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Resin glycosides are characteristic of plants of the Convolvulaceae family and are well-known purgative ingredients in crude drugs, such as Rhizoma Jalapae, Orizaba Jalapa Tuber, and Pharbitidis Semen, which are used in traditional medicine and derived from plants belonging to this family. Isolated resin glycosides have demonstrated diverse biological activities, including antibacterial, ionophoric, anti-inflammatory, antiviral, and multidrug-resistance-modulating properties, as well as cytotoxicity against cancer cells. These compounds consist of hydroxyl fatty acid oligoglycosides (glycosidic acids), with portions of the saccharide moieties acylated with some organic acids to form the core structure. This study investigated the glycosidic acid components of a crude resin glycoside fraction obtained from a methanolic extract of Ipomoea alba L. seeds (Convolvulaceae). Eleven new glycosidic acid methyl esters and one known methyl ester were isolated from a glycosidic acid fraction treated with trimethylsilyldiazomethane in hexane. Their structures were determined using acidic hydrolysis and electrospray ionization-time of fight mass spectrometry and NMR spectral analyses. These compounds are penta-, tetra-, or triglycosides, with methyl 11S-hydroxytetradecanoate or methyl 11S-hydroxyhexadecanoate as the aglycone. Although D-quinovose and L-rhamnose are common monosaccharide components, the remaining monosaccharides are D-glucose, D-xylose, or D-fucose. The crude resin glycoside fraction showed non-negligible cytotoxicity against HL-60 human promyelocytic leukemia cells., (© 2024. The Author(s) under exclusive licence to The Japanese Society of Pharmacognosy.)

Ipomoea muricata (L.) Jacq. seeds (Convolvulaceae) are used as a traditional laxative and carminative medicine. Muricatins XIV (1), XV (2), XVI (3), and XVII (4), were isolated from I. muricata seeds as four new resin glycosides, along with seven known compounds, three of which were isolated for the first time as natural products; their structures were determined using MS and NMR spectroscopy. Compounds 1-4 are macrolactones (jalapins); the sugar moieties of 1, 2, and 4 are partially acylated with 2S-methylbutyric acid, while that of 3 is esterified with 2S-methylbutyric and 2S-methyl-3S-hydroxybutyric acids. In addition, the antiviral activities of the seven compounds obtained in this study, together with five known compounds obtained in our previous study into resin glycosides from I. muricata seeds, were evaluated against herpes simplex virus type 1 (HSV-1); their cytotoxicities against HL-60 human promyelocytic leukemia cells were also investigated. All examined jalapins exhibited similar or slightly weaker anti-HSV-1 activities than acyclovir, the positive control; however, the glycosidic acid of 4 was inactive, while its methyl ester was weakly active. On the other hand, cytotoxicity testing against HL-60 cells showed similar results to those observed during anti-HSV-1 activity testing, with the exception that one jalapin was less active., (© 2024. The Author(s) under exclusive licence to The Japanese Society of Pharmacognosy.)

