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Liquorice is a popular medicinal herb containing antioxidative and anti-inflammatory bioactive components.
The effects of liquorice against Parkinson’s disease cell death were investigated with focus on Isoliquiritigenin (ISL) a key component of liquorice.
These results provide the first evidence that Isoliquiritigenin can protect dopaminergic cells under oxidative stress conditions by regulating the apoptotic process.
Dopaminergic cells are collections of neurons in the central nervous system that contain the neurotransmitter dopamine.
Hwang et al,
Bioscience, biotechnology, and biochemistry (Mar 27, 2012)
Asymmetric hydrogentation of unfunctionalised olefins/enamines/imines
The reaction survey found that the predominant strategy for the introduction of chirality was through classical chemical resolutions as opposed to introductions through biotransformation or transition metal or organometallic catalytic means.
Asymmetric hydrogenation provides an elegant methodology for the introduction of chirality, meeting many of the goals of green chemistry and is finding increasing application in API synthesis.47
The efficiency of this approach is elegantly exemplified by the Merck second generation synthesis of sitagliptin 5 (Scheme ), where an unprecedented final stage asymmetric hydrogenation of the unprotected enamide 6 resulted in an increase in overall yield of almost 50% and produced 100 kg less waste per kg sitagliptin48 when compared with the first generation approach.49
|Scheme The synthesis of sitagliptin.|
There are challenging areas remaining within the field, for example, the hydrogenation of enamides and related substrates in the synthesis of amino…
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Essentially all medicines and current drug candidates contain at least one basic nitrogen atom. A common approach to the synthesis of amines is to reduce the corresponding amide with a hydride reagent such as LiAlH4, DIBAL, RedAl, B2H6, Et3SiH, or polymethylhydroxysilane (PMHS).
The reaction survey reported that reduction of amides to amines was used in only 0.6% of chemical transformations; this number would surely be higher if safer methods for use on scale were available. The survey indicated that the number of amide reductions was equally split between diborane and hydride reagents.
Lithium aluminium hydride,
having a molecular weight of 38 and four hydrides per molecule, has the highest hydride density and is frequently used, even though it co-generates an inorganic by-product (lithium aluminum hydroxide) which is difficult to separate from the product. The workup procedure recommended by one bulk supplier…
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An analog of Sildenafil which has been used as an illegal adulterant in some dietary supplements.
856190-47-1 cas no
- 7H-Pyrazolo(4,3-d)pyrimidine-7-thione, 5-(5-(((3R,5S)-3,5-dimethyl-1-piperazinyl)sulfonyl)-2-ethoxyphenyl)-1,6-dihydro-1-methyl-3-propyl-, rel-
- Sildenafil thione
Sulfoaildenafil (thioaildenafil) is a synthetic chemical compound that is a structural analog of sildenafil (Viagra). It was first reported in 2005, and it is not approved by any health regulation agency. Like sildenafil, sulfoaildenafil is a phosphodiesterase type 5 inhibitor.
Sulfoaildenafil has been found as an adulterant in a variety of supplements which are sold as “natural” or “herbal” sexual enhancement products. A range of designer analogues of USA FDA-approved inhibitors of type-5 cGMP-specific phosphodiesterase (PDE5), such as sildenafil and vardenafil, have been detected in recent years as adulturants in over-the-counter herbal aphrodisiac products and dietary supplements, in…
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