Glycoside Esters Research Articles

Comparative Proteomic Analysis Reveals the Effect Mechanisms of Glucose on the Biomass and Phenolic Glycoside Esters Synthesis Activity of Candida Parapsilosis ACCC 20221 Whole-Cell Catalyst.

A new Candida parapsilosis ACCC 20221 (C. parapsilosis ACCC 20221) whole-cell catalyst with a high phenolic glycoside esters synthesis activity and large biomass was obtained after culture with glucose. The possible mechanisms were revealed by using comparative proteomics. It found the expression of proteins involved in post-translational modification, protein turnover, and chaperone, and RNA processing and modification was upregulated, which ensured the metabolic balance and accurate translation, correct folding, and post-translational modification of proteins, thus enhancing the production of lipases in C. parapsilosis ACCC 20221 cultured with glucose. Moreover, the glycolysis pathway, tricarboxylic acid cycle, and fatty acids synthesis were enhanced, while the β-oxidation of fatty acids was weakened in C. parapsilosis ACCC 20221 cells cultured with glucose, which led to an increase in energy generation and cell membrane synthesis; thus, large biomass was obtained. In addition, CCE40476.1 and CAC86400.1, which were likely to exert arbutin esters synthesis activity in C. parapsilosis ACCC 20221, were screened, and it was found that vinyl propionate could easily enter the catalytic pocket of CCE40476.1 and form hydrogen bonding interactions with Leu191 and Ser266.

Improving physicochemical characteristics and cytotoxicity of baicalin esters by liposome encapsulation

The instability of ester bonds, low water solubility, and increased cytotoxicity of flavonoid glycoside esters significantly limit their application in the food industry. Therefore, the present study attempted to resolve these issues through liposome encapsulation. The results showed that baicalin butyl ester (BEC4) and octyl ester (BEC8) have higher encapsulation and loading efficiencies and lower leakage rate from liposomes than baicalin. FTIR results revealed the location of BEC4 and BEC8 in the hydrophobic layer of liposomes, which was different from baicalin. Additionally, liposome encapsulation improved the water solubility and stability of BEC4 and BEC8 in the digestive system and PBS but significantly reduced their cytotoxicity. Furthermore, the release rate of BEC4 and BEC8 from liposomes was lower than that of baicalin during gastrointestinal digestion. These results indicate that liposome encapsulation alleviated the negative effects of fatty chain introduction into flavonoid glycosides.

Pitsubcosides M−S: Novel antibacterial cadinane sesquiterpenoid glycoside esters from Pittosporum subulisepalum

A previous study on Pittosporum subulisepalum led to twelve novel, antibacterial eudesmane sesquiterpenoid glycoside esters (ESGEs). To continue the work on P. subulisepalum, this study focused on the exploration of cadinane sesquiterpenoid glycoside esters (CSGEs) with antibacterial activities and their mechanism of actions. Chemical exploration of the ethyl acetate (EtOAc) soluble phase of the leaves and stems of P. subulisepalum resulted in seven previously unreported cadinane sesquiterpenoid glycosides (CSGs), pitsubcosides M-S (1 −7), along with three known analogs. Based on one- and two-dimensional NMR (1D and 2D NMR), HRESIMS, and experimental/calculated electronic circular dichroism (ECD) spectroscopic analyses, the structures of the isolated compounds were elucidated. The novelty of these sesquiterpenoid glycosides was characterized by the highly esterified glycoside moieties. Compounds 1 − 5 exhibited marked inhibitory effects on Bacillus subtilis, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Bacillus cereus, Erwinia carotovora, and Pseudomonas syringae pv. actinidiae with the minimum inhibitory concentration (MIC) values of 3.13 μM− 50 μM. Of these, compounds 1 − 2 displayed significant antibacterial activity against B. subtilis (MIC = 3.13 and 6.25 μM). The live masses and the biofilms of B. subtilis were quantified after being treated with compounds 1 and 2. The preliminary antibacterial mechanism was revealed as to prevent bacterial biofilm formation or to destroy the formed cell membranes. These results indicated that CSGEs from P. subulisepalum are potential antibacterial lead agents.