Resin glycosides act as laxatives in crude drugs derived from plants of the Convolvulaceae family. These compounds have exhibited antibacterial, ionophoric, anti-inflammatory, antiviral, and multidrug resistance-modulating properties, as well as cytotoxicity against cancer cells. This study investigated the organic acid, hydroxyl fatty acid, monosaccharide, and glycosidic acid components of the crude resin glycoside fraction obtained from the methanol extract of Ipomoea alba L. (Convolvulaceae) seeds, which was subjected to alkaline and acidic hydrolysis. The alkaline hydrolysis yielded acetic, isobutyric, (E)-2-methylbut-2-enoic, and 2S-methyl-3S-hydroxybutyric acids as organic acid components, along with a glycosidic acid fraction. The acidic hydrolysis of the glycosidic acid fraction resulted in the isolation of 11S-hydroxytetradecanoic and 11S-hydroxyhexadecanoic acids as hydroxyl fatty acid components, as well as d-glucose, d-quinovose, d-fucose, d-xylose, and l-rhamnose as monosaccharide components. In addition, 10 new glycosidic acid methyl esters were isolated from the glycosidic acid fraction treated with trimethylsilyldiazomethane-hexane, along with one known glycosidic acid methyl ester. Of these, eight compounds contained new glycans. Four of these compounds were unusual natural glycosides with four glycosidic linkages to one monosaccharide. Their structures were determined using MS and NMR spectral analyses, which provided valuable insights into the unique glycosidic composition of I. alba seeds., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Resin glycosides are commonly found in plants belonging to the Convolvulaceae family. Ipomoea lacunosa L. (Convolvulaceae) is an herbaceous vine native to the United States. The resin glycosides of this plant have not been studied in detail. In this study, the components of the crude resin glycoside fraction extracted from the seeds of I. lacunosa are characterized. Alkaline hydrolysis of the crude resin glycoside fraction obtained from methanolic extract of the seeds yielded three organic acids, namely, 2S-methylbutyric, (E)-2-methylbut-2-enoic, and 2R-methyl-3R-hydroxybutyric acids, and a glycosidic acid fraction. Acidic hydrolysis of the glycosidic acid fraction yielded hydroxyl fatty acid components, including 7S-hydroxydecanoic, 11S-hydroxytetradecanoic, 11S-hydroxyhexadecanoic, 3S,11S-dihydroxytetradecanoic, 3S,11S-dihydroxyhexadecanoic, and 3S,12S-dihydroxyhexadecanoic acids, as well as monosaccharide components, including d-glucose, d-quinovose, d-fucose, and l-rhamnose. Trimethylsilyldiazomethane-hexane treatment of the glycosidic acid fraction further yielded eleven previously undescribed glycosidic acid methyl esters and two known glycosidic acid methyl esters. The structures of the obtained compounds were characterized using various spectral techniques. Four of the undescribed compounds were hexaglycosides, five were heptaglycosides, and two were octaglycosides. The aglycone of these compounds was either methyl 11S-hydroxytetradecanoate, methyl 3S,11S-dihydroxytetradecanoate, or methyl 3S,11S-dihydroxyhexadecanoate. Among the undescribed compounds identified, eight contained novel glycans, and three were rare bisdesmosides with sugar linkages at the C-3 and C-11 positions of methyl 3S,11S-dihydroxytetradecanoate., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Biological effects attributed to resin glycosides, including cytotoxicity against cancer cells and antibacterial, multidrug resistance-modulating, and antiviral activities have been documented. Penta-glycosides composed of calysolic acid A or calyhedic acid A, which are glycosidic acid components of the crude resin glycoside fraction of Calystegia hederacea, have not yet been isolated from this plant. In this study, eight new resin glycosides, termed calyhedins XVI (1)-XXIII (8), were isolated from the rhizomes of C. hederacea. Compounds 1-8 are penta- or hexa-glycosides with macrolactone structures, and their sugar moieties are partially acylated by five organic acids, including 2S-methylbutyric, (E)-2-methylbut-2-enoic, and 2R-methyl-3R-hydroxybutyric acids. Compounds 1-5 are the first identified macrocyclic resin glycosides with five monosaccharides obtained from this plant, and 2 and 4 are the first to be characterized as containing calyhedic acid A as the glycosidic acid component. Compounds 1-8 were of the four following macrolactone types: one with a 22-membered ring (5), another with a 23-membered ring (6-8), the third with a 27-membered ring (1, 3), and the fourth with a 28-membered ring (2, 4). Compounds 2-8 exhibited cytotoxic activity against HL-60 human promyelocytic leukemia cells comparable to that of the positive control, cisplatin., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Two new resin glycosides, muricatins XII ( 1 ) and XIII ( 2 ), were isolated from the crude resin glycoside fraction of the seeds of Ipomoea muricata (L.) Jacq. (Convolvulaceae), along with three known ones, muricatins V ( 3 ), VI ( 4 ), and IX ( 5 ). Compounds 1 and 2 contained new glycosidic acids, muricatic acids E ( 1a ) and F ( 2a ), respectively. The structures of these compounds were determined using data obtained from spectroscopy measurements and chemical evidence. The results suggested that 1 and 2 have macrolactone structures (jalapins). Furthermore, the cytotoxic activity of the crude resin glycoside fraction and 3 - 5 against HL-60 human promyelocytic leukaemia cells was evaluated. All tested samples demonstrated cytotoxic activities.

