Aroma Profile Development in Beer Fermented with Azacca, Idaho-7, and Sultana Hops.

Hops are among the most costly and environmentally impactful raw materials used in brewing, yet they play a crucial role in the aroma of beer. However, predicting beer aroma based on hop variety or hopping method remains arduous. This is partly because hop oils are unique for each hop variety, and they may be biotransformed by yeast enzymes during fermentation. Even slight molecular structure modifications can dramatically affect the organoleptic properties of beer. Through combined chemical and sensory analysis of dry-hopped beers prepared with different hop varieties (Azacca, Idaho-7, and Sultana), this work aimed to profile the aromas and the overall biotransformation processes taking place during fermentation. A total of 51 volatile organic compounds (VOCs) were semi-quantified and monitored: 19 esters, 13 sesquiterpenes, 7 ketones, 7 alcohols, 4 monoterpenes, and 1 volatile acid. There were significant similarities in the measured analytes and perceived aromas of these beers, but one hop variety (Sultana) delivered an increased quantity of unique aromas and an increased concentration of volatiles in the headspace for the same quantity of hop pellets added. This work provides practical information to brewers who utilize hops in beer production.

Improved synthesis of deoxyalpinoid B and quantification of antileishmanial activity of deoxyalpinoid B and sulforaphane.

The total synthesis and antileishmanial activity of deoxyalpinoid B is reported via a cationic gold-catalyzed Meyer-Schuster rearrangement. The activity of deoxyalpinoid B and a known inducer of oxidative stress, sulforaphane, against Leishmania donovani and Leishmania infantatum are both reported for the first time. Both compounds exhibit potent antileishmanial activity against both species. We hypothesize that the activation of intracellular oxidative stress is a key molecular response for the inhibition of Leishmania.

Efficient total synthesis of three alpinoids via the Au(I)-catalyzed Meyer-Schuster rearrangement.

The total syntheses of three structurally related natural products, deoxyalpinoid B, deoxyalpinoid A, and alpinoid F, are reported, and each features a Au(I)-catalyzed Meyer-Schuster rearrangement as the key step. The synthesis of alpinoid F is reported for the first time. The syntheses of these natural products, all of which exhibit potent anticancer activity, are readily amenable to the preparation of structural analogs.