Pitsubcosides A-L, highly esterified eudesmane sesquiterpenoid glycosides with antibacterial activity from Pittosporum subulisepalum and their mechanism.

Plants from the genus Pittosporum are traditionally used as antibacterial, antifungal and antiviral agents. A bioassay evaluation of the extract of Pittosporum subulisepalum revealed antibacterial activity. This study focused on the discovery of the antibacterial metabolism in P. subulisepalum, as well as the modes of action of its active components. A chemical investigation of an ethyl acetate (EtOAc) extract of the aerial parts of P. subulisepalum led to the isolation of 12 previously undescribed eudesmane sesquiterpenoid glycoside esters (ESGEs), pitsubcosides A-L (1-12). Their structures were elucidated by extensive spectroscopic analysis, including one- and two-dimensional NMR, high-resolution electrospray ionization mass spectrometry, electronic circular dichroism spectra and single-crystal X-ray crystallography analysis or by comparing with authentic samples. The new ESGEs were characterized by their highly esterified glycoside moieties. Among them, compounds 1-3, 5 and 8 showed a moderate inhibitory effect against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Bacillus cereus, Bacillus subtilis, Pseudomonas syringae pv. actinidiae (Psa) and Erwinia carotovora with minimum inhibitory concentrations (MICs) ranging from 3.13 to 100 μm. Among them, compounds 3 and 5 showed remarkable antibacterial activity against S. aureus and Psa with MIC values of 6.25 and 3.13 μm, respectively. Live bacterial mass and the biofilms of S. aureus and Psa were quantified using methyl tetrazolium and crystal violet assays. Fluorescence microscopy and scanning electron microscopy experiments revealed an antibacterial mechanism of cell membrane architectural disruption. The results suggest that ESGEs possess great potential for the development of antibacterial agents to control plant pathogens. © 2023 Society of Chemical Industry.

Effect of Ethanol Solution Concentration in the Extraction Process of Centella asiatica L. Bioactive Components Using Microwave-Assisted Extraction (MAE) Method

The Pegagan plant has a scientific name in the form of Centella asiatica L. which is included in the Centella genus, Apiaceae family, and kingdom Plantae. Pegagan (Centella asiatica L.) has distinctive bioactive components, namely triterpene ester glycoside compounds in the form of asiaticoside and madecassoside, and triterpene group compounds in the form of Asiatic acid and madecassic acid. In this study, the extraction of bioactive components from pegagan was carried out using the Microwave-Assisted Extraction (MAE) method and will study the effect of ethanol solvent concentration in the extraction of bioactive compounds. Analysis of the extracted bioactive content was carried out by analyzing the total phenol content using the Folin-Ciocalteau reagent and ANOVA analysis. The results obtained from the study were in the form of total phenol content as an indication of the presence of bioactive compounds, namely at operating conditions of 450 watts of power, 50% ethanol concentration with a radiation time of 15 minutes which resulted in a total phenol content of 21.9244 mg AGE/g sample. In the ANOVA analysis with ethanol solvent, variables that gave a significant response to the total phenol content were microwave power, radiation time, and ethanol concentration with an R-square value of 95.31%. The effect of ethanol concentration on the total phenol content produced, namely the concentration of pure ethanol solvent will produce extracts with the smallest total phenol content, the effect of extraction time on total phenol content, namely the longer extraction time will increase the total phenol content. Maximum total phenol content using ethanol solvent that is, at operating conditions of 450 watts of power, 10% ethanol concentration with a radiation time of 15 minutes which resulted in a total phenol content of 520 mg AGE/g sample.

Characterization of Sideritis clandestina subsp. peloponnesiaca Polar Glycosides and Phytochemical Comparison to Other Mountain Tea Populations.

