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Centella asiatica is an ethnomedicinal herbaceous species that grows abundantly in tropical and sub‐tropical regions of China, India, South‐Eastern Asia and Africa. It is a popular nutraceutical that is employed in various forms of clinical and cosmetic treatments. C. asiatica extracts are reported widely in Ayurvedic and Chinese traditional medicine to boost memory, prevent cognitive deficits and improve brain functions. The major bioactive constituents of C. asiatica are the pentacyclic triterpenoid glycosides, asiaticoside and madecassoside, and their corresponding aglycones, asiatic acid and madecassic acid. Asiaticoside and madecassoside have been identified as the marker compounds of C. asiatica in the Chinese Pharmacopoeia and these triterpene compounds offer a wide range of pharmacological properties, including neuroprotective, cardioprotective, hepatoprotective, wound healing, anti‐inflammatory, anti‐oxidant, anti‐allergic, anti‐depressant, anxiolytic, antifibrotic, antibacterial, anti‐arthritic, anti‐tumour and immunomodulatory activities. Asiaticoside and madecassoside are also used extensively in treating skin abnormalities, burn injuries, ischaemia, ulcers, asthma, lupus, psoriasis and scleroderma. Besides medicinal applications, these phytocompounds are considered cosmetically beneficial for their role in anti‐ageing, skin hydration, collagen synthesis, UV protection and curing scars. Existing reports and experimental studies on these compounds between 2005 and 2022 have been selectively reviewed in this article to provide a comprehensive overview of the numerous therapeutic advantages of asiaticoside and madecassoside and their potential roles in the medical future.

Plants typically contain a broad spectrum of flavonoids in varying concentrations. As a rule, several flavonoid classes occur in parallel, and, even for a single flavonoid, divergent glycosylation patterns are frequently observed, many of which are not commercially available. This can be challenging in studies in which the distribution between flavonoid classes, or features that are not affected by glycosylation patterns, are adressed. In addition, hydrolysis simplifies the quantification process by reducing peak interferences and improving the peak intensity due to the accumulation of the respective aglycone. Effective removal of glycose moieties can also be relevant for technological applications of flavonoid aglycones. Herein, we present a fast and reliable method for the enzymatic hydrolysis glycosides from plant extracts using the commercial enzyme mix snailase, which provided the highest aglycone yields across all investigated flavonoids (aurones: leptosidin, maritimetin, sulfuretin; chalcones: butein, lanceoletin, okanin, phloretin; dihydroflavonols: dihydrokaempferol; flavanones: eriodictyol, hesperetin; flavones: acacetin, apigenin, diosmetin, luteolin; flavonols: isorhamnetin, kaempferol, myricetin, quercetin; isoflavones: biochanin A, formononetin, genistein) from methanolic extracts of nine plants ( Bidens ferulifolia, Coreopsis grandiflora, Fagus sylvatica, Malus × domestica, Mentha × piperita, Petunia × hybrida, Quercus robur, Robinia pseudoacacia , and Trifolium pratense ) in comparison to four other enzymes (cellobiase, cellulase, β-glucosidase, and pectinase), as well as to acidic hydrolysis by hydrochloric acid.

With climate change, the pressure on tree breeding to provide varieties with improved resilience to biotic and abiotic stress is increasing. As such, pest resistance is of high priority but has been neglected in most tree breeding programs, given the complexity of phenotyping for these traits and delays to assess mature trees. In addition, the existing genetic variation of resistance and its relationship with productivity should be better understood for their consideration in multitrait breeding. In this study, we evaluated the prospects for genetic improvement of the levels of acetophenone aglycones (AAs) in white spruce needles, which have been shown to be tightly linked to resistance to spruce budworm. Furthermore, we estimated the accuracy of genomic selection (GS) for these traits, allowing selection at a very early stage to accelerate breeding. A total of 1,516 progeny trees established on five sites and belonging to 136 full‐sib families from a mature breeding population in New Brunswick were measured for height growth and genotyped for 4,148 high‐quality SNPs belonging to as many genes along the white spruce genome. In addition, 598 trees were assessed for levels of AAs piceol and pungenol in needles, and 578 for wood stiffness. GS models were developed with the phenotyped trees and then applied to predict the trait values of unphenotyped trees. AAs were under moderate‐to‐high genetic control (h2: 0.43–0.57) with null or marginally negative genetic correlations with other traits. The prediction accuracy of GS models (GBLUP) for AAs was high (PAAC: 0.63–0.67) and comparable or slightly higher than pedigree‐based (ABLUP) or BayesCπ models. We show that AA traits can be improved and that GS speeds up the selection of improved trees for insect resistance and for growth and wood quality traits. Various selection strategies were tested to optimize multitrait gains.

