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Greg O. Buchanan

Bio: Greg O. Buchanan is an academic researcher from Scripps Research Institute. The author has contributed to research in topics: Salinispora tropica & Salinosporamide A. The author has an hindex of 5, co-authored 6 publications receiving 1241 citations. Previous affiliations of Greg O. Buchanan include University of California, San Diego.

Papers
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Journal ArticleDOI
TL;DR: The ocean is an overlooked habitat from which to isolate important microorganisms, and the rate of discovery of new biologically active compounds from common soil actino-mycetes has been falling.
Abstract: thus the discovery of a major new group of thesebacteria in marine sediments suggests that the ocean repre-sents an overlooked habitat from which to isolate theseimportant microorganisms. Given thatthe rate of discovery ofnew biologically active compounds from common soil actino-mycetes has been falling,

962 citations

Journal ArticleDOI
TL;DR: Data from extensive testing against the human colon carcinoma HCT-116 and the 60-cell-line panel at the NCI indicate that the chloroethyl moiety plays a major role in the enhanced activity of 1.
Abstract: An extensive study of the secondary metabolites produced by the obligate marine actinomycete Salinispora tropica (strain CNB-392), the producing microbe of the potent proteasome inhibitor salinosporamide A (1), has led to the isolation of seven related gamma-lactams. The most important of these compounds were salinosporamide B (3), which is the deschloro-analogue of 1, and salinosporamide C (4), which is a decarboxylated pyrrole analogue. New SAR data for all eight compounds, derived from extensive testing against the human colon carcinoma HCT-116 and the 60-cell-line panel at the NCI, indicate that the chloroethyl moiety plays a major role in the enhanced activity of 1.

171 citations

Journal ArticleDOI
TL;DR: Analysis of the fermentation broth of a strain of the marine actinomycete Salinispora tropica has led to the isolation of two unprecedented macrolides, sporolides A and B, which were elucidated using a combination of NMR spectroscopy and X-ray crystallography.

136 citations

Journal ArticleDOI
TL;DR: The discovery of a major new group of actino-mycetes in marine sediments suggests that the ocean repre-sents an overlooked habitat from which to isolate theseimportant microorganisms as mentioned in this paper.
Abstract: thus the discovery of a major new group of thesebacteria in marine sediments suggests that the ocean repre-sents an overlooked habitat from which to isolate theseimportant microorganisms. Given thatthe rate of discovery ofnew biologically active compounds from common soil actino-mycetes has been falling,

46 citations

Journal ArticleDOI
TL;DR: In this article, an extensive study of the secondary metabolites produced by the obligate marine actinomycete Salinispora tropica (strain CNB-392), the producing microbe of the potent proteasome inhibitor salinosporamide A (1), has led to the isolation of seven related gamma-lactams.
Abstract: An extensive study of the secondary metabolites produced by the obligate marine actinomycete Salinispora tropica (strain CNB-392), the producing microbe of the potent proteasome inhibitor salinosporamide A (1), has led to the isolation of seven related gamma-lactams. The most important of these compounds were salinosporamide B (3), which is the deschloro-analogue of 1, and salinosporamide C (4), which is a decarboxylated pyrrole analogue. New SAR data for all eight compounds, derived from extensive testing against the human colon carcinoma HCT-116 and the 60-cell-line panel at the NCI, indicate that the chloroethyl moiety plays a major role in the enhanced activity of 1.

27 citations


Cited by
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Journal ArticleDOI
TL;DR: This review covers the literature published in 2014 for marine natural products, with 1116 citations referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms.

4,649 citations

Journal ArticleDOI
TL;DR: This review traces natural products drug discovery, outlining important drugs from natural sources that revolutionized treatment of serious diseases and effective drug development depends on multidisciplinary collaborations.

2,272 citations

Journal ArticleDOI
TL;DR: A critical appraisal of different synthetic approaches to Cu and Cu-based nanoparticles and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications in catalysis.
Abstract: The applications of copper (Cu) and Cu-based nanoparticles, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis. The possible modification of the chemical and physical properties of these nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical treatments has been largely responsible for the rapid growth of interest in these nanomaterials and their applications in catalysis. In addition, the design and development of novel support and/or multimetallic systems (e.g., alloys, etc.) has also made significant contributions to the field. In this comprehensive review, we report different synthetic approaches to Cu and Cu-based nanoparticles (metallic copper, copper oxides, and hybrid copper nanostructures) and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications i...

1,823 citations

Journal ArticleDOI
TL;DR: Strategies to re-establish viable platforms for antibiotic discovery include investigating untapped natural product sources such as uncultured bacteria, establishing rules of compound penetration to enable the development of synthetic antibiotics, developing species-specific antibiotics and identifying prodrugs that have the potential to eradicate dormant persisters, which are often responsible for hard-to-treat infections.
Abstract: The spread of resistant bacteria, leading to untreatable infections, is a major public health threat but the pace of antibiotic discovery to combat these pathogens has slowed down. Most antibiotics were originally isolated by screening soil-derived actinomycetes during the golden era of antibiotic discovery in the 1940s to 1960s. However, diminishing returns from this discovery platform led to its collapse, and efforts to create a new platform based on target-focused screening of large libraries of synthetic compounds failed, in part owing to the lack of penetration of such compounds through the bacterial envelope. This article considers strategies to re-establish viable platforms for antibiotic discovery. These include investigating untapped natural product sources such as uncultured bacteria, establishing rules of compound penetration to enable the development of synthetic antibiotics, developing species-specific antibiotics and identifying prodrugs that have the potential to eradicate dormant persisters, which are often responsible for hard-to-treat infections.

1,221 citations

Journal ArticleDOI
TL;DR: Actinobacteria are Gram-positive bacteria with high G+C DNA content that constitute one of the largest bacterial phyla, and they are ubiquitously distributed in both aquatic and terrestrial ecosystems.
Abstract: Actinobacteria are Gram-positive bacteria with high G+C DNA content that constitute one of the largest bacterial phyla, and they are ubiquitously distributed in both aquatic and terrestrial ecosystems. Many Actinobacteria have a mycelial lifestyle and undergo complex morphological differentiation. They also have an extensive secondary metabolism and produce about two-thirds of all naturally derived antibiotics in current clinical use, as well as many anticancer, anthelmintic, and antifungal compounds. Consequently, these bacteria are of major importance for biotechnology, medicine, and agriculture. Actinobacteria play diverse roles in their associations with various higher organisms, since their members have adopted different lifestyles, and the phylum includes pathogens (notably, species of Corynebacterium, Mycobacterium, Nocardia, Propionibacterium, and Tropheryma), soil inhabitants (e.g., Micromonospora and Streptomyces species), plant commensals (e.g., Frankia spp.), and gastrointestinal commensals (Bifidobacterium spp.). Actinobacteria also play an important role as symbionts and as pathogens in plant-associated microbial communities. This review presents an update on the biology of this important bacterial phylum.

1,199 citations