Sideritis clandestina (Bory & Chaub.) Hayek subsp. peloponnesiaca (Boiss. & Heldr.) Baden (SCP) is endemic to the mountains of the Northern Peloponnese (Greece). This and other Sideritis taxa, collectively known as mountain tea, are widely ingested as beverages for refreshment or medicinal purposes. We describe a methodology for the characterization of SCP. Four iridoid glycosides (monomelittoside, melittoside, ajugoside, and 7-O-acetyl-8-epiloganic acid), two phenolic acid glycosides (vanillic and salicylic acid glycosides), and three caffeoyl ester glycosides (chlorogenic acid, verbascoside, and isoverbascoside) were isolated from SCP for the first time. We used ultrasound-assisted extraction of 3 g of plant material to produce petroleum ether and aqueous extracts, which we then analyzed using GC/MS and LC/MS. This was applied to eight samples from four different taxa. In total, 70 volatile and 27 polar metabolites were determined. The S. clandestina samples had a lower phenolic content and weaker antioxidant properties than S. raeseri and S. scardica. However, S. clandestina ssp. clandestina seemed to be the most aromatic taxon, with almost double the number of volatiles as the others. Τhis study could contribute to authentication and chemotaxonomic studies of Sideritis taxa.

Further sesquiterpenoids from Pittosporum qinlingense and their anti-inflammatory activity

Four new sesquiterpenoid glycoside esters, Pitqinlingoside N-Q (1–4), together with eleven known metabolites (5–15), were isolated from 95% EtOH extract of the twigs, fruits and leaves of P. qinlingense. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses, including IR, UV, HRMS, NMR and electronic circular dichroism spectra. Unusal glycoside esters are characterized by the presence of polyacylated β-D-fucopyranosyl and β-d-glucopyranosyl units. Pitqinlingoside N (1), O (2), P (3), boscialin (5) and arvoside C (6) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC50 values ranging from 1.58 to 28.74 μM. Structure-activity relationships of the isolated compounds are discussed.

Four pairs of tautomers from rhizomes of Acorus calamus and fruits of Cornus officinalis

A pair of new guaiane-type sesquiterpene tautomers (1) was isolated from rhizomes of Acorus calamus. Meanwhile, three pairs of known compounds, including a pair of dihydroflavone glycoside tautomers (2), a pair of 4-hydroxybenzoic acid ester glycoside tautomers (3), as well as a pair of secoiridoid glycoside tautomers (4) were isolated from fruits of Cornus officinalis. Their structures were elucidated by extensive spectroscopic and computational methods. Furthermore, the tautomeric mechanisms were discussed.

Comparison of Pegagan (Centella asiatica (L.)) Extraction with Ultrasound-Assisted Extraction and Microwave-Assisted Extraction Methods Using Response Surface Methodology

Pegagan (Centella asiatica (L.)) is one of the herbaceous plants that grow, and flowers throughout the year. Pegagan has been used for hundreds of years, especially in the dermatology, and cosmetology industries. Pegagan (Centella asiatica (L.)) has distinctive bioactive components, namely triterpene ester glycoside compounds in the form of asiaticoside, and madecoside as well as triterpene group compounds in the form of asiatic acid, and madecasic acid. There are various extraction methods to produce the following compounds namely, conventional extraction methods, and modern extraction methods. The two methods have differences in the results obtained. Therefore, the difference in the extraction method will determine the result of the difference in the levels of a compound. So that this research was carried out on the effect of Pegagan (Centella asiatica (L.)) extraction using a comparison of the Microwave-Assisted Extraction (MAE), and Ultrasound-Assisted Extraction (UAE) methods on the total phenol content in the Pegagan (Centella asiatica (L.)) extracted. Analysis of the extracteded bioactive content was carried out by analyzing the total phenol content using the Folin-Ciocalteau reagent method and analyzing the data through the Analysis of Response Surface Design expert 11 to see the significance of the research variables. The results obtained from the study are in the form of a comparison of the optimal conditions for the total phenol content, namely, the comparison between the UAE, and MAE methods for Centella asiatica (L.). extracted with ethanol solvent which is more optimal by using the MAE method because in a short time it can produce 1130.7882 mg.

