Resin glycosides from Ipomoea wolcottiana as modulators of the multidrug resistance phenotype in vitro

Four new resin glycosides, calyhedins VII-X, from the rhizomes of Calystegia hederacea

Four new resin glycosides with macrolactone structures (jalapins), namely, calyhedins VII (1)-X (4), were isolated from the rhizomes of Calystegia hederacea Wall. (Convolvulaceae). The structures of 1-4 were determined based on spectroscopic data. They were classified into three ring types: a 27-membered ring (1), a 22-membered ring (2, 3), and a 23-membered ring (4). Their sugar moieties were partially acylated using five organic acids, including (E)-2-methylbut-2-enoic acid, 2S-methylbutyric acid, and 2 R-methyl-3R-hydroxybutyric acid. Compound 4 was the first genuine resin glycoside with calyhedic acid F as the glycosidic acid component. Additionally, the cytotoxic activities of 1, 2, and 4 towards HL-60 human promyelocytic leukaemia cells were evaluated. All compounds demonstrated almost the same activity as the positive control, cisplatin.

Resin Glycosides from Convolvulaceae Family: An Update

Resin glycoside is a type of secondary metabolite isolated commonly from the Convolvulaceae family. It consists of oligosaccharides conjugated to organic acids with a larger percentage having a macrocyclic structure. The resin glycosides reported in this review is classified mostly based on the number of sugar units constructing the structure, which is correlated to the biological properties of the compounds. According to preliminary reviews, the protocols to isolate the compounds are not straightforward and require a special technique. Additionally, the structural determination of the isolated compounds needs to minimize the structure for the elucidation to become easier. Even though resin glycosides have a complicated structural skeleton, several total syntheses of the compounds have been reported in articles published from 2010 to date. This review is an update on the prior studies of the resin glycosides reported in 2010 and 2017. The review includes the classification, isolation techniques, structural determination, biological properties, and total synthesis of the resin glycosides.

Chemistry and biological activity of resin glycosides from Convolvulaceae species

Carbohydrate-based drug discovery has gained more and more attention during the last few decades. Resin glycoside is a kind of novel and complex glycolipids mainly distributed in plants of the family Convolvulaceae. Over the last decade, a number of natural resin glycosides and derivatives have been isolated and identified, and exhibited a broad spectrum of biological activities, such as cytotoxic, multidrug-resistant reversal on both microbial pathogens and mammalian cancer cells, antivirus, anticonvulsant, antidepressant, sedative, vasorelaxant, laxative, and α-glucosidase inhibitory effects, indicating their potential as lead compounds for drug discovery. A systematic review of the literature studies was carried out to summarize the chemistry and biological activity of resin glycosides from Convolvulaceae species, based on various data sources such as PubMed, Web of Science, Scopus, and Google scholar. The keyword "Convolvulaceae" was paired with "resin glycoside," "glycosidic acid," "glycolipid," or "oligosaccharide," and the references published between 2009 and June 2021 were covered. In this article, we comprehensively reviewed the structures of 288 natural resin glycoside and derivatives newly reported in the last decade. Moreover, we summarized the biological activities and mechanisms of action of the resin glycosides with pharmaceutical potential. Taken together, great progress has been made on the chemistry and biological activity of resin glycosides from Convolvulaceae species, however, more exploratory research is still needed, especially on the mechanism of action of the biological activities.

In Vitro Assessment of Antiproliferative Activity and Cytotoxicity Modulation of Capsicum chinense By-Product Extracts

Capsicum chinense J., also known locally as habanero pepper, is a medicinal herb known for its pharmacological properties. Its properties are attributed to the capsaicinoids and polyphenols found in its fruit and polyphenols in its by-products. The anticancer potential of C. chinense by-products remains unexplored. This study aimed to evaluate the antiproliferative activity and modulation of the cytotoxicity of extracts obtained from C. chinense by-products of plants grown on black and red soils of Yucatan, Mexico. Dry by-product extracts were obtained using maceration, a Soxhlet, and supercritical fluid extraction. In vitro antiproliferative activity and cytotoxicity modulation were evaluated by the sulforhodamine B method. The extract of leaves of plants grown on black soil obtained by maceration displayed selective high cytotoxicity against colorectal cancer cells, IC50 HCT–15 = 16.23 ± 2.89 µg mL−1. The leaf and stem extracts of plants grown on red soil obtained by maceration potentiated the vinblastine’s effect against parental breast cancer cells, MCF–7/Sens, with a reversion factor of 362.50-fold. Additionally, the extract of stems from plants grown on black soil obtained by supercritical fluid extraction and all the by-product extracts from plants grown on black soil obtained through maceration increased the effect of vinblastine against MCF–7/Vin+ with a reversion factor from 5.06- to 7.78-fold. These results highlight the anticancer potential of C. chinense by-products.