This review presents the comprehensive knowledge about the bidirectional relationship between polyphenols and the gut microbiome. The first part is related to polyphenols’ impacts on various microorganisms, especially bacteria, and their influence on intestinal pathogens. The research data on the mechanisms of polyphenol action were collected together and organized. The impact of various polyphenols groups on intestinal bacteria both on the whole “microbiota” and on particular species, including probiotics, are presented. Moreover, the impact of polyphenols present in food (bound to the matrix) was compared with the purified polyphenols (such as in dietary supplements) as well as polyphenols in the form of derivatives (such as glycosides) with those in the form of aglycones. The second part of the paper discusses in detail the mechanisms (pathways) and the role of bacterial biotransformation of the most important groups of polyphenols, including the production of bioactive metabolites with a significant impact on the human organism (both positive and negative).

Phenolics and extracted phenolic compounds of Scots pine ( Pinus sylvestris ) and Norway spruce ( Picea abies ) show antibacterial activity against several bacteria. The majority of phenolic compounds are stilbenes, flavonoids, proanthocyanidins, phenolic acids, and lignans that are biosynthesized in the wood through the phenylpropanoid pathway. In Scots pine ( P. sylvestris ), the most abundant phenolic and antibacterial compounds are pinosylvin-type stilbenes and flavonol- and dihydroflavonol-type flavonoids, such as kaempferol, quercetin, and taxifolin and their derivatives. In Norway spruce ( P. abies ) on the other hand, the main stilbene is resveratrol and the major flavonoids are quercetin and myricetin. In general, when the results from the literature regarding the activities of flavonoid glycosides and their aglycones against a total of twenty-one microorganisms are summarized, it was found that phenolic glycosides are less active than the corresponding aglycones, although a number of exceptions are also known. The aglycones in plants respond to various kinds of biotic stress. Synergistic effects between aglycones and their glycosides have been observed. Minimum inhibition concentrations of below 10 mg L −1 against bacteria have been reported for gallic acid, apigenin, and several methylated and acylated flavonols present in these industrially important trees. In general, the phenolic compounds are more active against Gram-positive bacteria, but apigenin is reported to exhibit strong activity against Gram-negative bacteria. The present review lists some of the biosynthesis pathways for the antibacterial phenolic metabolites found in Scots pine ( P. sylvestris ) and Norway spruce ( P. abies ). The antimicrobial activity of the compounds is collected and compared to gather information about the most effective secondary metabolites.

Flavonoids are well known for their extensive health benefits. However, few studies compared the differences between flavonoid O-glycoside and C-glycoside. In this work, flavonoid O-glycoside (isoquercitrin), C-glycoside (orientin), and their aglycones (quercetin and luteolin) were chosen to compare their differences on antioxidant activities and metabolism during in vitro digestion and in vivo. In vitro digestion, the initial antioxidant activity of the two aglycones was very high; however, they both decreased more sharply than their glycosides in the intestinal phase. The glycosidic bond of flavonoid O-glycoside was broken in the gastric and intestinal stage, while the C-glycoside remained unchanged. In vivo, flavonoid O-glycoside in plasma was more elevated than C-glycoside on the antioxidant activity; however, flavonoid C-glycoside in urine was higher than O-glycoside. These results indicate that differences of flavonoid glycosides and their aglycones on antioxidant activity are closely related to their structural characteristics and metabolism in different samples. Aglycones possessed higher activity but unstable structures. On the contrary, the sugar substituents reduced the activity of flavonoids while improving their stability and helping to maintain antioxidant activities after digestion. Especially the C-glycoside was more stable because the stability of the C–C bond is higher than that of the C–O bond, which contributes to the difference between flavonoid O-glycoside and C-glycoside on the absorption and metabolism in vivo. This study provided a new perspective for comparing flavonoid O-glycoside, flavonoid C-glycoside, and their aglycones on their structure–activity relationship and metabolism.

Flavonoids possess diverse bioactivity and potential medicinal values. Glycosylation of flavonoids, coupling flavonoid aglycones and glycosyl groups in conjugated form, can change the biological activity of flavonoids, increase water solubility, reduce toxic and side effects, and improve specific targeting. Therefore, it is desirable to synthesize various flavonoid glycosides for further investigation on their medicinal values. Compared with chemical glycosylations, biotransformations catalyzed by uridine diphospho-glycosyltransferases provide an environmentally friendly way to construct glycosidic bonds without repetitive chemical synthetic steps of protection, activation, coupling, and deprotection. In this review, we will summarize the existing knowledge on the biotechnological glycosylation reactions either in vitro or in vivo for the synthesis of flavonoid O- and C-glycosides and other rare analogs.Key points• Flavonoid glycosides usually show improved properties compared with their flavonoid aglycones.• Chemical glycosylation requires repetitive synthetic steps and purifications.• Biotechnological glycosylation reactions either in vitro or in vivo were discussed.• Provides representative synthetic examples in detail.