Structurally Diverse Sesquiterpenoid Glycoside Esters from Pittosporum qinlingense with Anti-neuroinflammatory Activity

Thirteen new sesquiterpenoid glycoside esters, including 11 aromadendrane-type compounds, pitqinlingosides A-K (1-11), one cadinane-type compound, pitqinlingoside L (12), and one eudesmane-type compound, pitqinlingoside M (13), together with seven known analogues (14-20) were isolated from the twigs, fruits, and leaves of Pittosporum qinlingense. Structures were elucidated by analysis of spectroscopic data, gas chromatography mass spectrometry (GC-MS), and chemical methods. The absolute configuration was confirmed by single-crystal X-ray crystallography analysis or electronic circular dichroism spectra. Unusual glycoside esters are characterized by the presence of polyacylated β-d-fucopyranosyl, β-d-glucopyranosyl, and β-d-xylopyranosyl units. Pitqinlingosides A (1), B (2), D (4), and F (6), pittosporanoside A1 acetate (14), and pittosporanoside A1 (16) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC50 values ranging from 0.95 to 24.12 μM. Structure-activity relationships of the isolated compounds are discussed.

Six new triterpenoids from the root of Potentilla reptans and their cardioprotective effects in silico

Tormentic acid ester glucosides derivatives (1, 2 and 4), 3-oxoursane ester glycoside (3) and 11-methoxy-ursane ester glycosides (5, 6) as six new triterpenoids, along with catechin were isolated from the ethyl acetate fraction of Potentilla reptans root (Et) methanolic extract. The structures of the compounds were elucidated by 1D, 2D NMR, IR and MS spectroscopy. Additionally, isolated triterpenoid compounds (1–6) and catechin were evaluated for their cardioprotective effects via glycogen synthase kinase 3β (GSK-3β) and glucocorticoid regulated kinase-1 (SGK1) protein kinase inhibition by Molecular Docking. Compound 1 and catechin (compound 7) exhibited significant inhibitory effects against GSK-3β and SGK1 protein kinases with a binding energy value −9.1 and −8.8 kcal/mol, respectively. Hence, Et can be a suitable natural candidate to protect cardiomyocytes injury.

Chemical characterization of a PD-1/PD-L1 inhibitory activity fraction of the ethanol extract from Gymnadenia conopsea

Searching for PD-1/PD-L1 inhibitor from medicinal plants has become a potential method to discover small molecular cancer immunotherapy drugs. Using PD-1/PD-L1 inhibitory activity assay in vitro, a bioactive fraction was obtained from the ethanol extract of Gymnadenia conopsea. A sensitive UPLC-HRMS/MS method was established for the rapid screening and identification of compositions from bioactive fraction. Based on the characteristic fragmentation patterns of standards analysis and extracted ion chromatogram (EIC) method, 46 compounds were rapidly screened and identified (including 35 succinic acid ester glycosides and 11 other compounds), among which 17 compounds were tentatively identified as new compounds.

Three new ester glycosides with cytotoxic activity from the seeds of Caesalpinia sappan

Three new ester glycosides, named as Caesateroside A (1), Caesateroside B (2) and Caesateroside C (3) were obtained from the seeds of Caesalpinia sappan. The new structures of compounds 1-3 were elucidated by analyzing their 1 D NMR, 2 D NMR and HR-ESI-MS spectra. Compounds 1-3 showed weak-moderate cytotoxicity against Hela and HepG-2 human cancer cell lines.

New sesquiterpene glycoside ester with antiprotozoal activity from the flowers of Calendula officinalis L

Continued chromatographic investigation of Calendula officinalis flowers led to the isolation of two sesquiterpenes, including one new, viridiflorol-10-O-β-quinovopyranoside-2`-O-(3``-methyl-2``-pentenoate) (1), along with a previously reported compound viridiflorol-10-O-β-fucopyranoside-2`-O-(3``-methyl-2``-pentenoate) (2). The new compound 1 was tested for antiprotozoal activity against Leishmania donovani Amastigote/THP1 and Trypanosoma brucei and it showed IC50 values of 3.57 and 7.84 µg/mL, respectively, while compound 2 exhibited no activity at the highest concentration tested 10 µg/mL.

