An updated review of the genus Rhododendron since 2010: Traditional uses, phytochemistry, and pharmacology.

Rhododendron, the largest genus of Ericaceae, consists of approximately 1000 species that are widely distributed in Europe, Asia, and North America but mainly exist in Asia. Rhododendron plants have not only good ornamental and economic value but also significant medicinal potential. In China, many Rhododendron plants are used as traditional Chinese medicine or ethnic medicine for the treatment of respiratory diseases, pain, bleeding and inflammation. Rhododendron is known for its abundant metabolites, especially diterpenoids. In the past 13 years, a total of 610 chemical constituents were reported from Rhododendron plants, including 222 diterpenoids, 122 triterpenoids, 103 meroterpenoids, 71 flavonoids and 92 other constituents (lignans, phenylpropanoids, phenolic acids, monoterpenoids, sesquiterpenoids, coumarins, steroids, fatty acids). Moreover, the bioactivities of various extracts and isolates, both in vitro and in vivo, were also investigated. Our review summarized the research progress of Rhododendron regarding traditional uses, phytochemistry and pharmacology in the past 13 years (2010 to December 2022), which will provide new insight for prompting further research on Rhododendron application and drug development.

Comparative studies of fermented coffee fruits post-treatments on chemical and sensory properties of roasted beans in Yunnan, China.

In this study, medium roasted coffee with four different fermented coffee fruits post-treatments (dry, wet, semi-dry and hot air dry) was used as the material. Chemical profile and sensorial analysis were used to comprehensively analyze the effects of post-treatments on coffee flavor characteristics from multiple dimensions. A total of 31 water-soluble chemical components and 39 volatile compounds were identified in roasted coffee, and distinct post-treatments based on chemical orientation make coffee highly differentiated. In addition, the principal component analysis (PCA) of the chemical composition integrated data set showed that the first two principal components could explain 54.9% of the sample variability. All four post-treatments can be classified as "specialty coffees" according to the Specialty Coffee Association (SCA) protocol, with various organoleptic characteristics and flavor attributes. As a result, the fermented coffee fruits post-treatment method further determines the quality characteristics of coffee, thus meeting the needs of different niche markets.

Identification and screening of novel diterpenoids from roasted arabica coffee in the regulation of lipid content in white adipocytes.

Previous studies have shown that coffee has a role in regulating lipid metabolism. However, the active compounds and pharmacological mechanism(s) are still unclear. Here, four new coffee diterpenoids (1-4) were identified from roasted arabica coffee (Coffea arabica L.) beans, and together with 31 known coffee diterpenoids (5-35), their bioactivities in the regulation of lipid content in white adipocytes were evaluated. Based on their structures and correlated bioactivities, we proposed that the α,ß-unsaturated-γ-lactone moiety and hydroxyl group at C-3 are required for the bioactivity. Furthermore, the pharmacological approaches revealed that the active new diterpenoid, dehydrocaffarolide B, inhibited the Akt/mTOR/GSK3ß pathway and arrested cells in the G0/G1 phase of the mitotic clonal expansion process during the adipocyte differentiation and maturation, eventually resulting in the blunting of lipid accumulation in the adipocytes. Collectively, our findings identified four new diterpenoids of arabica coffee and elucidated a mechanism of an active lactone-type diterpenoid in the regulation of lipid content in white adipocytes.

Anaerobic germination of green coffee beans: A novel strategy to improve the quality of commercial Arabica coffee.

This study aimed to improve the brewing quality of commercial Arabica coffee through anaerobic germination. Changes in important compounds and cupping scores of germination roasting coffee with different germination degrees were investigated by 1H NMR, HS-SPME-GC-MS and sensory analysis. Statistical analysis of multivariate analysis results indicated that 6 water-soluble chemical components and 8 volatile chemical components have the potential to be markers of germinated roasting coffee. In addition, germination significantly reduced caffeine content and acrylamide formation in roasted coffee. Sensory analysis according to the Specialty Coffee Association (SCA) cupping protocol demonstrated that anaerobic germination modified flavor attributes, improved the quality, and increased sensory scores. Furthermore, anaerobic sprouting increased fruity descriptors, but over-sprouting did not improve overall attributes while producing both fermentative and vegetable descriptors. Therefore, suitable anaerobic germination of green coffee beans can be used as a new strategy to improve the flavor of commercial Arabica coffee.