Calystegia hederacea Wall. (Convolvulaceae) is a perennial herbaceous vine that grows widely in India and East Asia. All parts of this plant are used to treat various disorders such as menoxenia and gonorrhea. Four new resin glycosides, calyhedins XI (1)-XIV (4), were isolated from the rhizomes of C. hederacea. A new glycoside, calyhedin XV (5), was isolated from its leaves and stems. Alkaline hydrolysis of 1 and 2 furnished a new glycosidic acid, calyhedic acid G (1a), from 1 and a new acid, calyhedic acid H (2a), from 2 along with 2S-methylbutyric acid and 2R-methyl-3R-hydroxybutyric (2R,3R-nilic) acid. The structures of 1-5, 1a, and 2a were determined using MS and NMR spectral analyses. Compounds 1a and 2a had the same sugar moiety, β-D-glucopyranosyl-(1 → 6)-O-β-D-glucopyranosyl-(1 → 6)-O-β-D-glucopyranosyl-(1 → 3)-[O-β-D-glucopyranosyl-(1 → 3)-O-α-L-rhamnopyranosyl-(1 → 2)]-O-β-D-glucopyranosyl-(1 → 2)-β-D-fucopyranose, while their aglycones were 11S-dihydroxyhexadecanoic acid and 12S-dihydroxyhexadecanoic acid, respectively. These compounds are the first glycosidic acids, with fucose as the monosaccharide component obtained from the resin glycosides of C. hederacea. Compounds 1-5, comprising either 1a or 2a, were heptaglycosides with macrolactone structures, and their sugar moieties were partially acylated with 5 mol of organic acids comprising 2S-methylbutyric, (E)-2-methylbut-2-enoic, and 2R,3R-nilic acids. Compounds 1 and 5 had 22-membered rings, while 2-4 had 28-membered rings. In addition, 1 and 5 exhibited cytotoxic activity against HL-60 human promyelocytic leukemia cells, comparable to that of the positive control cisplatin., (© 2023. The Author(s) under exclusive licence to The Japanese Society of Pharmacognosy.)

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, 2 S -methylbutyric acid, and 2  R -methyl-3 R -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.

The alkaline hydrolysis of the crude resin glycoside fraction from the leaves and stems of the plant Calystegia japonica Choisy (Convolvulaceae) yielded organic acid and glycosidic acid fractions. The organic acid fraction was esterified with p-bromophenacyl bromide to obtain p-bromophenacyl 2R-methyl-3R-hydroxybutyrate (1) and p-bromophenacyl (E)-2-methylbut-2-enoate (2). By treating the glycosidic acid fraction with trimethylsilyldiazomethane-hexane, seven new methyl esters of glycosidic acids, namely calyjaponic acid A methyl ester (3) calyjaponic acid B methyl ester (5), calyjaponic acid C methyl ester (6), calyjaponic acid D methyl ester (7), calyjaponic acid E methyl ester (8), calyjaponic acid F methyl ester (9), and calyjaponic acid G methyl ester (10), were isolated along with one known ester (4). Their structures were characterized based on spectroscopic and chemical analyses. Compounds 3-8 had the same sugar moiety, α-L-rhamnopyranosyl-(1 → 2)-O-β-D-glucopyranosyl-(1 → 2)-[O-α-L-rhamnopyranosyl-(1 → 6)]-O-β-D-glucopyranose, and the aglycones of 3-8 were methyl 3S,11S-dihydroxyhexadecanoate, methyl 3S,12S-dihydroxyhexadecanoate, methyl 11S-hydroxyhexadecanoate, methyl 11S-hydroxypentadecanoate, methyl 3S,11S-dihydroxypentadecanoate, and methyl 3S,12S-dihydroxypentadecanoate, respectively. Compounds 9 and 10 were derivatives of 3 and 4, respectively, in which the C-6 of the second glucosyl residue was methylated. Compounds 6-8 contained methyl esters of unusual odd-carbon fatty acids as aglycones. The cytotoxicity of the crude resin glycoside fraction and 3 against HL-60 human promyelocytic leukemia cells was evaluated further; both were either weakly active or inactive compared to the positive control, cisplatin., (© 2022. The Author(s) under exclusive licence to The Japanese Society of Pharmacognosy.)

