Mandelic acid, an alpha hydroxy acid, has been used effectively as a urinary antiseptic, particularly as a bladder irrigant during urological procedures. It is a nontoxic substance that, after being ingested orally, is excreted in the urine. It is also used dermatologically to repair skin damage from prolonged sun exposure and as an acne treatment. Recently, a novel compound, a polymer derived from sulphuric acid treatment of mandelic acid, has been identified as a candidate topical contraceptive. Mandelic acid also with one aromatic ring can be explored as an additive that can be used to prepare mandelic acid-incorporated soy protein films[1].

Different contents of mandelic acid (2.5–10 %) were successfully incorporated in soy protein isolate (SPI). The effect of the 10 % mandelic acid content on the tensile and thermal properties of SPI is very interesting. One can see the increase in tensile strength as well as appearance of endotherms at 148.8 ℃ for S-10M unlike S-5M or S-2.5M. Higher elongation at break for SPI films at all the contents of mandelic acid suggests that mandelic acid may also be acting as a plasticizer in SPI films. Low water uptake of mandelic acid incorporated SPI films is attributed to the presence of aromatic groups, and same trend has been reported for salicylic acid and benzilic acid incorporated SPI films. The study shows that mandelic acid imparts better mechanical properties in SPI films at high content of mandelic acid. The presence of zone of inhibition for human (female) face bacterial growth suggests the antibacterial nature of mandelic acid incorporated SPI films.

Enantiomerically pure mandelic acid and its derivatives are important chiral analogs that are widely employed in the pharmaceutical synthetic industry, such as the manufacture of semisynthetic penicillins, cephalosporins or (S)-oxybutynin, and for the synthesis of various other chiral pharmaceuticals and drug intermediates[2]. They are also valuable chiral synthons that have been widely employed for the resolution of racemic compounds, like alcohols and amines.

References

[1] Rakesh Kumar, Antresh Kumar, Rajesh D. Anandjiwala. “Thermal and mechanical properties of mandelic acid-incorporated soy protein films.” Journal of Thermal Analysis and Calorimetry 123 2 (2015): 1273–1279.

[2] Jie Zhou. “Separation of mandelic acid and its derivatives with new immobilized cellulose chiral stationary phase.” Journal of Zhejiang University. Science. B 14 7 (2013): 615–20.