Hydroxynitrile lyases (HNLs) from Prunus amygdalus (PaHNL), Sorghum bicolor (SbHNL), Manihot esculenta (MeHNL) and Hevea brasiliensis (HbHNL) are excellent biocatalysts for the preparation of optically active cyanohydrins. (R)as well as (S)-cyanohydrins are obtained in high optical and chemical yields. The synthetic potential of the now easily available optically pure cyanohydrins is demonstrat...

Two new types of signaling compounds have been discovered in wildfire smoke due to their ability to stimulate seed germination. The first discovered were karrikins, which share some structural similarity with the strigolactone class of plant hormones, and both signal through a common F-box protein. However, karrikins and strigolactones operate through otherwise distinct signaling pathways, each...

In this study, β-cyclodextrin(β-CD) supported, hydroxyapatite encapsulated γ-Fe2O3 (γ-Fe2O3@HAp@β-CD) was successfully prepared and evaluated as a solid-liquid phase transfer catalyst and also a molecular host system and nanoreactor for the nucleophilic ring-opening of epoxides in water for the preparation of β-azido alcohols, β-nitro alcohols, an...

Franz Effenberger * . Cyanohydrins have always held a place of importance both as technical products and as reagents in organic chemistry. It is surprising. therefore. that optically active cyanohydrins have been extensively investigated and employed for syntheses relatively recently. This can be explained by the fact that only in the past few years have enzymatic methods made chiral cyanohydri...

The present study, for the first time, presents a feasible protocol for the preparation of β-cyclodextrin/ imidazolium based dicationic ionic liquid, [βCD/Im](OTs)2, and its application as an efficient and eco-friendly microvessel and host ionic liquid system for the regioselective ring opening of the epoxides in water. No evidence for the formation of diol by-products or side reacti...

Hydroxynitrile lyases (HNLs) catalyze the cleavage of cyanohydrins to yield hydrocyanic acid (HCN) and the respective carbonyl compound and are key enzymes in the process of cyanogenesis in plants. In organic syntheses, HNLs are used as biocatalysts for the formation of enantiopure cyanohydrins. We determined the structure of the recently identified, R-selective HNL from Arabidopsis thaliana (A...

The present study, for the first time, presents a feasible protocol for the preparation of β-cyclodextrin/ imidazolium based dicationic ionic liquid, [βCD/Im](OTs)2, and its application as an efficient and eco-friendly microvessel and host ionic liquid system for the regioselective ring opening of the epoxides in water. No evidence for the formation of diol by-products or side reacti...

This thesis deals with the development of new methods for efficient synthesis and analysis in asymmetric catalysis. It focuses on the preparation of chiral cyanohydrins by enantioselective addition of cyanide to prochiral aldehydes. The initial part of the thesis describes the development of a dual Lewis acid– Lewis base activation system for efficient synthesis of chiral O-acylated and Ocarbon...

Using fumigation toxicity data of 11 natural and synthetic cyanohydrins to house fly (Musca domestica) and a stored-product pest, the lesser grain borer (Rhyzopertha dominica), the quantitative structure-activity relationships (QSAR) of cyanohydrins were examined by Oxford Molecular CAChe 3.2 and Microsoft Excel. This analysis used eight physicochemical parameters. Correlation between the LC(50...

Hydroxynitrile lyase (HNL) catalyzes the degradation of cyanohydrins and causes the release of hydrogen cyanide (cyanogenesis). HNL can enantioselectively produce cyanohydrins, which are valuable building blocks for the synthesis of fine chemicals and pharmaceuticals, and is used as an important biocatalyst in industrial biotechnology. Currently, HNLs are isolated from plants and bacteria. Beca...