Diverse meroterpenoids with α-glucosidase inhibitory activity from Ganoderma cochlear.

Three new meroterpenoids, cochlearins J-L (1-3) and three known meroterpenoids (4-6) were isolated from the fruiting bodies of Ganoderma cochlear. NMR (1H and 13C NMR, 1H - 1H COSY, HSQC, HMBC and ROESY), and HRESIMS were employed for the structure elucidation of new compounds. The stereostructures of 1-3 were confirmed by calculated ECD and optical rotation methods. Furthermore, compounds (+)-1, (-)-1, (+)-2, (-)-2, (+)-3, (-)-3, and 4-6 were evaluated for their α-glucosidase inhibitory activity. The results showed that compounds (+)-1, (-)-1 and (+)-2 exhibited stronger inhibition against α-glucosidase with IC50 values of 24.18 ± 1.98, 26.49 ± 3.20 and 29.68 ± 2.73 µM, respectively, compared to the positive control ursolic acid (49.65 ± 2.21 µM). The molecular docking experiments reveal that (+)-2 and (-)-2 had different binding mode with α-glucosidase, leading to their different inhibition.

Unusual ent-Kaurane Diterpenes from the Coffea Cultivar S288 Coffee Beans and Molecular Docking to α-Glucosidase.

A total of 11 new (1-11) and 2 known (12 and 13) ent-kaurane diterpene derivatives were identified from the roasted beans of Coffea cultivar S288. Their structures were established by extensive spectroscopic analysis, including one- and two-dimensional nuclear magnetic resonance (heteronuclear single-quantum correlation, heteronuclear multiple-bond correlation, correlation spectroscopy, and rotating-frame Overhauser enhancement spectroscopy), high-resolution electrospray ionization mass spectrometry, and X-ray analyses. Cafespirone acid A (1) represents the first example of diterpene featuring a spirocyclic skeleton constructed from a 6/6/5 tricyclic system. Cafeane acid A (2) possesses a 6/6/6/5 tetracyclic system as a result of the C/D ring rearrangement. Furthermore, compounds 1-12 were evaluated for their α-glucosidase inhibitory activity. The results showed that compounds 2, 4, 5, 6, 7, 10, and 11 had a moderate inhibitory effect on α-glucosidase, and half-maximal inhibitory concentration values of compounds 4, 6, 7, and 10 were 18.76 ± 1.46, 4.88 ± 0.03, 12.35 ± 0.91, and 12.64 ± 0.59 µM, respectively, compared to the positive control acarbose (60.71 ± 16.45 µM). Additionally, the molecular docking experiments showed that the carbonyl group at C-19 of compounds 4, 6, and 7 formed strong hydrogen bonds with ARG315, which may make them have moderate inhibitory activity.

Review on factors affecting coffee volatiles: from seed to cup.

The objective of this review is to evaluate the influence of six factors on coffee volatiles. At present, the poor aroma from robusta or low-quality arabica coffee can be significantly improved by advanced technology, and this subject will continue to be further studied. On the other hand, inoculating various starter cultures in green coffee beans has become a popular research direction for promoting coffee aroma and flavor. Several surveys have indicated that shade and altitude can affect the content of coffee aroma precursors and volatile organic compounds (VOCs), which remain to be fully elucidated. The emergence of the new roasting process has greatly enriched the aroma composition of coffee. Cold-brew coffee is one of the most popular trends in coffee extraction currently, and its influence on coffee aroma is worthy of in-depth and detailed study. Omics technology will be one of the most important means to analyze coffee aroma components and their quality formation mechanism. A better understanding of the effect of each parameter on VOCs would assist coffee researchers and producers in the optimal selection of post-harvest parameters that favor the continuous production of flavorful and top-class coffee beans and beverages. © 2021 Society of Chemical Industry.

Morphological Changes and Component Characterization of Coffee Silverskin.

