.
Collapse
Affiliation(s)
- Jack G Ganley
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708-0346, USA
| | - Emily R Derbyshire
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708-0346, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, 213 Research Drive, Durham, NC 27710, USA
| |
Collapse
|
8
|
Costa MS, Clark CM, Ómarsdóttir S, Sanchez LM, Murphy BT. Minimizing Taxonomic and Natural Product Redundancy in Microbial Libraries Using MALDI-TOF MS and the Bioinformatics Pipeline IDBac. JOURNAL OF NATURAL PRODUCTS 2019; 82:2167-2173. [PMID: 31335140 PMCID: PMC7197193 DOI: 10.1021/acs.jnatprod.9b00168] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Libraries of microorganisms have been a cornerstone of drug discovery efforts since the mid-1950s, but strain duplication in some libraries has resulted in unwanted natural product redundancy. In the current study, we implemented a workflow that minimizes both the natural product overlap and the total number of bacterial isolates in a library. Using a collection expedition to Iceland as an example, we purified every distinct bacterial colony off isolation plates derived from 86 environmental samples. We employed our mass spectrometry (MS)-based IDBac workflow on these isolates to form groups of taxa based on protein MS fingerprints (3-15 kDa) and further distinguished taxa subgroups based on their degree of overlap within corresponding natural product spectra (0.2-2 kDa). This informed the decision to create a library of 301 isolates spanning 54 genera. This process required only 25 h of data acquisition and 2 h of analysis. In a separate experiment, we reduced the size of an existing library based on the degree of metabolic overlap observed in natural product MS spectra of bacterial colonies (from 833 to 233 isolates, a 72.0% size reduction). Overall, our pipeline allows for a significant reduction in costs associated with library generation and minimizes natural product redundancy entering into downstream biological screening efforts.
Collapse
Affiliation(s)
- Maria S Costa
- Faculty of Pharmaceutical Sciences , University of Iceland , Hagi, Hofsvallagata 53 , IS-107 Reykjavík , Iceland
- Department of Pharmaceutical Sciences, College of Pharmacy , University of Illinois at Chicago , 833 South Wood Street (MC 781), Room 539 , Chicago , Illinois 60607 , United States
| | - Chase M Clark
- Department of Pharmaceutical Sciences, College of Pharmacy , University of Illinois at Chicago , 833 South Wood Street (MC 781), Room 539 , Chicago , Illinois 60607 , United States
| | - Sesselja Ómarsdóttir
- Faculty of Pharmaceutical Sciences , University of Iceland , Hagi, Hofsvallagata 53 , IS-107 Reykjavík , Iceland
| | - Laura M Sanchez
- Department of Pharmaceutical Sciences, College of Pharmacy , University of Illinois at Chicago , 833 South Wood Street (MC 781), Room 539 , Chicago , Illinois 60607 , United States
| | - Brian T Murphy
- Department of Pharmaceutical Sciences, College of Pharmacy , University of Illinois at Chicago , 833 South Wood Street (MC 781), Room 539 , Chicago , Illinois 60607 , United States
| |
Collapse
|
9
|
Dehhaghi M, Mohammadipanah F, Guillemin GJ. Myxobacterial natural products: An under-valued source of products for drug discovery for neurological disorders. Neurotoxicology 2018; 66:195-203. [PMID: 29499217 DOI: 10.1016/j.neuro.2018.02.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 02/26/2018] [Accepted: 02/27/2018] [Indexed: 12/18/2022]
Abstract
Age-related disorders impose noticeable financial and emotional burdens on society. This impact is becoming more prevalent with the increasing incidence of neurodegenerative diseases and is causing critical concerns for treatment of patients worldwide. Parkinson's disease, Alzheimer's disease, multiple sclerosis and motor neuron disease are the most prevalent and the most expensive to treat neurodegenerative diseases globally. Therefore, exploring effective therapies to overcome these disorders is a necessity. Natural products and their derivatives have increasingly attracted attention in drug discovery programs that have identified microorganisms which produce a large range of metabolites with bioactive properties. Myxobacteria, a group of Gram-negative bacteria with large genome size, produce a wide range of secondary metabolites with significant chemical structures and a variety of biological effects. They are potent natural product producers. In this review paper, we attempt to overview some secondary metabolites synthesized by myxobacteria with neuroprotective activity through known mechanisms including production of polyunsaturated fatty acids, reduction of apoptosis, immunomodulation, stress reduction of endoplasmic reticulum, stabilization of microtubules, enzyme inhibition and serotonin receptor modulation.