The medicinal herb Centella asiatica (L.) Urban known as gotu kola has been reported to exhibit a wide range of pharmacological activities. In particular, a significant body of scientific research exists on the therapeutic properties of preparations of C. asiatica or its triterpenes in the treatment of skin diseases. The present study is aimed to provide a comprehensive overview of the beneficial effects of C. asiatica on skin diseases. Peer-reviewed articles on the potent dermatological effects of C. asiatica were acquired from PubMed, Web of Science, Scopus, ScienceDirect, and SciFinder. This review provides an understanding of pharmacological studies which confirm the potent dermatological effects and underlying molecular mechanisms of C. asiatica. This medicinal plant and its triterpenes include asiaticoside, madecassoside, and their aglycones, asiatic acid and madecassic acid. These compounds exert therapeutic effects on dermatological diseases such as acne, burns, atopic dermatitis, and wounds via NF-κB, TGF-β/Smad, MAPK, Wnt/β-catenin, and STAT signaling in in vitro and in vivo studies. However, additional rigorously controlled long-term clinical trials will be necessary to confirm the full potential of C. asiatica as a therapeutic agent.

Vanilla flavor is derived from the cured fruits of two orchid species Vanilla planifolia and V. × tahitensis. About twenty other Vanilla species are also credited with scented fruits, but very little is known about their aromatic features. We investigated the aromatic compound content of the ripe fruits of 30 vanilla accessions obtained from eight species and three hybrids. Glucovanillin plus six phenolic and one anisic aglycones, extracted after enzymatic hydrolysis, were quantified by High-Performance Liquid Chromatography and Ultra-Violet detection. The analysis of the aromatic contents and the principal components showed clear-cut differences in the aromatic content of the species and varieties studied. The total content of aromatic compounds separated the three species most distantly related to V. planifolia, namely V. lindmaniana, V. crenulata and V. imperialis, from the other species notably by the absence of vanillin potential and a very low total aromatic potential (< 0.45% w/w dry matter). A clear gradient was observed between the different genotypes of V. planifolia, in particular for the total aromatic content (range 3.07–5.00% dry weight) and the vanillin potential (1.80–4.58%). Among all the analyzed samples, the greatest vanillin potential was observed in a V. planifolia x V. × tahitensis hybrid (7.46%). Anisyl alcohol was not detected in any of the 13 V. planifolia varieties but was detected in most of its close relatives such as V. sotoarenasii, V. bahiana, V. tahitensis, and V. pompona. Our data evidenced the very contrasting aromatic profiles of vanilla fruits, even among very close genotypes.

We report to use the main protease (M pro ) of SARS-Cov-2 to screen plant flavan-3-ols and proanthocyanidins. Twelve compounds, (–)-afzelechin (AF), (–)-epiafzelechin (EAF), (+)-catechin (CA), (–)-epicatechin (EC), (+)-gallocatechin (GC), (–)-epigallocatechin (EGC), (+)-catechin-3-O-gallate (CAG), (–)-epicatechin-3-O-gallate (ECG), (–)-gallocatechin-3-O-gallate (GCG), (–)-epigallocatechin-3-O-gallate (EGCG), procyanidin A2 (PA2), and procyanidin B2 (PB2), were selected for docking simulation. The resulting data predicted that all 12 metabolites could bind to M pro . The affinity scores of PA2 and PB2 were predicted to be −9.2, followed by ECG, GCG, EGCG, and CAG, −8.3 to −8.7, and then six flavan-3-ol aglycones, −7.0 to −7.7. Docking characterization predicted that these compounds bound to three or four subsites (S1, S1′, S2, and S4) in the binding pocket of M pro via different spatial ways and various formation of one to four hydrogen bonds. In vitro analysis with 10 available compounds showed that CAG, ECG, GCG, EGCG, and PB2 inhibited the M pro activity with an IC 50 value, 2.98 ± 0.21, 5.21 ± 0.5, 6.38 ± 0.5, 7.51 ± 0.21, and 75.3 ± 1.29 μM, respectively, while CA, EC, EGC, GC, and PA2 did not have inhibitory activities. To further substantiate the inhibitory activities, extracts prepared from green tea (GT), two muscadine grapes (MG), cacao, and dark chocolate (DC), which are rich in CAG, ECG, GAG, EGCG, or/and PB2, were used for inhibitory assay. The resulting data showed that GT, two MG, cacao, and DC extracts inhibited the M pro activity with an IC 50 value, 2.84 ± 0.25, 29.54 ± 0.41, 29.93 ± 0.83, 153.3 ± 47.3, and 256.39 ± 66.3 μg/ml, respectively. These findings indicate that on the one hand, the structural features of flavan-3-ols are closely associated with the affinity scores; on the other hand, the galloylation and oligomeric types of flavan-3-ols are critical in creating the inhibitory activity against the M pro activity.