Biomimetic synthesis of ordered silica structures mediated by block copolypeptides

Nature ◽  
2000 ◽  
Vol 403 (6767) ◽  
pp. 289-292 ◽  
Author(s):  
Jennifer N. Cha ◽  
Galen D. Stucky ◽  
Daniel E. Morse ◽  
Timothy J. Deming
Keyword(s):  
Biomimetic Synthesis ◽  
Block Copolypeptides

Learning From Biological Systems: Novel Routes to Biomimetic Synthesis of Ordered Silica Structures

1999 ◽  
Vol 599 ◽  
Author(s):  
Jennifer N. Chal ◽  
Katsuhiko Shimizu ◽  
Yan Zhou ◽  
Sean C. Christiansen ◽  
Bradley F. Chmelka ◽  
...  
Keyword(s):  
Structural Control ◽  
Catalytic Mechanism ◽  
Ambient Pressure ◽  
Biological Systems ◽  
Dry Weight ◽  
Biomimetic Synthesis ◽  
Skeletal System ◽  
Structural Determinants ◽  
Axial Filament ◽  
Block Copolypeptides

AbstractBiological systems have evolved mechanisms that precisely control inorganic structures on both the micro- and nanoscale, operating at ambient pressures and temperatures. In both the calcium carbonate, calcium phosphate and silicon dioxide utilizing organisms, proteins and polysaccharides have been found to play integral roles in the organization of these biominerals[1–3]. The organic constituents generally have been thought to act as direct templates or modulators for the deposition of the particular mineral. We have explored the synthesis and structural control of silica by the marine sponge, Tethya aurantia. Needles of amorphous silica comprise the skeletal system of this organism, representing 75% of the dry weight of the organism. These glassy needles, called spicules, are 2 mm in length and 30 μn in width[4,5]. We have characterized the structure, genetics and functions of the proteins that form an occluded axial filament within each silica spicule. Based on our discovery, a unique structure-directing catalytic mechanism exhibited by these protein filaments, and the structural determinants responsible for the catalytic activity, we have designed novel block copolypeptides that catalyze and spatially direct he condensation of silicon alkoxides to form organized silica structures ranging from transparent spheres to lath-like structures at ambient pressure, low temperature and neutral pH.

Synthesis and Reactivity of Precolibactin 886

2019 ◽  
Author(s):  
Seth Herzon ◽  
Alan R. Healy ◽  
kevin wernke ◽  
Chung Sub Kim ◽  
Nicholas Lees ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Gene Cluster ◽  
Amino Alcohol ◽  
Biomimetic Synthesis ◽  
Cross Linking ◽  
E Coli ◽  
Hplc Purification ◽  
Structural Assignment ◽  
Biosynthetic Precursor ◽  
Double Oxidation

<div>The clb gene cluster encodes the biosynthesis of metabolites known as precolibactins and colibactins. The clb pathway is found in gut commensal E. coli, and clb metabolites are thought to initiate colorectal cancer via DNA cross-linking. Precolibactin 886 (1) is one of the most complex isolated clb metabolites; it contains a 15-atom macrocycle and an unusual 5-hydroxy-3-oxazoline ring. Here we report confirmation of the structural assignment via a biomimetic synthesis of precolibactin 886 (1) proceeding through the amino alcohol 9. Double oxidation of 9 afforded the unstable α-ketoimine 2 which underwent macrocyclization to precolibactin 886 (1) upon HPLC purification (3% from 9). Studies of the putative precolibactin 886 (1) biosynthetic precursor 2, the model α-ketoimine 25, and the α-dicarbonyl 26 revealed that these compounds are susceptible to nucleophilic rupture of the C36–C37 bond. Moreover, cleavage of 2 produces other known clb metabolites or biosynthetic intermediates. This unexpected reactivity explains the difficulties in isolating full clb metabolites and accounts for the structure of a recently identified colibactin–adenine adduct. The colibactin peptidase ClbP deacylates synthetic precolibactin 886 (1) to form a non-genotoxic pyridone, suggesting precolibactin 886 (1) lies off-path of the major biosynthetic route.</div>

Biomimetic synthesis and anti-inflammatory evaluation of violacin A analogues

2021 ◽  
pp. 104898
Author(s):  
Wenxi Wu ◽  
Yu Mu ◽  
Bo Liu ◽  
Zixuan Wang ◽  
Peipei Guan ◽  
...  
Keyword(s):  
Biomimetic Synthesis ◽  
Anti Inflammatory

Biomimetic Synthesis of Meroterpenoids by Dearomatization‐Driven Polycyclization

2019 ◽  
Vol 131 (45) ◽  
pp. 16287-16292 ◽  
Author(s):  
Zachary Powers ◽  
Adam Scharf ◽  
Andrea Cheng ◽  
Feng Yang ◽  
Martin Himmelbauer ◽  
...  
Keyword(s):  
Biomimetic Synthesis
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