Collapse
Affiliation(s)
- Mona Dehhaghi
- Department of Microbial Biotechnology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran; Neuropharmacology Group, Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia
| | - Fatemeh Mohammadipanah
- Department of Microbial Biotechnology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran.
| | - Gilles J Guillemin
- Neuropharmacology Group, Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia.
| |
Collapse
|
10
|
Liu M, Grkovic T, Liu X, Han J, Zhang L, Quinn RJ. A systems approach using OSMAC, Log P and NMR fingerprinting: An approach to novelty. Synth Syst Biotechnol 2017; 2:276-286. [PMID: 29552652 PMCID: PMC5851912 DOI: 10.1016/j.synbio.2017.10.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/03/2017] [Accepted: 10/09/2017] [Indexed: 01/23/2023] Open
Abstract
The growing number of sequenced microbial genomes has revealed a remarkably large number of secondary metabolite biosynthetic clusters for which the compounds are still unknown. The aim of the present work was to apply a strategy to detect newly induced natural products by cultivating microorganisms in different fermentation conditions. The metabolomic analysis of 4160 fractions generated from 13 actinomycetes under 32 different culture conditions was carried out by 1H NMR spectroscopy and multivariate analysis. The principal component analysis (PCA) of the 1H NMR spectra showed a clear discrimination between those samples within PC1 and PC2. The fractions with induced metabolites that are only produced under specific growth conditions was identified by PCA analysis. This method allows an efficient differentiation within a large dataset with only one fractionation step. This work demonstrates the potential of NMR spectroscopy in combination with metabolomic data analysis for the screening of large sets of fractions.
Collapse
Affiliation(s)
- Miaomiao Liu
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, 4111, Australia
| | - Tanja Grkovic
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, 4111, Australia
| | - Xueting Liu
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jianying Han
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,Graduate University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lixin Zhang
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ronald J Quinn
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, 4111, Australia
| |
Collapse
|
11
|
Natural products as probes in pharmaceutical research. J Ind Microbiol Biotechnol 2015; 43:249-60. [PMID: 26438431 DOI: 10.1007/s10295-015-1691-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/16/2015] [Indexed: 10/23/2022]
Abstract
From the start of the pharmaceutical research natural products played a key role in drug discovery and development. Over time many discoveries of fundamental new biology were triggered by the unique biological activity of natural products. Unprecedented chemical structures, novel chemotypes, often pave the way to investigate new biology and to explore new pathways and targets. This review summarizes the recent results in the area with a focus on research done in the laboratories of Novartis Institutes for BioMedical Research. We aim to put the technological advances in target identification techniques in the context to the current revival of phenotypic screening and the increasingly complex biological questions related to drug discovery.
Collapse
|
12
|
Antibacterial products of marine organisms. Appl Microbiol Biotechnol 2015; 99:4145-73. [PMID: 25874533 DOI: 10.1007/s00253-015-6553-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 03/17/2015] [Accepted: 03/19/2015] [Indexed: 10/23/2022]
Abstract
Marine organisms comprising microbes, plants, invertebrates, and vertebrates elaborate an impressive array of structurally diverse antimicrobial products ranging from small cyclic compounds to macromolecules such as proteins. Some of these biomolecules originate directly from marine animals while others arise from microbes associated with the animals. It is noteworthy that some of the biomolecules referred to above are structurally unique while others belong to known classes of compounds, peptides, and proteins. Some of the antibacterial agents are more active against Gram-positive bacteria while others have higher effectiveness on Gram-negative bacteria. Some are efficacious against both Gram-positive and Gram-negative bacteria and against drug-resistant strains as well. The mechanism of antibacterial action of a large number of the chemically identified antibacterial agents, possible synergism with currently used antibiotics, and the issue of possible toxicity on mammalian cells and tissues await elucidation. The structural characteristics pivotal to antibacterial activity have been ascertained in only a few studies. Demonstration of efficacy of the antibacterial agents in animal models of bacterial infection is highly desirable. Structural characterization of the active principles present in aqueous and organic extracts of marine organisms with reportedly antibacterial activity would be desirable.
