New alpha-Keto Acids in Green Plants. II. beta-Hydroxy- and gamma-Hydroxy-alpha-Ketobutyric Acids in Cowberries.

Alpha Hydroxy Acids in Cosmetic Dermatology

The cosmetic/drug dilemma: FDA regulation of alpha-hydroxy acids.

Alpha Hydroxy Acid (AHA) / Beta Hydroxy Acid (BHA)

AHAs act on both the epidermal and the dermal levels. When applied to the skin, AHAs stimulate the exfoliation of epidermal cells in the stratum corneum (s.c.) by interfering with the ionic bonding between these cells. This results in the sloughing off dull, rough skin and promotes cellular renewal. Initially used for treatment of hyperkeratosis and other skin conditions affecting s.c. turnover...

14-Membered cyclodepsipeptides with alternating beta-hydroxy and alpha-amino acids by cyclodimerization

The cyclodimerization (twinning) of beta-hydroxy acid amides of type 1 under ‘direct amide cyclization’ (DAC) conditions is described. Although other coupling methods also gave moderate results, best yields were obtained via DAC, reaching 88% for the cyclodimer 10. In all cases, when starting with racemic material, only the trans-substituted cyclodepsipeptides were isolated. Simple molecular mo...

Conformation specific and charge directed reactivity of radical cation intermediates of alpha-substituted (amino, hydroxy, and keto) bioactive carboxylic acids.

The reactivity of radical cation carboxylic acids is investigated on the basis of mass spectrometry, infrared-vacuum ultraviolet (IR-VUV) photoionization spectroscopy, and high level correlated ab initio calculations. Their reactivity is found to be highly conformation specific and is governed by their initial charge distribution following ionization. In the present work, the radical cations of...