Glutamate synthesis via photoreduction of NADP+ by photostable chlorophyllide coupled with polyethylene-glycol

Facile production of chlorophyllides using recombinant CrCLH1 and their cytotoxicity towards multidrug resistant breast cancer cell lines

The purity of chlorophylls plays one of the key role for the production of chlorophyllides. We have designed a facile method for chlorophyll purification by twice solvent extraction. Twice extraction causes the loss of chlorophylls, but the purity of total chlorophylls can be enhanced 182%. Then, the purified chlorophylls can be converted to relatively pure chlorophyllides facilely. The results show that higher purity of chlorophyllides could be obtained when purified chlorophylls (ethanol-hexane extract) was used as starting materials than that of crude chlorophylls (ethanol-only extract). In biocompatibility test, the results showed that the prepared chlorophyllides can be applied as biomaterials. When the prepared chlorophyllides were applied to anticancer tests, they were active both in MCF7 and MDA-MB-231 (multidrug resistant breast cancer cells) cell lines. In addition, the results suggested that the prepared chlorophyllides could be a potential candidate of combination therapy with doxorubicin to breast cancers.

A Photoenzymatic NADH Regeneration System

A photoenzymatic NADH regeneration system was established. The combination of deazariboflavin as a photocatalyst with putidaredoxin reductase enabled the selective reduction of NAD+ into the enzyme-active 1,4-NADH to promote an alcohol dehydrogenase catalysed stereospecific reduction reaction. The catalytic turnover of all the reaction components was demonstrated. Factors influencing the efficiency of the overall system were identified.

Artificial Photosynthesis: Hybrid Systems

Oxidoreductases are promising catalysts for organic synthesis. To sustain their catalytic cycles they require efficient supply with redox equivalents. Today classical biomimetic approaches utilizing natural electron supply chains prevail but artificial regeneration approaches bear the promise of simpler and more robust reaction schemes. Utilizing visible light can accelerate such artificial electron transport chains and even enable thermodynamically unfeasible reactions such as the use of water as reductant.This contribution critically summarizes the current state of the art in photoredoxbiocatalysis (i.e. light-driven biocatalytic oxidation and reduction reactions).

How green is green chemistry? Chlorophylls as a bioresource from biorefineries and their commercial potential in medicine and photovoltaics

Chlorophylls are the natural green pigments par excellence and offer potential as therapeutics and in energy generation. This perspective outlines the state-of-the-art, their possible applications and indicates future directions in the context of green chemistry and their production from biorefineries.

New platform for cytochrome p450 reaction combining in situ immobilization on biopolymer

We describe an efficienct chemical conversion platform with in situ immobilization of P450-BM3 on poly(3-hydroxybutyrate) granules. Through fusion with phasin, P450-BM3 is easily immobilized on poly(3-hydroxybutyrate) granules in Escherichia coli. In our work, the immobilized P450 exhibited higher stability and catalytic activity compared to free P450 against changes of pH, temperature, and concentrations of urea and ions. Through quick recovery of immobilized enzyme, the P450-P(3HB) complex successfully catalyzed an O-dealkylation reaction several times with maintained activity. Using the robust P450-P(3HB) complex, we performed a P450-catalyzed reaction on a preparative reactor scale (100 mL) and high-level production (12.3 μM) of 7-hydroxycoumarine from 7-ethoxycoumarin could be achieved.

Uniform graphitic carbon nitride nanorod for efficient photocatalytic hydrogen evolution and sustained photoenzymatic catalysis

Uniform graphitic carbon nitride nanorods (CNR) were facilely obtained by a morphology-preserving strategy by templating a chiral mesostructured silica nanorod. The hexagonal mesostructured pore structures of one-dimensional silica nanorods can provide nanoconfinement space for carbon nitride condensation to perfect layered structures. CNR demonstrated excellent photocatalytic capability in generating hydrogen from water even with a small specific surface area, compared with its mesoporous counterpart. For further application demonstration, the CNR was used for photocatalytic regeneration of NAD(+) to NADH, the biological form of hydrogen. The in situ NADH regeneration system was further coupled with l-glutamate dehydrogenase for sustainable generation of l-glutamate from α-ketoglutarate. The high yield and high efficiency obtained here point a high-throughput and sustainable way for practical enzymatic applications.

Photoenzymatic synthesis through sustainable NADH regeneration by SiO2-supported quantum dots

Sustainable photochemical NADH regeneration and redox-enzymatic synthesis are accomplished by using CdS nanocrystals grown on the surface of SiO(2) beads. CdS nanocrystals grown on SiO(2) beads worked efficiently as a visible-light absorbing photocatalyst for in situ NADH regeneration with high catalytic activity and minimal loss of activity despite repeated uses.

Towards novel processes for the fine-chemical and pharmaceutical industries

In response to the need in the pharmaceutical industry for more complex, chiral molecules, fine-chemical companies are embracing new manufacturing technologies to produce compounds of these specifications. In particular, recent developments in biocatalysis combined with novel process engineering are providing improved methods for the production of valuable chemical intermediates.