Occurrence of Theaspirane and its Odorant Degradation Products in Hop and Beer

Abstract

In model oxidized media, six theaspirane-derived compounds were identified by gas chromatography-high resolution mass spectrometry: 4-hydroxy-7,8-dihydro-β-ionone, 6-hydroxy-7,8-dihydro-α-ionone, dihydrodehydro-β-ionone, two monoepoxides, and a derived alcohol. Only 4-hydroxy-7,8-dihydro-β-ionone and dihydrodehydro-β-ionone have been described previously in the literature. Investigation of hop revealed five of these compounds in free form together with theaspirane (especially in the Mosaic variety), while the Citra and Amarillo hop varieties emerged as very interesting for the release of theaspirane, 4-hydroxy-7,8-dihydro-β-ionone, and dihydrodehydro-β-ionone from glucoside precursors. For the first time, theaspirane, 4-hydroxy-7,8-dihydro-β-ionone, 6-hydroxy-7,8-dihydro-α-ionone, and both monoepoxides were found in a fresh commercial top fermentation beer (only theaspirane, 4-hydroxy-7,8-dihydro-β-ionone, and dihydrodehydro-β-ionone have recently been mentioned as Gueuze constituents).

Anticancer and Antioxidant Activities of the Root Extract of the Carnivorous Pitcher Plant Sarracenia purpurea

“…Moreover, 7,8-dihydro-α-ionone is also abundant in some plants, such as Persicaria hydropiper [47] and Ecballium elaterium [48]. Furthermore, 7,8-dihydro-α-ionone is a phenolic compound and known to contribute to the plant's antioxidant effects [48,49]. Other abundant compounds (>2.4%) in S. purpurea-root-acetone (Table 5), i.e., 24-norursa-3,12-diene [50], α-amyrin [51], stigmast-5-en-3-ol [52], botulin [53], and 24-noroleana-3,12-diene also possess antioxidant activities.…”

“…By analyzing GC-MS, 7,8-dihydro-α-ionone (Table 5) was the major compound present in S. purpurea-root-acetone. Moreover, 7,8-dihydro-αionone is a strong antioxidant [48,49]. Recent studies have demonstrated anti-proliferative-, anti-metastatic-, and apoptosis-induction properties of β-ionone, in vitro and in vivo [72].…”