How Hops Could Help Fight Disease

We’re all familiar with hops as the ingredient that imparts the distinctive bitterness to some types of beer. Over time, the degradation of the acids contained within hops alters the flavour of the beer. In fact, analysing the hop alpha-acids using chromatography can allow brewers to see how a particular beer has aged.

What you might not know about are hops’ powerful health benefits. Some of the components contained within the cone-shaped buds have been proven to fight disease and inhibit the growth and spread of bacteria.

The components that impart these benefits are known as humulones and lupulones. Humulones are alpha-acids that have been proven to have anti-inflammatory and anti-cancer properties; whilst lupulones are beta-acids whose precise medical benefits are not yet fully understood.

The problem of extraction

In order to access the two acids and their beneficial properties, scientists must separate out the hops into its various components — and this is what scientists at the University of Idaho have set out to do. They have used high performance liquid chromatography (HPLC) to isolate and extract individual chemicals from hops.

However, they must be certain that the substances they have extracted are indeed humulones and lupulones. This is normally achieved by comparing the extracted compounds to analytical standards — and this is where the process hits a stumbling block.

As yet, no analytical standards exist for humulones or lupulones — so scientists cannot be certain what they have extracted. The team from Idaho have set out to create standards — from scratch. For any instrumental technique, the use of standards is one of the key requirements in obtaining reproducible and repeatable results — as discussed in the article, Automated Analysis of Open-Access HPLC Instrumentation Metrics.

Synthesizing humulones — hops to it

As the lead researcher on the project — Kristopher Waynant — states in a press release:

‘When researchers extract healthful chemicals from hops, they first have to determine whether they have separated out the specific compounds they're interested in. But if you can figure out how to make these compounds from scratch, you know they are the right ones.’

The process of creating such standards involves a great deal of trial and error. Waynant, and his assistant Lucas Sass, have already fine-tuned the majority of the technique, but still need to tweak the last few steps.

They begin with phloroglucinol, a compound found in plants and widely available on the market. Using acylation, prenylation and transition-metal catalysis — the team have arrived at an asymmetric prototype for three different strains of humulones. Finally, they must work out how to effectively convert the unfinished substance into the desired humulone variety.

If Waynant and Sass are successful in synthesising the chemicals in a lab environment, they will have made great strides in harnessing some of the health benefits found in hops. The next step is to work with pharmaceutical companies to develop a range of preventions and treatments.

So, off to the pub for a healthy beverage.