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1.
Org Lett ; 23(8): 3162-3166, 2021 04 16.
Article in English | MEDLINE | ID: mdl-33826848

ABSTRACT

The sesquiterpene cyclases pentalenene synthase (PenA) and two Δ6-protoilludene synthases Omp6 and Omp7 convert a FPP ether into several new tetrahydrofurano terpenoids, one of which is also formed as the main product by the sesquiterpene cyclase BcBOT2. Thus, PenA, Omp6/7, and BcBOT2 follow closely related catalytic pathways and induce similar folding of their diphosphate substrates despite low levels of amino acid sequence similarity. Some of the new terpenoids show pronounced olfactoric properties.


Subject(s)
Carbon-Carbon Lyases/chemistry , Ether/chemistry , Isomerases/chemistry , Amino Acid Sequence , Molecular Structure , Sesquiterpenes/chemistry
2.
Org Lett ; 22(11): 4360-4365, 2020 06 05.
Article in English | MEDLINE | ID: mdl-32432889

ABSTRACT

New sesquiterpene backbones are accessible after biotransformation of presilphiperfolan-8ß-ol synthase (BcBOT2), a fungal sesquiterpene synthase, with non-natural farnesyldiphosphates in which methyl groups are shifted by one position toward the diphosphate terminus. One of the macrocycles formed, a new germacrene A derivative, undergoes a Cope rearrangement to iso-ß-elemene. Three of the new terpenoids show olfactoric properties that range from an intense peppery note to a citrus, ozone-like, and fruity scent.


Subject(s)
Carbon-Carbon Lyases/metabolism , Polyisoprenyl Phosphates/metabolism , Sesquiterpenes/metabolism , Carbon-Carbon Lyases/chemistry , Molecular Structure , Polyisoprenyl Phosphates/chemistry , Sesquiterpenes/chemistry , Substrate Specificity
3.
Nat Prod Rep ; 37(8): 1080-1097, 2020 08 01.
Article in English | MEDLINE | ID: mdl-32068211

ABSTRACT

Covering: up to 2019The reactions catalysed by terpene synthases belong to the most complex and fascinating cascade-type transformations in Nature. Although many accept only one natural terpene precursor and convert it with high selectivity into only one product, several of these remarkable biocatalysts were recently shown to have a surprising plasticity towards non-natural substrate analogues. For an easy access to the topic also for readers who are new to the field, this review will first briefly cover the principles of natural terpene biosynthesis. This is followed by a chapter that highlights purely chemical transformations mimicking terpene synthase catalysed reactions. Then, the main focus of this article will shed light on the recent advances of terpene synthase catalysed transformations of synthetic substrate analogues. As will be demonstrated, a simple conceptual approach extensively broadens the chemical space that can be reached with terpene synthases.


Subject(s)
Terpenes/chemistry , Alkyl and Aryl Transferases/antagonists & inhibitors , Alkyl and Aryl Transferases/chemistry , Catalysis , Enzyme Inhibitors/pharmacology , Molecular Structure , Substrate Specificity
4.
Angew Chem Int Ed Engl ; 57(36): 11802-11806, 2018 09 03.
Article in English | MEDLINE | ID: mdl-29953712

ABSTRACT

The substrate flexibility of eight purified sesquiterpene cyclases was evaluated using six new heteroatom-modified farnesyl pyrophosphates, and the formation of six new heteroatom-modified macrocyclic and tricyclic sesquiterpenoids is described. GC-O analysis revealed that tricyclic tetrahydrofuran exhibits an ethereal, peppery, and camphor-like olfactoric scent.

5.
Sci Rep ; 7(1): 3950, 2017 06 21.
Article in English | MEDLINE | ID: mdl-28638147

ABSTRACT

Controlled large-scale production of human pluripotent stem cells (hPSCs) is indispensable for their envisioned clinical translation. Aiming at advanced process development in suspension culture, the sensitivity of hPSC media to continuous peristaltic pump-based circulation, a well-established technology extensively used in hydraulically-driven bioreactors, was investigated. Unexpectedly, conditioning of low protein media (i.e. E8 and TeSR-E8) in a peristaltic pump circuit induced severe viability loss of hPSCs cultured as aggregates in suspension. Optical, biochemical, and cytological analyses of the media revealed that the applied circulation mode resulted in the reduction of the growth hormone insulin by precipitation of micro-sized particles. Notably, in contrast to insulin depletion, individual withdrawal of other medium protein components (i.e. bFGF, TGFß1 or transferrin) provoked minor reduction of hPSC viability, if any. Supplementation of the surfactant glycerol or the use of the insulin analogue Aspart did not overcome the issue of insulin precipitation. In contrast, the presence of bovine or human serum albumin (BSA or HSA, respectively) stabilized insulin rescuing its content, possibly by acting as molecular chaperone-like protein, ultimately supporting hPSC maintenance. This study highlights the potential and the requirement of media optimization for automated hPSC processing and has broad implications on media development and bioreactor-based technologies.


Subject(s)
Cell Culture Techniques/methods , Insulin/analysis , Pluripotent Stem Cells/physiology , Bioreactors , Cell Aggregation , Cell Survival , Culture Media, Conditioned , Humans
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