Nuclear magnetic resonance (NMR) spectroscopy was used for the qualitative and quantitative analysis of aqueous extracts of unroasted and roasted coffee silverskin (CS). Twenty compounds were identified from 1D and 2D NMR spectra, including caffeine, chlorogenic acid (CGA), trigonelline, fructose, glucose, sucrose, etc. For the first time, the presence of trigonelline was detected in CS. Results of the quantitative analysis showed that the total amount of the main components after roasting was reduced by 45.6% compared with values before roasting. Sugars in the water extracts were the main components in CS, and fructose was the most abundant sugar, its relative content accounting for 38.7% and 38.4% in unroasted and roasted CS, respectively. Moreover, 1D NMR combined with 2D NMR technology shows application prospects in the rapid, non-destructive detection of CS. In addition, it was observed by optical microscopy and scanning electron microscopy (SEM) that the morphology of CS changed obviously before and after roasting.

Macathiohydantoin L, a Novel Thiohydantoin Bearing a Thioxohexahydroimidazo [1,5-a] Pyridine Moiety from Maca (Lepidium meyenii Walp.).

Five new thiohydantoin derivatives (1-5) were isolated from the rhizomes of Lepidium meyenii Walp. NMR (1H and 13C NMR, 1H-1H COSY, HSQC, and HMBC), HRESIMS, and ECD were employed for the structure elucidation of new compounds. Significantly, the structure of compound 1 was the first example of thiohydantoins with thioxohexahydroimidazo [1,5-a] pyridine moiety. Additionally, compounds 2 and 3 possess rare disulfide bonds. Except for compound 4, all isolates were assessed for neuroprotective activities in corticosterone (CORT)-stimulated PC12 cell damage. Among them, compound (-)-3 exhibited moderate neuroprotective activity (cell viability: 68.63%, 20 µM) compared to the positive control desipramine (DIM) (cell viability: 88.49%, 10 µM).

Lepipyrrolins A-B, two new dimeric pyrrole 2-carbaldehyde alkaloids from the tubers of Lepidium meyenii.

Nine new pyrrole alkaloids, including two undescribed dimeric pyrrole 2­carbaldehyde alkaloids, lepipyrrolins A-B (1-2), seven pyrrole-alkaloid derivatives, macapyrrolins D-J (3-9), along with three known ones (10-12) were isolated from the rhizomes of Lepidium meyenii. Their structures and absolute configurations were demonstrated by extensive spectroscopic data (1D, 2D NMR, HRESIMS), and calculated electronic circular dichroism (ECD) experiment. Compounds 1, 3-12 were tested for their nitric oxide inhibitory effects. Furthermore, compound 1 was evaluated for its cytotoxic activity against five human tumor cell lines (HL-60, SMMC-7221, A549, MCF-7, and SW480) in vitro, and displayed selective cytotoxicity against SMMC-7721 with IC50 value of 16.78 ± 0.49 µM.

Label-free cell phenotypic study of opioid receptors and discovery of novel mu opioid ligands from natural products.

ETHNOPHARMACOLOGICAL RELEVANCE: Mu opioid receptor (MOR) is mainly a drug target for analgesia. Opioid-like agonists such as morphine have been clinically used for analgesia but have potential adverse effects. MOR antagonists have been demonstrated to alleviate these side effects. Plants (Carthamus tinctorius L, Cynanchum otophyllum C. K. Schneid., Coffea arabica L., Prinsepia utilis Royle and Lepidium meyenii Walp.) and Ganoderma fungi (Ganoderma hainanense J. D. Zhao, Ganoderma capense (Lloyd) Teng, Ganoderma cochlear (Blume et Nees) Bres., Ganoderma resinaceum Boud and Ganoderma applanatum (Pers.) Pat.) are traditional medicines with beneficial effects on immunoregulation, analgesia and the nervous system, but whether MORs are engaged in their effects remains unknown. AIM OF THE STUDY: This work aimed to identify MOR ligands among compounds isolated from the above-mentioned 10 species, and to investigate selectivity against four opioid receptor subtypes. By analyzing the structure-activity relationship and off-target effects, we could provide a new direction for the future development of MOR drugs. MATERIALS AND METHODS: Four opioid receptor subtype models, including MOR, delta (DOR), kappa (KOR) and nop (NOR), were established with a label-free phenotypic dynamic mass redistribution assay to systematically profile the pharmacological properties of known ligands. Then, 82 natural compounds derived from the 10 species were screened against MOR to identify new ligands. The selectivity of the new ligands was characterized against the four subtypes, and off-target effects were also investigated on eight G protein-coupled receptors (GPCRs). RESULTS: The pharmacological properties of known ligands on transfected HEK293T-MOR, HEK293-DOR, HEK293-KOR and HEK293-NOR cell lines were characterized. Seven compounds purified from Ganoderma cochlear (Blume et Nees) Bres. and Carthamus tinctorius L were MOR antagonists with micromolar potency. Among them, compound 35 showed the strongest antagonistic activity on MOR with an IC50 value of 10.0 ± 3.0 µM. To a certain extent, these seven new antagonists, exhibited antagonistic activity on the other opioid receptor subtypes, and they had almost no effect on other GPCRs, including CB1, CB2, M2 and beta2AR. Additionally, a compound from Lepidium meyenii Walp. displayed MOR agonistic activity. CONCLUSIONS: The established screening models opened new avenues for the discovery and evaluation of opioid receptor ligand selectivity. Together, the novel MOR antagonists and agonists will enrich the inventory of MOR ligands and benefit related therapies.