Collapse
|
13
|
Martins A, Vieira H, Gaspar H, Santos S. Marketed marine natural products in the pharmaceutical and cosmeceutical industries: tips for success. Mar Drugs 2014; 12:1066-101. [PMID: 24549205 PMCID: PMC3944531 DOI: 10.3390/md12021066] [Citation(s) in RCA: 267] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 01/14/2014] [Accepted: 01/27/2014] [Indexed: 12/17/2022] Open
Abstract
The marine environment harbors a number of macro and micro organisms that have developed unique metabolic abilities to ensure their survival in diverse and hostile habitats, resulting in the biosynthesis of an array of secondary metabolites with specific activities. Several of these metabolites are high-value commercial products for the pharmaceutical and cosmeceutical industries. The aim of this review is to outline the paths of marine natural products discovery and development, with a special focus on the compounds that successfully reached the market and particularly looking at the approaches tackled by the pharmaceutical and cosmetic companies that succeeded in marketing those products. The main challenges faced during marine bioactives discovery and development programs were analyzed and grouped in three categories: biodiversity (accessibility to marine resources and efficient screening), supply and technical (sustainable production of the bioactives and knowledge of the mechanism of action) and market (processes, costs, partnerships and marketing). Tips to surpass these challenges are given in order to improve the market entry success rates of highly promising marine bioactives in the current pipelines, highlighting what can be learned from the successful and unsuccessful stories that can be applied to novel and/or ongoing marine natural products discovery and development programs.
Collapse
Affiliation(s)
- Ana Martins
- BIOALVO, S.A., Tec Labs Centro de Inovação, Campus da FCUL, Campo Grande, Lisboa 1749-016, Portugal.
| | - Helena Vieira
- BIOALVO, S.A., Tec Labs Centro de Inovação, Campus da FCUL, Campo Grande, Lisboa 1749-016, Portugal.
| | - Helena Gaspar
- Centro de Química e Bioquímica (CQB) and Departamento de Química e Bioquímica (DQB), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisboa 1749-016, Portugal.
| | - Susana Santos
- Centro de Química e Bioquímica (CQB) and Departamento de Química e Bioquímica (DQB), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisboa 1749-016, Portugal.
| |
Collapse
|
14
|
Nilar SH, Ma NL, Keller TH. The importance of molecular complexity in the design of screening libraries. J Comput Aided Mol Des 2013; 27:783-92. [DOI: 10.1007/s10822-013-9683-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Accepted: 10/07/2013] [Indexed: 01/20/2023]
|
15
|
Pelay-Gimeno M, Tulla-Puche J, Albericio F. "Head-to-side-chain" cyclodepsipeptides of marine origin. Mar Drugs 2013; 11:1693-717. [PMID: 23697952 PMCID: PMC3707169 DOI: 10.3390/md11051693] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 04/07/2013] [Accepted: 04/23/2013] [Indexed: 12/25/2022] Open
Abstract
Since the late 1980s, a large number of depsipeptides that contain a new topography, referred to as "head-to-side-chain" cyclodepsipeptides, have been isolated and characterized. These peptides present a unique structural arrangement that comprises a macrocyclic region closed through an ester bond between the C-terminus and a β-hydroxyl group, and terminated with a polyketide moiety or a more simple branched aliphatic acid. This structural pattern, the presence of unique and complex residues, and relevant bioactivity are the main features shared by all the members of this new class of depsipeptides, which are reviewed herein.
