China
Africa
Explore chapters and articles related to this topic
On Biocatalysis as Resourceful Methodology for Complex Syntheses: Selective Catalysis, Cascades and Biosynthesis
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Andreas Sebastian Klein, Thomas Classen, Jörg Pietruszka
Especially due to the development of organic chemistry from the second half of the 20th century onwards, the total synthesis of natural products forms the basis for the provision of bioactive compounds (vice versa, the demand for natural products formed the basis for the evolution of organic chemistry to this day). Through the continuous development of new reactions, catalysts and reagents, multi-component and domino reactions and stereospecific reactions—not least through the aforementioned use of biocatalysts—the most complex structures can currently be produced. A major advantage of total synthesis is certainly the control of each step in the synthesis, which simplifies the provision of derivatives. However, with increasing complexity of the molecules, the number of synthetic steps usually also increases, which inevitably reduces the total yield. It is precisely this argument that makes total synthesis for an industrial approach in a number of cases unattractive, so that a critical economic consideration is necessary in comparison with the potential of a natural product.
Synthesis Plan Analysis
Published in John Andraos, Synthesis Green Metrics, 2018
A general term used by classically trained synthetic organic chemists to describe the sequence of strategic steps employed in the total synthesis of a given target molecule. This entails (a) the type of reactions employed that can be in any one of the following broad categories: additions, substitutions, eliminations, rearrangements, redox reactions, or multi-component; (b) the number of those reactions that are target bond forming (construction steps) and those that are sacrificial steps (concession steps); and (c) whether the synthesis plan follows a linear or convergent trajectory. Tools often used to strategize how a given target molecule can be assembled from smaller molecules are retrosynthetic analysis and the large database of known named organic reactions. Example 2.2644Suggest a linear and a convergent plan for the target molecule shown and compare their atom economy performances. Show by-products in each reaction step.
Optimization of fermentation medium and conditions for enhancing valinomycin production by Streptomyces sp. ZJUT-IFE-354
Published in Preparative Biochemistry & Biotechnology, 2023
Dong Zhang, Yingling Bao, Zhi Ma, Jiawei Zhou, Hanchi Chen, Yuele Lu, Linjiang Zhu, Xiaolong Chen
Though total synthesis of valinomycin has been reported,[5,12–14] the pathways of chemical synthesis have disadvantages, such as complexity, low efficiency and yield, many by-products, and so on.[5] Moreover, valinomycin can be generated by microorganisms.[1,2,15–17] It was revealed that valinomycin is biosynthesized by a tetramodular valinomycin synthetase, which was coded by two large NRPS genes vlm1 (10,287 bp) and vlm2 (7968 bp), and open reading frames[2,15,16] It has been demonstrated that α-ketoisovalerate (α-Kiv), pyruvate, and L-valine were basic precursors of valinomycin biosynthesis.[18–20] The production levels of valinomycin have been summarized.[1,21] According to Sharma,[22] under optimal fermentation and elicitation conditions, the maximum valinomycin production by Streptomyces lavendulae ACR-DA1 was 84 mg/L.