Pecologix Political Ecology Blotter » biomimicry

Natural Products As Sources of New Drugs over the 30 Years from 1981 to 2010

A. Cherson — Tue, 27 Mar 2012 16:55:35 +0000

This review is an updated and expanded version of the three prior reviews that were published in this journal in 1997, 2003, and 2007. In the case of all approved therapeutic agents, the time frame has been extended to cover the 30 years from January 1, 1981, to December 31, 2010, for all diseases worldwide, and from 1950 (earliest so far identified) to December 2010 for all approved antitumor drugs worldwide. We have continued to utilize our secondary subdivision of a “natural product mimic” or “NM” to join the original primary divisions and have added a new designation, “natural product botanical” or “NB”, to cover those botanical “defined mixtures” that have now been recognized as drug entities by the FDA and similar organizations. From the data presented, the utility of natural products as sources of novel structures, but not necessarily the final drug entity, is still alive and well. Thus, in the area of cancer, over the time frame from around the 1940s to date, of the 175 small molecules, 131, or 74.8%, are other than “S” (synthetic), with 85, or 48.6%, actually being either natural products or directly derived therefrom. In other areas, the influence of natural product structures is quite marked, with, as expected from prior information, the anti-infective area being dependent on natural products and their structures. Although combinatorial chemistry techniques have succeeded as methods of optimizing structures and have been used very successfully in the optimization of many recently approved agents, we are able to identify only one de novo combinatorial compound approved as a drug in this 30-year time frame. We wish to draw the attention of readers to the rapidly evolving recognition that a significant number of natural product drugs/leads are actually produced by microbes and/or microbial interactions with the “host from whence it was isolated”, and therefore we consider that this area of natural product research should be expanded significantly.

DOI: http://dx.doi.org/10.1021/np200906s

Rediscovered Native American remedy kills poxvirus

A. Cherson — Mon, 26 Mar 2012 23:33:25 +0000

Historical sources suggest that in the 1800s, when smallpox still posed a serious threat, the Micmac native Americans of Nova Scotia treated the disease using a botanical infusion derived from the insectivorous plant Sarracenia purpurea, a species of pitcher plant.Now, Jeffrey Langland at Arizona State University in Tempe, US, and colleagues have conducted in vitro experiments with the herbal extract and found it inhibits replication of the variola virus, the causative agent behind smallpox.

doi: http://dx.doi.org/10.1371/journal.pone.0032610

Optimization of hydrogen production by Rhodobacter sphaeroides

A. Cherson — Sun, 29 Jan 2012 15:29:25 +0000

Water samples collected from the Northern region of India were used for isolation of anoxygenic photosynthetic (purple non-sulfur) bacterial isolate. The isolate was grown in modified Sistrom’s media at pH 7.0 and characterized as new strain of Rhodobacter sphaeroides NMBL-01 by 16S rDNA sequencing analysis and used for current study. Effect of pH on growth kinetics of the bacteria showed maximum growth rate at pH 8.0 using malic acid as carbon source. The effect of C/N ratio (molar ratio of carbon to nitrogen) at 1.5, 5, 10, 13, 15, 20, 25, 30, 40, 50 and 80 using malate as carbon and glutamate/ammonium sulfate as nitrogen source on hydrogen production was investigated. The maximum hydrogen potential and hydrogen production rate were 2000 ± 45 cm³ m⁻³ and 11.8 cm³ m⁻³ h⁻¹, respectively, at C/N 13 using glutamate (1.7 mmol m⁻³) as nitrogen source and malate (3 g m⁻³) as carbon source with 66.5% malate conversion efficiency at initial medium pH 8.0. Further optimization of hydrogen production was performed keeping nitrogen source, glutamate (1.7 mmol m⁻³) constant with variable concentration of different carbon sources (succinate, butyrate, malate and acetate). The bacteria produced maximum hydrogen using malic acid at a concentration of 4 g m⁻³ as source of carbon, i.e. 2755 ± 32 cm³ m⁻³ with 68.3% conversion efficiency followed by succinate (1980 ± 25 cm³ m⁻³ with 58% conversion), butyrate (1400 ± 12 cm³ m⁻³ with 14.1% conversion) and acetate (650 ± 12 cm³ m⁻³ with 23.2% conversion).

DOI: http://dx.doi.org/10.1016/j.biombioe.2011.12.005

Incorporating microorganisms into polymer layers provides bioinspired functional living materials

A. Cherson — Mon, 09 Jan 2012 01:39:01 +0000

Artificial two-dimensional biological habitats were prepared from porous polymer layers and inoculated with the fungus Penicillium roqueforti to provide a living material. Such composites of classical industrial ingredients and living microorganisms can provide a novel form of functional or smart materials with capability for evolutionary adaptation. This allows realization of most complex responses to environmental stimuli. As a conceptual design, we prepared a material surface with self-cleaning capability when subjected to standardized food spill. Fungal growth and reproduction were observed in between two specifically adapted polymer layers. Gas exchange for breathing and transport of nutrient through a nano-porous top layer allowed selective intake of food whilst limiting the microorganism to dwell exclusively in between a confined, well-enclosed area of the material. We demonstrated a design of such living materials and showed both active (eating) and waiting (dormant, hibernation) states with additional recovery for reinitiation of a new active state by observing the metabolic activity over two full nutrition cycles of the living material (active, hibernation, reactivation). This novel class of living materials can be expected to provide nonclassical solutions in consumer goods such as packaging, indoor surfaces, and in biotechnology.

doi: http://dx.doi.org/10.1073/pnas.1115381109

Modern Natural Products Drug Discovery and Its Relevance to Biodiversity Conservation

A. Cherson — Thu, 17 Nov 2011 01:12:15 +0000

Natural products continue to provide a diverse and unique source of bioactive lead compounds for drug discovery, but maintaining their continued eminence as source compounds is challenging in the face of the changing face of the pharmaceutical industry and the changing nature of biodiversity prospecting brought about by the Convention on Biological Diversity. This review provides an overview of some of these challenges and suggests ways in which they can be addressed so that natural products research can remain a viable and productive route to drug discovery. Results from International Cooperative Biodiversity Groups (ICBGs) working in Madagascar, Panama, and Suriname are used as examples of what can be achieved when biodiversity conservation is linked to drug discovery.

DOI: http://dx.doi.org/10.1021/np100550t

Natural Products as Sources of New Drugs over the Last 25 Years

A. Cherson — Thu, 17 Nov 2011 01:08:23 +0000

From the data presented, the utility of natural products as sources of novel structures, but not necessarily the final drug entity, is still alive and well. Thus, in the area of cancer, over the time frame from around the 1940s to date, of the 155 small molecules, 73% are other than “S” (synthetic), with 47% actually being either natural products or directly derived therefrom. In other areas, the influence of natural product structures is quite marked, with, as expected from prior information, the antiinfective area being dependent on natural products and their structures. Although combinatorial chemistry techniques have succeeded as methods of optimizing structures and have, in fact, been used in the optimization of many recently approved agents, we are able to identify only one de novo combinatorial compound approved as a drug in this 25 plus year time frame. We wish to draw the attention of readers to the rapidly evolving recognition that a significant number of natural product drugs/leads are actually produced by microbes and/or microbial interactions with the “host from whence it was isolated”, and therefore we consider that this area of natural product research should be expanded significantly.

DOI: http://dx.doi.org/10.1021/np068054v