Publications by authors named "Christopher Leber"

Kavaratamide A (), a new linear lipodepsipeptide possessing an unusual isopropyl--methylpyrrolinone moiety, was discovered from the tropical marine filamentous cyanobacterium collected from Kavaratti, India. A comparative chemogeographic analysis of . collected from six different geographical regions led to the prioritized isolation of this metabolite from India as distinctive among our data sets.

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Computational approaches such as genome and metabolome mining are becoming essential to natural products (NPs) research. Consequently, a need exists for an automated structure-type classification system to handle the massive amounts of data appearing for NP structures. An ideal semantic ontology for the classification of NPs should go beyond the simple presence/absence of chemical substructures, but also include the taxonomy of the producing organism, the nature of the biosynthetic pathway, and/or their biological properties.

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Cyanobacteria have multifaceted ecological roles on coral reefs. , a chemically rich filamentous cyanobacterium, has been characterized as a pathogenic organism with an unusual ability to overgrow gorgonian corals, but little has been done to study its general growth habits or its unique association with the snapping shrimp . Quantitative benthic surveys, and field and photographic observations were utilized to develop a better understanding of the ecology of these species, while growth experiments and nutrient analysis were performed to examine how this cyanobacterium may be benefiting from its shrimp symbiont.

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Article Synopsis
  • The tropical marine cyanobacterium is found in the Indian and Western Tropical Pacific Oceans, known for producing unique and biologically active natural products.
  • Advanced computational methods, including the ORCA pipeline, were used to analyze samples and identify regional variations in natural product production.
  • The study identified doscadenamide A, a natural product linked to a larger family of compounds, showing potential as an anti-cancer agent when used with lipopolysaccharide (LPS), highlighting the importance of chemogeographic patterns in natural product discovery.
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Article Synopsis
  • The text discusses a highly studied soft coral known for producing a variety of natural products, specifically cembrane diterpenoids, which have been observed to have inconsistent chemical compositions over 50 years.
  • Recent research has found that this coral is not just one species, but a complex of at least seven genetically distinct species that are hard to differentiate with traditional methods.
  • The study involved collecting samples from Palau and performing both molecular and chemical analyses, revealing that the previously observed chemical variation might be due to differences between these cryptic species rather than within a single species.
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The cars we drive, the homes we live in, the restaurants we visit, and the laboratories and offices we work in are all a part of the modern human habitat. Remarkably, little is known about the diversity of chemicals present in these environments and to what degree molecules from our bodies influence the built environment that surrounds us and vice versa. We therefore set out to visualize the chemical diversity of five built human habitats together with their occupants, to provide a snapshot of the various molecules to which humans are exposed on a daily basis.

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Biologically derived fatty acids have gained tremendous interest as an alternative to petroleum-derived fuels and chemical precursors. We previously demonstrated the synthesis of short chain fatty acids in Saccharomyces cerevisiae by introduction of the Homo sapiens fatty acid synthase (hFAS) with heterologous phosphopantetheine transferases and heterologous thioesterases. In this study, short chain fatty acid production was improved by combining a variety of novel enzyme and metabolic engineering strategies.

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The native yeast type I fatty acid synthase (FAS) is a complex, rigid enzyme, and challenging to engineer for the production of medium- or short-chain fatty acids. Introduction of a type II FAS is a promising alternative as it allows expression control for each discrete enzyme and the addition of heterologous thioesterases. In this study, the native Saccharomyces cerevisiae FAS was functionally replaced by the Escherichia coli type II FAS (eFAS) system.

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The production of fuels and chemicals from biorenewable resources is important to alleviate the environmental concerns, costs, and foreign dependency associated with the use of petroleum feedstock. Fatty acids are attractive biomolecules due to the flexibility of their iterative biosynthetic pathway, high energy content, and suitability for conversion into other secondary chemicals. Free fatty acids (FFAs) that can be secreted from the cell are particularly appealing due to their lower harvest costs and straightforward conversion into a broad range of biofuel and biochemical products.

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Carbon feedstocks from fossilized sources are being rapidly depleted due to rising demand for industrial and commercial applications. Many petroleum-derived chemicals can be directly or functionally substituted with chemicals derived from renewable feedstocks. Several short chain organic acids may fulfill this role using their functional groups as a target for chemical catalysis.

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