Collapse
Affiliation(s)
- Marta Pelay-Gimeno
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Baldiri Reixac 10, Barcelona 08028, Spain
| | - Judit Tulla-Puche
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Baldiri Reixac 10, Barcelona 08028, Spain
| | - Fernando Albericio
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Baldiri Reixac 10, Barcelona 08028, Spain
- Department of Organic Chemistry, University of Barcelona, Martí i Franqués 1-11, Barcelona 08028, Spain
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa
| |
Collapse
|
16
|
In vitro and in vivo activities of novel, semisynthetic thiopeptide inhibitors of bacterial elongation factor Tu. Antimicrob Agents Chemother 2011; 55:5277-83. [PMID: 21825297 DOI: 10.1128/aac.00582-11] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Recently, we identified aminothiazole derivatives of GE2270 A. These novel semisynthetic congeners, like GE2270 A, target the essential bacterial protein elongation factor Tu (EF-Tu). Medicinal chemistry optimization of lead molecules led to the identification of preclinical development candidates 1 and 2. These cycloalklycarboxylic acid derivatives show activity against difficult to treat Gram-positive pathogens and demonstrate increased aqueous solubility compared to GE2270 A. We describe here the in vitro and in vivo activities of compounds 1 and 2 compared to marketed antibiotics. Compounds 1 and 2 were potent against clinical isolates of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci (MIC(90) ≤ 0.25 μg/ml) but weaker against the streptococci (MIC(90) ≥ 4 μg/ml). Like GE2270 A, the derivatives inhibited bacterial protein synthesis and selected for spontaneous loss of susceptibility via mutations in the tuf gene, encoding EF-Tu. The mutants were not cross-resistant to other antibiotic classes. In a mouse systemic infection model, compounds 1 and 2 protected mice from lethal S. aureus infections with 50% effective doses (ED(50)) of 5.2 and 4.3 mg/kg, respectively. Similarly, compounds 1 and 2 protected mice from lethal systemic E. faecalis infections with ED(50) of 0.56 and 0.23 mg/kg, respectively. In summary, compounds 1 and 2 are active in vitro and in vivo activity against difficult-to-treat Gram-positive bacterial infections and represent a promising new class of antibacterials for use in human therapy.
Collapse
|
17
|
Freire-Moran L, Aronsson B, Manz C, Gyssens IC, So AD, Monnet DL, Cars O. Critical shortage of new antibiotics in development against multidrug-resistant bacteria-Time to react is now. Drug Resist Updat 2011; 14:118-24. [PMID: 21435939 DOI: 10.1016/j.drup.2011.02.003] [Citation(s) in RCA: 202] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 02/11/2011] [Accepted: 02/15/2011] [Indexed: 11/30/2022]
Abstract
Two commercial databases (Pharmaprojects and Adis Insight R&D) were queried for antibacterial agents in clinical development. Particular attention was given to antibacterial agents for systemic administration. For each agent, reviewers were requested to indicate whether its spectrum of activity covered a set of selected multidrug-resistant bacteria, and whether it had a new mechanism of action or a new target. In addition, PubMed was searched for antibacterial agents in development that appeared in review articles. Out of 90 agents that were considered to fulfil the inclusion criteria for the analysis, 66 were new active substances. Fifteen of these could be systemically administered and were assessed as acting via a new or possibly new mechanism of action or on a new or possibly new target. Out of these, 12 agents were assessed as having documented in vitro activity against antibiotic-resistant Gram-positive bacteria and only four had documented in vitro activity against antibiotic-resistant Gram-negative bacteria. Of these four, two acted on new or possibly new targets and, crucially, none acted via new mechanisms of action. There is an urgent need to address the lack of effective treatments to meet the increasing public health burden caused by multidrug-resistant bacteria, in particular against Gram-negative bacteria.
Collapse
|
18
|
Abstract
The discovery of novel small-molecule antibacterial drugs has been stalled for many years. The purpose of this review is to underscore and illustrate those scientific problems unique to the discovery and optimization of novel antibacterial agents that have adversely affected the output of the effort. The major challenges fall into two areas: (i) proper target selection, particularly the necessity of pursuing molecular targets that are not prone to rapid resistance development, and (ii) improvement of chemical libraries to overcome limitations of diversity, especially that which is necessary to overcome barriers to bacterial entry and proclivity to be effluxed, especially in Gram-negative organisms. Failure to address these problems has led to a great deal of misdirected effort.
