Hops, extensively cultivated in China for their food and medicinal applications, currently lack well-defined chemical markers to evaluate variations in their quality. The study aimed to explore variations in the quality of Chinese hops by the chemical characteristics of hops, employing UPLC-Q-TOF/MS, integrated with chemical fingerprinting and chemometrics. The results indicated that Chinese hops are abundant in polyphenols and bitter acids. The integration of UPLC-Q-TOF/MS, Chemical fingerprinting, and chemometrics revealed to be an accurate and effective approach for assessing the quality of Chinese hops. In this study, ten important chemical markers were found to be useful in differentiating various hop varieties. Moreover, the support vector machine showed a prediction accuracy of 92.3077% in identifying Chinese hop varieties. The strategy of the study lays the groundwork for classifying Chinese hop varieties and serves as a prerequisite for future quality control studies, particularly focusing on chemical compositions.

Depression is a common mental disorder. In recent years, more and more attention has been paid to depression and its etiology and pathogenesis. This review aims to explore the neuroprotective and antidepressant effects of hop components. By establishing an in vitro cell damage model using PC12 cells induced by corticosterone (CORT) and an in vivo depression model through the intracranial injection of lipopolysaccharide (LPS) in mice, hop ethyl acetate extract (HEA) was used to study the protective effect and mechanism of HEA on neuronal cells in vitro and the antidepression effect and mechanism in vivo. The results showed that HEA increased the survival and decreased the rate of lactate dehydrogenase (LDH) release, apoptosis, and the ROS and NO content of CORT-induced PC12 cells. HEA alleviated depressive-like behavior, neuroinflammation, reduction of norepinephrine, and dendritic spines induced by intracerebroventricular injection of LPS in mice and increases the expression levels of BDNF, SNAP 25, and TrkB proteins without any significant side effects or toxicity. Hops demonstrated significant comprehensive utilization value, and this work provided an experimental basis for the role of hops in the treatment of depression and provided a basis for the development of HEA for antidepressant drugs or dietary therapy products.

Beer is among the most popular beverages in the world, with the production distributed uniformly between the biggest continents, so the utilization of brewing by-products is essential on a global scale. Among their potential recipients, the plastics industry offers extensive range of potential products. Herein, the presented study investigated the application of currently underutilized solid brewing by-products (brewers\' spent grain, spent hops, spent yeast) as fillers for highly-filled poly(ε-caprolactone)-based composites, providing the first direct connection between spent hops or spent yeast and the polymer composites. Comprehensive by-product characterization revealed differences in chemical composition. The elemental C:O ratio, protein content, and Trolox equivalent antioxidant capacity varied from 1.40 to 1.89, 12.9 to 32.4 wt%, and 2.41 to 10.24 mg/g, respectively, which was mirrored in the composites\' structure and performance. Morphological analysis pointed to the composition-driven hydrophilicity gap limiting interfacial adhesion for high shares of brewers\' spent grain and spent hops, due to high hydrophilicity induced by carbohydrate content. Phytochemicals and other components of applied by-products stimulated composites\' oxidative resistance, shifting oxidation onset temperature from 261 °C for matrix over 360 °C for high spent yeast shares. Simultaneously, spent yeast also provided compatibilizing effects for poly(ε-caprolactone)-based composites, reducing complex viscosity compared to other fillers and indicating its highest affinity to poly(ε-caprolactone)due to the lowest hydrophilicity gap. The presented results indicate that the proper selection of brewing by-products and adjustment of their shares creates an exciting possibility of engineering composites\' structure and performance, which can be transferred to other polymers differing with hydrophilicity.

The flavonoid xanthohumol is an important flavor substance in the brewing industry that has a wide variety of bioactivities. However, its unstable structure results in its low content in beer. Microbial biosynthesis is considered a sustainable and economically viable alternative. Here, we harness the yeast Saccharomyces cerevisiae for the de novo biosynthesis of xanthohumol from glucose by balancing the three parallel biosynthetic pathways, prenyltransferase engineering, enhancing precursor supply, constructing enzyme fusion, and peroxisomal engineering. These strategies improve the production of the key xanthohumol precursor demethylxanthohumol (DMX) by 83-fold and achieve the de novo biosynthesis of xanthohumol in yeast. We also reveal that prenylation is the key limiting step in DMX biosynthesis and develop tailored metabolic regulation strategies to enhance the DMAPP availability and prenylation efficiency. Our work provides feasible approaches for systematically engineering yeast cell factories for the de novo biosynthesis of complex natural products.

Xanthohumol (XN), possessing potent physiological activity, is exclusively derived from hops (Humulus lupulus L.) and exhibits high instability. However, its inherent instability often results in degradation during storage, leading to a decline in its activity due to the formation of various products. This study aimed to explore the stability of XN in beer under different storage conditions, establish or clarify degradation kinetic models, and understand the degradation mechanism. Our findings revealed that XN would degrade rapidly when exposed to high temperature and light. Its degradation followed a first-order kinetic model, involving reactions such as isomerization, hydration and ortho-position cyclization, resulting in the formation of five products. These insights shed light on the factors and mechanisms underlying the instability and degradability of XN, serving as a foundation for the development of a stable beer product enriched with functional XN.