Effect of roasting degree of coffee beans on sensory evaluation: Research from the perspective of major chemical ingredients.

As the most consumed beverage in the world, the material basis of the sensory quality for roasted coffee beans has always received much attention. The objective of the present study was to clarify the physical morphology changes, main chemical ingredients and cupping scores of arabica coffee beans of different roasting degrees, by scanning electron microscopy (SEM), nuclear magnetic resonance (NMR) and sensory analysis, respectively. Statistical analysis of the data by multivariate analysis demonstrated that trigonelline, sugars, malate, quinic acids, γ-butyro-lactone and acetate have the potential to be new roasting markers. Additionally, in all the sensory indicators, body and acidity were found to be susceptible to roasting degree. Basing on cluster heatmap and sensory molecular network, the complex relationships between sensory indicators and ingredients were discussed. The results of partial least squares regression (PLSR) showed that the content of the main coffee ingredients can be used to predict the body score.

Effects of 23-epi-26-deoxyactein on adipogenesis in 3T3-L1 preadipocytes and diet-induced obesity in C57BL/6 mice.

BACKGROUND: The ethanolic extract of Actaea racemosa L. (Cimicifuga racemosa (L.) Nutt.) has recently been reported to ameliorate obesity-related insulin resistance, hyperlipidemia, and fatty liver in rodents. However, it remains unclear which A. racemosa components are responsible for these beneficial effects. PURPOSE: We aimed to examine the anti-obesity potential of 23-epi-26-deoxyactein (DA), which is contained in the ethanolic extracts of A. racemosa. STUDY DESIGN AND METHODS: To evaluate the effects of DA on adipogenesis in 3T3-L1 preadipocytes and diet-induced obesity in C57BL/6 mice, in vitro and in vivo tests were performed. For in vitro assessment, we used Oil red O staining that showed lipid accumulation in differentiated 3T3-L1 cells. For in vivo tests, male 5-week-old C57BL/6 mice were fed with low-fat diet (LFD), high-fat diet (HFD), HFD with 10 mg/kg/d luteolin (LU; positive control drug), HFD with 1 mg/kg/d DA, and HFD with 5 mg/kg/d DA for 12 weeks, respectively. Glucose and insulin tolerance tests were performed at week 17. The lipid deposition of adipose tissue and liver was visualized by hematoxylin and eosin staining. Real-time PCR showed mRNA levels of genes involved in adipogenesis, lipogenesis, and lipolysis. AMPK signaling and SIRT1-FOXO1 pathway were assessed by real-time PCR and western blot. RESULTS: 10 µM DA and 20 µM LU treatments inhibited 3T3-L1 adipogenesis through down-regulating the expression of C/ebpα, C/ebpß, and Pparγ, which are the critical adipogenic transcription factors. The in vivo results showed that 5 mg/kg/d DA and 10 mg/kg/d LU significantly lowered body weight gain, fat mass, and liver weight in HFD-fed mice. Meanwhile, DA and LU also reduced insulin resistance and serum lipoprotein levels in HFD-fed mice. Mechanistic studies showed that DA and LU promoted adipocyte lipolysis in mice through activating the AMPK signaling and SIRT1-FOXO1 pathway. CONCLUSION: The in vitro results indicate that 10 µM DA suppresses adipogenesis in 3T3-L1 preadipocytes. The in vivo treatment with 5 mg/kg/d DA ameliorates diet-induced obesity in mice, suggesting that DA is a promising natural compound for the treatment of obesity and related metabolic diseases.