Mass Defect Filtering-Oriented Identification of Resin Glycosides from Root of Convolvulus scammonia Based on Quadrupole-Orbitrap Mass Spectrometer

This work aimed to develop and evaluate a post-acquisition data processing strategy, referred to as a mass defect filter (MDF), for rapid target the resin glycosides in root of Convolvulus scammonia by setting mass rang and mass defect range from high-resolution MS data. The full-scan mass data were acquired by high-performance liquid chromatography coupled with Q Exactive Plus hybrid quadrupole-orbitrap mass spectrometer that featured high resolution, mass accuracy, and sensitivity. To screen resin glycosides, three parent filter m/z 871, m/z 853, and m/z 869 combined with diagnostic fragment ions (DFIs) approach were applied to remove the interference from complex herbal extract. The targeted components were characterized based on detailed fragment ions. Using this approach, 80 targeted components, including 22 glycosidic acids and 58 resin glycosides were tentatively identified. The present results suggested that the proposed MDF strategy would be adaptable to the analysis of complex system in relevant filed.

Resin Glycosides from the Roots of Operculina macrocarpa (Brazilian Jalap) with Purgative Activity

Analysis of the methanol-soluble resin glycosides from the roots of Operculina macrocarpa was assessed by generating NMR profiles of five glycosidic acids obtained through saponification, acetylation, and recycling HPLC purification. Operculinic acid H (1), two novel hexasaccharides, operculinic acids I (2) and J (3), the known purgic acid A (4), and a quinovopyranoside of (-)-(7 R)-hydroxydecanoic acid, operculinic acid K (5), were isolated. Three intact resin glycosides related to 1, the novel macrocarposidic acids A (6) and B (7), in addition to the previously known macrocarposidic acid C (8), were also purified with isovaleroyl, tigloyl, and exogonoyl [(3 S,9 R)-3,6:6,9-diepoxydecanoyl] groups as esterifying residues. A selective intramolecular lactonization was produced to generate a macrocyclic artifact (17) during acetylation of 1, resembling the distinctive structure of the Convolvulaceous resin glycosides.

Chemistry and Biology of Selected Mexican Medicinal Plants

Herbal medicines are an integral element of alternative medical care in Mexico, and the best testimony to their efficacy and cultural value is their persistence in contemporary Mexican marketplaces where the highest percentages of medicinal and aromatic plants are sold. This chapter summarizes current trends in research on medicinal plants in Mexico, with emphasis on work carried out at the authors' laboratories. The most relevant phytochemical and pharmacological profiles of a selected group of plants used widely for treating major national health problems are described.From this contribution, it is evident that in the last five decades a significant amount of research on medicinal plants has been performed by Mexican scientists. Such efforts have led to the publication of many research papers in noted peer-reviewed journals and technical books. The isolation and structural characterization of hundreds of bioactive secondary metabolites have been accomplished, and most importantly, these studies have tended to support the ethnomedical uses of many different species. A multidisciplinary approach for investigating these plants has led to an increased emphasis on areas such as phytopharmacology, phytotoxicology, quality control, regulation, and conservation issues for these valuable resources. The medicinal plants analyzed so far have shown a very broad chemical diversity of their constituents, which have a high potential for exhibiting novel mechanistic effects biologically. The chapter shows also that there is need to conduct additional clinical studies on herbal drugs, in particular because the longstanding traditional evidence for their safety is not always sufficient to assure their rational use. There is also need to move to "omics" approaches for investigating the holistic effect and the influence of groups of phytochemicals on the whole organism. Mexican scientists may be expected to have bright prospects in this regard, which will imbue medicinal plant research with a new dynamism in the future.