Rapid Characterizaiton of Chemical Constituents of the Tubers of Gymnadenia conopsea by UPLC-Orbitrap-MS/MS Analysis.

Gymnadenia conopsea R. Br. is a traditional Tibetan medicinal plant that grows at altitudes above 3000 m, which is used to treat neurasthenia, asthma, coughs, and chronic hepatitis. However, a comprehensive configuration of the chemical profile of this plant has not been reported because of the complexity of its chemical constituents. In this study, a rapid and precise method based on ultra-high performance liquid chromatography (UPLC) combined with an Orbitrap mass spectrometer (UPLC–Orbitrap–MS/MS) was established in both positive- and negative-ion modes to rapidly identify various chemical components in the tubers of G. conopsea for the first time. Finally, a total of 91 compounds, including 17 succinic acid ester glycosides, 9 stilbenes, 6 phenanthrenes, 19 alkaloids, 11 terpenoids and steroids, 20 phenolic acid derivatives, and 9 others, were identified in the tubers of G. conopsea based on the accurate mass within 3 ppm error. Furthermore, many alkaloids, phenolic acid derivates, and terpenes were reported from G. conopsea for the first time. This rapid method provides an important scientific basis for further study on the cultivation, clinical application, and functional food of G. conopsea.

GC-MS and HPLC-ESI-MS-MS Characterization of Sanchezia oblonga (Acanthaceae) Extracts

The genus Sanchezia (Acanthaceae) comprises neotropical herbs and shrubs with showy flowers. Sanchezia oblonga (syn. S. nobilis) is a shrub of the rainforests of central and south America. The ethanolic extracts of leaves and stems from S. oblonga were analyzed by GC-EI-MS and RPHPLC-DAD-ESI-MS/MS. Fatty acids (free and esterified) and phytosterols were detected by the former method. Benzyl alcohol glycosides (21 and 25), sinapic acid glycoside esters (29 and 31), ethyl rosmarinate (24), sinapic acid-O-glucoside (28), dihydrosinapic acid-O-glucoside (26), catechin-O-arabinoside (36), in addition to flavonols glycosides (23, 32, 33 and 35) and rosmarinic acid-3’-O-glucoside (34) were detected by RPHPLC-DAD-ESI-MS/MS. Three new compounds, detected only in leaves, were tentatively identified as phenylpropane glyceride derivatives 1-O-coumaroyl-2-hydroxy propanal (20) and 1-O-coumaroyl-2-O-glycosyl propanal (22, 30). Compounds 20, 22 and 30 from S. oblonga are similar with phenylpropane glycerides present in red sorghum (Sorghum bicolor L. (Moench) and Lilium longiflorum Thunb. It is noteworthy that S. oblonga could be used in cooking as a complement after more detailed studies. Sorghum grain foods exhibit potential health benefits against chronic diseases related to over-nutrition. Lilium longiflorum possess flower buds and bulbs that are used for both culinary and medicinal purposes in many parts of the world. Studies on chemical composition and biological activity of the genus Sanchezia are scarce. The presence of phytosterols and flavonol glycosides were recently reported in leaves from this species. However, the chemical profile of the extracts analyzed in this work differs from that previously reported for aerial parts of S. nobilis (sin. S. oblonga). Further studies, including statistical methods, such as principal component analysis and hierarchical cluster analysis will be needed to evaluate chemical markers for this species.

Chemical constituents of Trillium tschonoskii Maxim.