Collapse
Affiliation(s)
- Lynn L Silver
- LL Silver Consulting, LLC, 955 S. Springfield Ave., Unit C403, Springfield, NJ 07081, USA.
| |
Collapse
|
19
|
McCoy LS, Xie Y, Tor Y. Antibiotics that target protein synthesis. WILEY INTERDISCIPLINARY REVIEWS-RNA 2010; 2:209-32. [DOI: 10.1002/wrna.60] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
20
|
Nogueira RC, de Cerqueira HF, Soares MBP. Patenting bioactive molecules from biodiversity: the Brazilian experience. Expert Opin Ther Pat 2010; 20:145-57. [DOI: 10.1517/13543770903555221] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
21
|
Natural products in drug discovery: present status and perspectives. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 655:13-27. [PMID: 20047031 DOI: 10.1007/978-1-4419-1132-2_2] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Natural products and their derivatives have been and continue to be rich sources for drug discovery. However, natural products are not drugs. They are produce in nature and through biological assays they are identified as leads, which become candidates for drug development. More than 60% of the drugs that are in the market derive from natural sources. During the last two decades, research aimed at exploiting natural products as a resource has seriously declined. This is in part due to the development of new technologies such as combinatorial chemistry, metagenomics and high-throughput screening. However, the new drug discovery approaches did not fulfilled the initial expectations. This has lead to a renewed interest in natural products, determined by the urgent need for new drugs, in particular to fight against infections caused by multi-resistant pathogens.
Collapse
|
22
|
Shahat AA, El-Barouty G, Hassan RA, Hammouda FM, Abdel-Rahman FH, Saleh MA. Chemical composition and antimicrobial activities of the essential oil from the seeds of Enterolobium contortisiliquum (leguminosae). JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2008; 43:519-525. [PMID: 18665989 DOI: 10.1080/03601230802174714] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Seeds of Enterolobium contortisiliquum were subjected to steam distillation to obtain a light yellow essential oil in a yield of 3 ml/kg of seeds. The major components of the oil were identified using gas chromatography/mass spectrometry (GC-MS) and were furfural, limonene, linalool, estragole, carvone, and apiole with carvone representing more than 50% of the total composition. Antimicrobial activities of the essential oil were determined against four species of gram positive bacteria (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Micrococcus luteus) and two gram negative bacteria (Klebsiella pneumoniae, Serratia Marcescencs). The essential oil inhibited the growth of all tested bacteria but was most effective against the gram positive bacteria. Chemicals that are responsible for the antibacterial effect of the essential oil were determined using the bio-autography thin layer chromatography (TLC) technique. The active compounds responsible for the activity were found to be carvone and estragole.
Collapse
|
23
|
Abstract
The continued increase in antibiotic resistance among bacterial pathogens, coupled with a decrease in infectious disease research among pharmaceutical companies, has escalated the need for novel and effective antibacterial chemotherapies. While current agents have emerged almost exclusively from whole-cell screening of natural products and small molecules that cause microbial death, recent advances in target identification and assay development have resulted in a flood of target-driven drug discovery methods. Whether genome-based methodologies will yield new classes of agents that conventional methods have been unable to is yet to be seen. At the end of the day, perhaps a synergy between old and new approaches will harvest the next generation of antibacterial treatments.
Collapse
|
24
|
Butler MS. Natural products to drugs: natural product-derived compounds in clinical trials. Nat Prod Rep 2008; 25:475-516. [PMID: 18497896 DOI: 10.1039/b514294f] [Citation(s) in RCA: 510] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Natural product and natural product-derived compounds that are being evaluated in clinical trials or are in registration (as at 31st December 2007) have been reviewed, as well as natural product-derived compounds for which clinical trials have been halted or discontinued since 2005. Also discussed are natural product-derived drugs launched since 2005, new natural product templates and late-stage development candidates.