Cycloartane triterpene glycosides from rhizomes of Cimicifuga foetida L. with lipid-lowering activity on 3T3-L1 adipocytes.

Six previously undescribed cycloartane triterpenes glycosides, cimimanols A-F (1-6), together with thirteen known analogues (7-19) were isolated from the rhizomes of Cimicifuga foetida. Among them, cimimanol A (1) was the first example of cycloartane triterpene glycoside featuring a unique cyclic carbonate, and cimimanol B (2) was a rare trinortriterpene glycoside. The chemical structures and absolute configurations of new compounds were determined on the basis of comprehensive spectroscopic analysis, chemical method, and X-ray crystal diffraction, as well as quantum chemistry calculations. Finally, all these compounds were evaluated for their lipid-lowering effect on 3T3-L1 adipocytes. Compounds 1-3, 6-10, 12-16, 18-19 could significantly reduce the fat accumulation in 3T3-L1 adipocytes, especially compounds 8, 9, 14, and 15 exhibited strong lipid-lowering effect at the concentration of 10 µM, with inhibition rates ranging from 8.35% to 12.07%.

Excavation of coffee maturity markers and further research on their changes in coffee cherries of different maturity.

1H NMR detection combined with partial least squares discriminant analysis (PLS-DA) was used to establish models for distinguishing between Arabica coffee immature beans and mature beans. By screening Variable importance in projection (VIP) values of the discriminant model, sugars, caffeoylquinic acids (CQAs), caffeine, trigonelline and quinic acid were confirmed as maturity markers. Response surface method (RSM) was used to filter optimal condition for the simultaneous extraction of sugars, 5-caffeoylquinic acids (5-CQA), caffeine and trigonelline and the best condition obtained was: extraction time 120 min, extraction temperature 50 °C, methanol/water 0.20, solvent/solute 274.65. Under this condition, the content of maturity markers in eight different maturity coffee green beans and pulp were analyzed, and their possible biological functions as well as impact on cupping score were further discussed.

Lactam ent-Kaurane Diterpene: A New Class of Diterpenoids Present in Roasted Beans of Coffea arabica.

Seven new lactam ent-kaurane diterpenoids, cafemides A-G (1-7), were isolated from roasted beans of Coffea arabica. Their structures were elucidated by extensive spectroscopic analysis including 1D, 2D NMR (heteronuclear single quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC), 1H-1H correlation spectroscopy (COSY), and rotating frame Overhauser effect spectroscopy (ROESY)), high-resolution electrospray ionization mass spectrometry (HRESIMS), and IR spectra. They were divided into subtype I-III according to the structure. Further, with the aid of liquid chromatography-tandem mass spectrometry (LC-MS/MS) based molecular network, seven (8-14) subtype II diterpenoids were successfully identified. In addition, a variety of other subtypes of N-containing diterpenoids have been proven in roasted coffee. Compounds 1, 2, 3, 5, and 7 showed a moderate inhibitory effect on α-glucosidase with an IC50 value of 8.28 ± 0.62 µM, 38.23 ± 8.87 µM, 28.94 ± 1.42 µM, 12.44 ± 1.37 µM, and 22.2 ± 5.34 µM, respectively. To the best of our knowledge, this is the first time that N-containing diterpenoids have been reported in coffee.

A Ganoderma-Derived Compound Exerts Inhibitory Effect Through Formyl Peptide Receptor 2.