A new fatty acid-spirostan steroid glycoside ester, a new cholestane glycoside and a new stilbene trimer, along with three known steroidal saponins, were isolated from the 70% EtOH extract of the roots and rhizomes of Trillium tschonoskii Maxim. The structure of isolated compounds was elucidated by spectroscopic analysis. Compound 1–6 were assessed for their cytotoxicity against cancer cell lines (MCF-7, HCT-116, DU-145, SGC-7901, MCF-7/ADR, K562/ADR), and the result showed that compound 4 was highly toxic to six human tumor cell lines.

2-Deoxyglycosylation towards more effective and bioavailable neuroprotective molecules inspired by nature

Abstract The neuroprotective role of natural polyphenols is well established but phenolics poor water solubility affects their bioavailability and bioactivity. Aiming to overcome this issue, we were encouraged to investigate the 2-deoxyglycosylation of natural or nature inspired neuroprotective molecules, using glycals as easily accessed glycosyl donors. This robust methodology allowed the generation of a set of new resveratrol and caffeic acid ester glycosides, envisioning more effective and bioavailable compounds. Resveratrol 2-deoxyglycosides were more effective at protecting the neuronal cells from peroxide-induced cytotoxicity than resveratrol itself, while the caffeic acid ester glycoside also showed extraordinary neuroprotection activity. Coefficient partition measurements demonstrated the moderate lipophilicity of resveratrol glycosides, which Log D values are typical of a central nervous system (CNS) drug and ideal for blood-brain barrier (BBB) penetration. Passive permeation assessed by the parallel artificial membrane permeability assay (PAMPA) revealed that 2,6-dideoxy-l-arabino-hexopyranosides were more effective than 2-deoxy-d-arabino-hexopyranosides. The lack of toxicity of the neuroprotective glycosides and their promising physicochemical properties revealed the usefulness of sugar coupling towards the modulation of natural product properties and bioactivity.

In-depth analysis of crocetin ester glycosides from dried/processed stigmas of Crocus sativus L. by HPLC-ESI-MSn (n = 2, 3).

Saffron stigmas from Crocus sativus L. (Iridaceae) are used as a drug in folk medicine, as a food additive and as a dying agent for at least 3500years. Despite this long-term use the chemical composition of saffron seems still to be not fully known. An analytical strategy for detailed investigations of aqueous saffron extract is developed based on reverse-phase high-performance liquid chromatography electrospray ionisation (HPLC-ESI) multistage mass spectrometry (MSn ) for crocins. Commercially available stigmas are analysed by reverse-phase HPLC in combination with ESI/three-dimensional (3D)-ion trap mass spectrometry (MS) and MSn (n=2 and 3). Sodium chloride is added to the analyte solution ready for injection to promote abundant [M+Na]+ adduct ions of crocins, being ideal precursor ions for low-energy collision-induced dissociation (CID)-MS2/3 . This strategy allows the detailed structural elucidation of known as well as previously unknown crocin derivatives (molecular mass of the aglycon, oligosaccharide chain length and linkage determination). The two isomeric trisaccharide substituents neapolitanose and gentiotriose are distinguished based on linkage-specific cross-ring cleavage for the first time. Furthermore, crocins containing up to six hexose units are also observed. Five novel crocin ester glycosides shifted by a mass difference of -40Da indicate the presence of the here newly described C17 -aglycon, termed norcrocetin (crocetin=C20 ). These findings indicate the action of at least two different carotenoid cleavage dioxygenases (CCD2 and tentatively CCD4) during biosynthesis of this new bis-apocarotenoid aglycon (norcrocetin) and the existence of even higher glycosylated crocin derivatives at trace level.

Two new terpenoid ester glycosides from the twigs of Litsea cubeba

A new sesquiterpenoid ester glycoside (1) and a new monoterpenoid ester glycoside (2) have been isolated from an ethanol extract of the twigs of Litsea cubeba. Their structures were elucidated by extensive 1D- and 2D-NMR experiments, and the absolute configurations were determined by chemical methods, specific rotation, and a combination of experimental and theoretically calculated electronic circular dichroism spectra. Compound 1 exhibited selective cytotoxicity against A549 and HCT-8 cell lines with the IC50 values of 8.9 and 9.6 μM, respectively.