Collapse
Affiliation(s)
- Mark S Butler
- MerLion Pharmaceuticals, 1 Science Park Road, The Capricorn 05-01, Singapore Science Park II, Singapore 117528.
| |
Collapse
|
25
|
Georgiades SN, Clardy J. Synthetic libraries of tyrosine-derived bacterial metabolites. Bioorg Med Chem Lett 2007; 18:3117-21. [PMID: 17983747 DOI: 10.1016/j.bmcl.2007.10.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2007] [Accepted: 10/16/2007] [Indexed: 11/18/2022]
Abstract
The preparation of a collection of 131 small molecules, reminiscent of families of long chain N-acyl tyrosines, enamides and enol esters that have been isolated from heterologous expression of environmental DNA (eDNA) in Escherichia coli, is reported. The synthetic libraries of N-acyl tyrosines and their 3-keto counterparts were prepared via solid-phase routes, whereas the enamides and enol esters were synthesized in solution-phase.
Collapse
Affiliation(s)
- Savvas N Georgiades
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | | |
Collapse
|
26
|
von Nussbaum F, Brands M, Hinzen B, Weigand S, Häbich D. Antibacterial natural products in medicinal chemistry--exodus or revival? Angew Chem Int Ed Engl 2007; 45:5072-129. [PMID: 16881035 DOI: 10.1002/anie.200600350] [Citation(s) in RCA: 467] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
To create a drug, nature's blueprints often have to be improved through semisynthesis or total synthesis (chemical postevolution). Selected contributions from industrial and academic groups highlight the arduous but rewarding path from natural products to drugs. Principle modification types for natural products are discussed herein, such as decoration, substitution, and degradation. The biological, chemical, and socioeconomic environments of antibacterial research are dealt with in context. Natural products, many from soil organisms, have provided the majority of lead structures for marketed anti-infectives. Surprisingly, numerous "old" classes of antibacterial natural products have never been intensively explored by medicinal chemists. Nevertheless, research on antibacterial natural products is flagging. Apparently, the "old fashioned" natural products no longer fit into modern drug discovery. The handling of natural products is cumbersome, requiring nonstandardized workflows and extended timelines. Revisiting natural products with modern chemistry and target-finding tools from biology (reversed genomics) is one option for their revival.
Collapse
Affiliation(s)
- Franz von Nussbaum
- Bayer HealthCare AG, Medicinal Chemistry Europe, 42096 Wuppertal, Germany.
| | | | | | | | | |
Collapse
|
27
|
Lam KS. New aspects of natural products in drug discovery. Trends Microbiol 2007; 15:279-89. [PMID: 17433686 DOI: 10.1016/j.tim.2007.04.001] [Citation(s) in RCA: 330] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Revised: 03/26/2007] [Accepted: 04/02/2007] [Indexed: 11/20/2022]
Abstract
During the past 15 years, most large pharmaceutical companies have decreased the screening of natural products for drug discovery in favor of synthetic compound libraries. Main reasons for this include the incompatibility of natural product libraries with high-throughput screening and the marginal improvement in core technologies for natural product screening in the late 1980s and early 1990 s. Recently, the development of new technologies has revolutionized the screening of natural products. Applying these technologies compensates for the inherent limitations of natural products and offers a unique opportunity to re-establish natural products as a major source for drug discovery. Examples of these new advances and technologies are described in this review.
Collapse
Affiliation(s)
- Kin S Lam
- Nereus Pharmaceuticals Inc., 10480 Wateridge Circle, San Diego, CA 92121, USA.
| |
Collapse
|
28
|
Baker DD, Chu M, Oza U, Rajgarhia V. The value of natural products to future pharmaceutical discovery. Nat Prod Rep 2007; 24:1225-44. [PMID: 18033577 DOI: 10.1039/b602241n] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Natural products have provided considerable value to the pharmaceutical industry over the past half century. In particular, the therapeutic areas of infectious diseases and oncology have benefited from numerous drug classes derived from natural product sources. Unfortunately, pharmaceutical companies have significantly decreased activities in natural product discovery during the past several years. Biotechnology companies working in the fields of combinatorial biosynthesis, genetic engineering and metagenomic approaches to identify novel natural product lead molecules have had limited success. Despite what appears to be a slow death of natural product discovery research, many new and interesting molecules with biological activity have been published in the past few years. If natural product materials continue to be tested for desirable therapeutic activities, we believe that significant progress in identifying new antibiotics, oncology therapeutics and other useful medicines will be made.