Foam is one of the important characteristics of beer, including foamability, foam stability and foam texture. Protein Z (PZ) is considered to be an important component of beer foam. In this study, the interaction between PZ and humulinone, a widespread compound in aged hops, and the effect on foam properties of PZ were investigated. The fluorescence spectra showed that the stoichiometric ratio of humulinone to PZ was 4.25 ± 0.48: 1, and the binding constant was (1.64 ± 0.17) × 105 M-1. MD and FTIR results showed that the main force of interaction between PZ and humulinone was hydrogen bond, and the possible sites were Asn-37, Ser-292, Lys-290 and Pro-395. Moreover, the addition of humulinone greatly reduced the surface tension of PZ solution, and changed the secondary structure of PZ, which is beneficial for the foam stability. Under the influence of humulinone, the foamability, foam stability and foam texture of PZ all increased.

To study the chemical constituents from the stems and leaves of Humulus scandens, this study isolated thirteen compounds by different chromatographic methods including silica gel column, ODS, Sephadex LH-20 and preparative HPLC. Based on comprehensive analysis, the chemical structures were elucidated and identified as citrunohin A(1), chrysosplenetin(2), casticin(3), neoechinulin A(4), ethyl 1H-indole-3-carboxylate(5), 3-hydroxyacetyl-indole(6),(1H-indol-3-yl) oxoacetamide(7), inonotusic acid(8), arteannuin B(9), xanthotoxol(10), α-tocopherol quinone(11), eicosanyl-trans-p-coumarate(12), and 9-oxo-(10E,12E)-octadecadienoic acid(13). Among them, compound 1 was a new dihydrochalcone, and the other compounds were obtained from H. scandens for the first time.

On the background of antibiotic-free livestock husbandry, animal nutritionists are trying to find alternatives to antibiotics. Many herbs have been developed for animal diets to replace antibiotics. Humulus Scandens (HS) is also known as Humulus japonicus and Japanese hop in English, lü Cao () in Mandarin Chinese and kanamugura (カナムグラ) in Japanese. It is a traditional Chinese medicine with good environmental adaptability. It can grow rapidly and cover any area. Its high yield, strong vitality and medical value allow its potential to be used as an exogenous additive for animal diets to replace antibiotics. However, the knowledge about this herb is limited at present. This manuscript reviewed the processing method of HS and its application in livestock husbandry in order to provide references for its application.

As aging progresses, β-amyloid (Aβ) deposition and the resulting oxidative damage are key causes of aging diseases such as senior osteoporosis (SOP). Humulus lupulus L. (hops) is an important medicinal plant widely used in the food, beverage and pharmaceutical industries due to its strong antioxidant ability. In this study, APP/PS1 mutated transgenic mice and Aβ-injured osteoblasts were used to evaluate the protective effects of hops extracts (HLE) on SOP. Mice learning and memory levels were assessed by the Morris water maze. Mice femurs were prepared for bone micro-structures and immunohistochemistry experiments. The deposition of Aβ in the hippocampus, cortex and femurs were determined by Congo red staining. Moreover, protein expressions related to antioxidant pathways were evaluated by Western blotting. It was found that HLE markedly improved learning abilities and ameliorated memory impairment of APP/PS1 mice, as well as regulated antioxidant enzymes and bone metabolism proteins in mice serum. Micro-CT tests indicated that HLE enhanced BMD and improved micro-architectural parameters of mice femur. More importantly, it was discovered that HLE significantly reduced Aβ deposition both in the brain and femur. Further in vitro results showed HLE increased the bone mineralization nodule and reduced the ROS level of Aβ-injured osteoblasts. Additionally, HLE increased the expression of antioxidant related proteins Nrf2, HO-1, NQO1, FoxO1 and SOD-2. These results indicated that Humulus lupulus L. extract could protect against senior osteoporosis through inhibiting Aβ deposition and oxidative stress, which provides a reference for the clinical application of hops in the prevention and treatment of SOP.

BACKGROUND: The Humulus japonicus pollen is one of the most common allergenic pollens in China. However, little is unveiled regarding the allergenic components in Humulus japonicus pollen. Our study aimed to purify and identify the pathogenesis-related 1 (PR-1) protein from Humulus japonicus pollen, and to characterize the molecular and immunochemical properties of this novel allergen.
METHODS: The natural PR-1 protein (named as Hum j PR-1) was purified from Humulus japonicus pollen extracts with a combined strategy of chromatography, and identified by mass spectrometry. The coding sequence of Hum j PR-1 was confirmed by cDNA cloning. The recombinant Hum j PR-1 was expressed and purified from Escherichia coli. The allergenicity was assessed by immunoblot, enzyme-linked immunosorbent assay (ELISA), inhibition ELISA, and basophil activation test using Humulus japonicus allergic patients\' whole blood. The physicochemical properties and 3-dimensional structure of it were comprehensively characterized by in silico methods.
RESULTS: The allergenicity analysis revealed that 76.6 % (23/30) of the Humulus japonicus pollen allergic patients displayed specific IgE recognition of the natural Hum j PR-1. The cDNA sequence of Hum j PR-1 had a 516-bp open reading frame encoding 171 amino acids. Physicochemical analysis indicated that Hum j PR-1 was a stable and relatively thermostable protein. Hum j PR-1 shared a similar 3-dimensional folding pattern with other homologous allergens, which was a unique αβα sandwich structure containing 4 α-helices and 6 antiparallel β-sheets, encompassing 4 conserved CAP domain.
CONCLUSIONS: The natural PR-1 was firstly purified and characterized as a major allergenic allergen in Humulus japonicus pollen. These findings would contribute to developing diagnostic and therapeutic strategies for Humulus japonicus pollinosis.