Poly(tertiary phosphines and arsines). 17. Poly(tertiary phosphines) containing terminal neomenthyl groups as ligands in asymmetric homogeneous hydrogenation catalysts

A Review on Saliva-Based Health Diagnostics: Biomarker Selection and Future Directions

The human body has a unique way of saying when something is wrong with it. The molecules in the body fluids can be helpful in the early detection of diseases by enabling health and preventing disease progression. These biomarkers enabling better healthcare are becoming an extensive area of research interest. Biosensors that detect these biomarkers are becoming the future, especially Point Of Care (POC) biosensors that remove the need to be physically present in the hospital. Detection of complex and systemic diseases using biosensors has a long way to go. Saliva-based biosensors are gaining attention among body fluids due to their non-invasive collection and ability to detect periodontal disease and identify systemic diseases. The possibility of saliva-based diagnostic biosensors has gained much publicity, with companies sending home kits for ancestry prediction. Saliva-based testing for covid 19 has revealed effective clinical use and relevance of the economic collection. Based on universal biomarkers, the detection of systemic diseases is a booming research arena. Lots of research on saliva-based biosensors is available, but it still poses challenges and limitations as POC devices. This review paper talks about the relevance of saliva and its usefulness as a biosensor. Also, it has recommendations that need to be considered to enable it as a possible diagnostic tool.

Graphical Abstract

First Resolution of a Free Secondary Phosphine Chiral at Phosphorus and Stereospecific Formation and Structural Characterization of a Homochiral Secondary Phosphine-Borane Complex

The R(P) diastereomer of (-)-menthylmesitylphosphine, (R(P))-1, has been isolated with high configurational purity at phosphorus by fractional crystallization of an (R(P))-1/(S(P))-1 = 43/57 mixture from acetonitrile containing a trace of sodium acetylacetonate as a proton scavenger or by deboranation of the corresponding borane complex (S(P))-2 with diethylamine, thereby effecting the first resolution of a secondary phosphine chiral at phosphorus. The crystal and molecular structure of (S(P))-2 has been determined. The ready isolation of (S(P))-2 of 97% diastereomeric purity in 66% yield from an equilibrium (R(P))-2/(S(P))-2 = 28/72 mixture in n-hexane by second-order asymmetric transformation and its quantitative and stereospecific conversion under mild conditions into (R(P))-1 of similar purity augurs well for the future of the resolved secondary phosphines in stereoselective syntheses.