Collapse
Affiliation(s)
- Dwight D Baker
- Cubist Pharmaceuticals, Inc., 65 Hayden Avenue, Lexington, Massachusetts 02421, USA.
| | | | | | | |
Collapse
|
29
|
Abstract
The availability of microbial genome sequences has ushered in the genomics era and has led to numerous technical advancements over the past decade. These advances have been both in the bioinformatics field that has integrated computer-based approaches with biology and in research methods in the laboratory. The advances have assisted scientists in their study of bacterial gene complements and the roles of their gene products in the bacterial life cycle. Assignment of genes as essential to the bacterial cell nominated them as potential targets for antibacterial drugs and spurred attempts to exploit this information and convert it into drugs. At present, these efforts have met with minimal success. There are several possible reasons for these disappointing results including choice of targets and screen designs, compound libraries chosen for screens, and decreased commitment to antibacterial drug discovery by many large pharmaceutical companies. Structure-based approaches could become very effective in the future as methodologies continue to improve.
Collapse
|
30
|
Cohen J, Cabanilla L, Sosnov J. Role of follow-on drugs and indications on the WHO Essential Drug List. J Clin Pharm Ther 2006; 31:585-92. [PMID: 17176363 DOI: 10.1111/j.1365-2710.2006.00777.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION The World Health Organization's Essential Drug List (EDL) contains first-in-class drugs and subsequent class entrants (follow-on drugs) deemed necessary to combat diseases prevalent throughout the world, with a special emphasis on developing nations. The EDL also includes originally approved and follow-on indications. There are opposing views regarding the value of follow-on drugs and indications. Critics suggest many follow-on drugs and indications offer little or no benefit to patients. Advocates counter that follow-on drugs offer advantages in terms of improved effectiveness, compliance and patient satisfaction. OBJECTIVE In order to inform this debate on the value of follow-on drugs and indications we examined the numbers of follow-on drugs on the EDL and the extent to which follow-on indications are recommended. METHODS We identified all 312 drugs on the 14th edition of the EDL, omitting 72 non-pharmaceutical entities. For the 240 pharmaceutical entities we ascertained whether the Food and Drug Administration (FDA) had approved them, and, if so, when each was approved. We chose a validated therapeutic classification system - the United States Pharmacopeia's Model Guidelines for Medicare formulary management - in order to distinguish first-in-class and follow-on drugs on the EDL. Specifically, we selected the formulary key drug type as our benchmark therapeutic class. We assigned each EDL drug to a formulary key drug type. We defined first-in-class drugs as the first in each formulary key drug type, and follow-on drugs as all other drugs in each formulary key drug type. We identified follow-on indications by comparing WHO-listed indications with the original approved indication(s) by the FDA. Finally, we examined the therapeutic rating (priority vs. standard) given by the FDA to follow-on drugs on the EDL. RESULTS Sixty-three per cent of the EDL drugs were follow-ons; 15% of the indications were follow-on indications. Fourteen drugs were listed in multiple WHO (sub) groupings; and 49% of follow-on drugs were given a priority rating by the FDA. CONCLUSIONS In light of the fact that the EDL only includes drugs and indications deemed essential, the large number of follow-on drugs, follow-on indications, and priority-rated follow-on drugs on the EDL suggest their importance. From a public policy perspective, it may prove counterproductive to erect hurdles that impede follow-on research and development.
Collapse
Affiliation(s)
- J Cohen
- Tufts Center for Study of Drug Development, Boston, MA 02111, USA.
| | | | | |
Collapse
|
31
|
von Nussbaum F, Brands M, Hinzen B, Weigand S, Häbich D. Antibakterielle Naturstoffe in der medizinischen Chemie – Exodus oder Renaissance? Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200600350] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|