Formyl peptide receptors (FPRs) are G protein-coupled receptors (GPCRs) widely expressed in neutrophils and other phagocytes. FPRs play important roles in host defense, inflammation, and the pathogenesis of infectious and inflammatory diseases. Because of these functions, FPRs are potential targets for anti-inflammatory therapies. In order to search for potentially novel anti-inflammatory agents, we examined Ganoderma (Lingzhi), a Chinese medicinal herbs known for its anti-inflammatory effects, and found that compound 18 (C18) derived from Ganoderma cochlear could limit the inflammatory response through FPR-related signaling pathways. Further studies showed that C18 could bind to FPR2 and induce conformation change of the receptor that differed from the conformational change induced by the pan-agonist, WKYMVm. C18 inhibited at the receptor level and blocked WKYMVm signaling through FPR2, resulting in reduced superoxide production and compromised cell chemotaxis. These results identified for the first time that a Ganoderma-derived component with inhibitory effects that acts through a G protein-coupled receptor FPR2. Considering its less than optimal IC50 value, further optimization of C18 would be necessary for future applications.

Structurally diverse lanostane triterpenoids from medicinal and edible mushroom Ganoderma resinaceum Boud.

Ganoderma resinaceum is a multi-purpose herbal medicine that is homologous to functional food that has long been used for enhancing health and treating chronic hepatopathy in Traditional Chinese Medicine. In a search program to discover the key bioactive composition of G. resinaceum, sixteen new lanostane-type triterpenoids (1-16), and twenty known analogues (17-36) were isolated from the fruiting bodies of G. resinaceum. Spectroscopic analyses and X-ray crystallography were used to determine the new structures. Furthermore, the spectroscopic properties of 15ß-hydroxy-4,4,14α- trimethyl-3,7,11,20-tetraoxo-5α-pregn-8-ene (15) and 15α-hydroxy-4,4,14α-trimethyl- 3,7,11,20-tetraoxo-5α-pregn-8-ene (34) indicated a potential structural misassignment of their analogues, lucidone E and lucidone H, reported previously. To probe this hypothesis, ROESY experiments and single-crystal X-ray diffraction analysis were conducted. These results undoubtedly reassigned the structure of lucidone E and lucidone H. Biological evaluation of the selected compounds disclosed that compounds 3, 4, 7/21, 11, 12, 13/14, 17, 18, 24/25, 27, 30, 31, and 35 had significant hepatoprotective activities, due to their remarkable in vitro inhibitory activities against the increase of ALT and AST levels in HepG2 cells induced by H2O2.

Buxus alkaloid compound destabilizes mutant p53 through inhibition of the HSF1 chaperone axis.

BACKGROUND: P53 is the most frequently mutated gene in most tumour types, and the mutant p53 protein accumulates at high levels in tumours to promote tumour development and progression. Thus, targeting mutant p53 for degradation is one of the therapeutic strategies used to manage tumours that depend on mutant p53 for survival. Buxus alkaloids are traditionally used in the treatment of cardiovascular diseases. We found that triterpenoid alkaloids extracted from Buxus sinica found in the Yunnan Province exhibit anticancer activity by depleting mutant p53 levels in colon cancer cells. PURPOSE: To explore the anticancer mechanism of action of the triterpenoid alkaloid KBA01 compound by targeting mutant p53 degradation. STUDY DESIGN AND METHODS: Different mutant p53 cell lines were used to evaluate the anticancer activity of KBA01. MTT assay, colony formation assay and cell cycle analysis were performed to examine the effect of KBA01 on cancer cell proliferation. Western blotting and qPCR were used to investigate effects of depleting mutant p53, and a ubiquitination assay was used to determine mutant p53 ubiquitin levels after cells were treated with the compound. Co-IP and small interfering RNA assays were used to explore the effects of KBA01 on the interaction of Hsp90 with mutant p53. RESULTS: The triterpenoid alkaloid KBA01 can induce G2/M cell cycle arrest and the apoptosis of HT29 colon cancer cells. KBA01 decreases the stability of DNA contact mutant p53 proteins through the proteasomal pathway with minimal effects on p53 mutant protein conformation. Moreover, KBA01 enhances the interaction of mutant p53 with Hsp70, CHIP and MDM2, and knocking down CHIP and MDM2 stabilizes mutant p53 levels in KBA01-treated cells. In addition, KBA01 disrupts the HSF1-mutant p53-Hsp90 complex and releases mutant p53 to enable its MDM2- and CHIP-mediated degradation. CONCLUSION: Our study reveals that KBA01 depletes mutant p53 protein in a chaperone-assisted ubiquitin/proteasome degradation pathway in cancer cells, providing insights into potential strategies to target mutant p53 tumours.