Morning glory resin glycosides as α-glucosidase inhibitors: In vitro and in silico analysis

Twenty-seven individual resin glycosides from the morning glory family (Convolvulaceae) were evaluated for their α-glucosidase inhibitory potential. Four of these compounds displayed an inhibitory activity comparable to acarbose, which was used as a positive control. Molecular modeling studies performed by docking analysis were accomplished to predict that the active compounds and acarbose bind to the α-1,4-glucosidase enzyme catalytic site of MAL12 from the yeast Saccharomyces cerevisiae through stable hydrogen bonds primarily with the amino acid residues HIS279 and GLN322. Docking studies with the human maltase-glucoamylase (MGAM) also identified binding modes for resin glycosides inside the catalytic site in the proximity of TYR1251. These results postulate that resin glycosides may be a source of phytotherapeutic agents with antihyperglycemic properties for the prophylaxis and treatment of non-insulin-dependent type 2 diabetes mellitus.

Amphiphilic glycoconjugates as potential anti-cancer chemotherapeutics

Amphiphilicity is one of the desirable features in the process of drug development which improves the biological as well as the pharmacokinetics profile of bioactive molecule. Carbohydrate moieties present in anti-cancer natural products and synthetic molecules influence the amphiphilicity and hence their bioactivity. This review focuses on natural and synthetic amphiphilic anti-cancer glycoconjugates. Different classes of molecules with varying degree of amphiphilicity are covered with discussions on their structure-activity relationship and mechanism of action.

Resin glycosides from Convolvulaceae plants

Resin glycosides are well known as purgative ingredients, which are characteristic of certain crude drugs such as Mexican Scammony Radix, Orizabae Tuber, and Jalapae Tuber, all of which originate from Convolvulaceae plants. Depending on their solubility in ether, these are roughly classified into two groups—jalapin (soluble) and convolvulin (insoluble). Almost all jalapins hitherto isolated and characterized had common intramolecular macrocyclic ester structures. These are composed of 1 mol of oligoglycoside of hydroxyl fatty acid (glycosidic acid) partially acylated by some organic acids at the sugar moiety, some examples of which are ester-type dimers. On the other hand, convolvulin is regarded as an oligomer of a variety of acylated glycosidic acids. This review describes the isolation and structural elucidation of resin glycosides from some Convolvulaceae plants, including Ipomoea operculata, Pharbitis nil, Quamoclit pennata, Calystegia soldanella, and I. muricata.

Resistance-modifying Activity in Vinblastine-resistant Human Breast Cancer Cells by Oligosaccharides Obtained from Mucilage of Chia Seeds (Salvia hispanica)

The multidrug resistance (MDR) phenotype is considered as a major cause of the failure in cancer chemotherapy. The acquisition of MDR is usually mediated by the overexpression of drug efflux pumps of a P-glycoprotein. The development of compounds that mitigate the MDR phenotype by modulating the activity of these transport proteins is an important yet elusive target. Here, we screened the saponification and enzymatic degradation products from Salvia hispanica seed's mucilage to discover modulating compounds of the acquired resistance to chemotherapeutic in breast cancer cells. Preparative-scale recycling HPLC was used to purify the hydrolysis degradation products. All compounds were tested in eight different cancer cell lines and Vero cells. All compounds were noncytotoxic at the concentration tested against the drug-sensitive and multidrug-resistant cells (IC₅₀  > 29.2 μM). For the all products, a moderate vinblastine-enhancing activity from 4.55-fold to 6.82-fold was observed. That could be significant from a therapeutic perspective. Copyright © 2017 John Wiley & Sons, Ltd.

Diverse tritepenoids from the fruits of Walsura robusta and their reversal of multidrug resistance phenotype in human breast cancer cells

Four 18 (13 → 14)-abeo limonoids, five cedrelone limonoids, and five walsurin limonoids were isolated from the fruits of Walsura robusta together with 21 known compounds. Their structures were determined by extensive studies of their one- and two-dimensional NMR spectra and mass spectroscopy results. Among all the isolated compounds, the absolute configurations of 11-oxo-dihydrocedrelone, walsuronoid B, dysoxylumosin G, and walsunoid H were confirmed by single crystal X-ray diffraction. Selected compounds were evaluated for their reversal of multidrug resistance (MDR) phenotype in human breast cancer cells in vitro. Walsurin A showed significant effect in sensitization of these resistant cancer cells at non-toxic concentration to doxorubicin with the modulation factor of 62.76.