Scope and Aim: Sweet potato is widely consumed as a healthy and nutritive vegetable containing bioactive constituents for health promotion. This study investigated the beneficial impact of white-fleshed sweet potato extract (SPE) on high fat diet (HFD)-induced obese mice., Methods and Results: First, SPE, in which resin glycoside was found as the dominant constituent, was suggested as a potential anti-obesity agent, because 20-70% pancreatic lipase (PL) inhibition was measured with SPE by in vitro turbidity assay and pNPP assay. Hence, next, the effect of SPE on obese mice was detected by oral administration of HFD supplemented with 6% SPE on C57BL/6J mice for 9 weeks. Surprisingly, being the opposite of what was typically observed from a lipase inhibitor such as orlistat, the fecal fat content in SPE-fed obese mice was decreased ( p < 0.01). Meanwhile, 6% SPE supplement indeed significantly ameliorated HFD-induced obesity in mice, including body weight gain, fat accumulation, adipocyte enlargement, insulin resistance, and hepatic steatosis ( p < 0.05). The improved liver steatosis was found associated with a down-regulating action of SPE on nuclear factor kappa B activation in HFD-fed mice. The anti-obesity influence of SPE was also confirmed on the HepG2 cell model for non-alcoholic fatty liver disease (NAFLD)., Conclusion: These results indicate that SPE, as a dietary supplement, has the great potential for weight control and treating hepatic steatosis, possibly through a different action mechanism from that of orlistat., Competing Interests: Author XY was employed by Suzhou Kosmode Biotechnology Company. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer FZ declared a shared affiliation with the author YY to the handling editor at the time of review., (Copyright © 2022 Liu, Wu, Chen, Pan, Yin, You, Song, Li and Huang.)

Purpose: The medicinal plant Ipomoea aquatica belonging to convulvulaceae family is an effective natural herb for treatment of various ailments and possesses effective anticancer activity. The aim of the work is to characterize a secondary metabolite merromoside (a resin glycoside) for anti-breast cancer activity through down regulation of ROS species., Methods: The Extract of the whole plant has been prepared by maceration method using 50%v/v ethanol in distilled water to get a hydroalcoholic extract. The phytochemical evaluation reveals that the active secondary metabolite was isolated by using column chromatographic technique. The isolated compound was evaluated for its anticancer properties through invitro method such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay on Michigan Cancer Foundation-7 Cell lines. The purity and structural characterization were done by high-performance thin layer chromatography, Fourier Transform Infrared Spectroscopy, Proton and13C Nuclear Magnetic Resonance spectroscopy and Liquid Chromatography-Mass Spectrometry., Results: The isolated compound (W04) from the derived extract showed Rf value of 0.79 that showed IC50 of 182.8μg/ml. The chemical structure of W04 has been confirmed as [4,5-dihydroxy-6-[5-hydroxy-2-methyl-4-(2-methylpropanoyloxy)-6-[(24,25,26-trihydroxy-5,23-dimethyl-9-oxo-19-pentyl-2,4,8,20,22-pentaoxatricyclo[19.2.2.13,7]hexacosan-6-yl)oxy]oxan-3-yl]oxy-2-methyloxan-3-yl] 2-methyl propanoate with the molecular weight of 979.15268. The isolated compound merromoside from hydroalcoholic extract of Ipomoea aquatica has been evaluated for anti-breast cancer properties. The down regulation of ROS species will prevent reverse signalling and angiogenesis. This indicates that merromoside will overcome MDR in breast cancer especially DOX-resistant.

Background: Pharbitidis Semen (the seeds of Pharbitis nil), traditionally used as a purgative in Japan, China and Korea, contains a resin glycoside fraction named pharbitin, which is known as a purgative ingredient. Due to the complex nature of pharbitin, little is known about either the action on intestinal tension caused by resin glycoside itself or by its components., Methods: In this study, we investigated the effects of pharbitin, the glycosidic acid fraction (pharbitic acid) and the aglycone fraction (phar-genin) generated from pharbitin on peristalsis of colon and ileum isolated from mice with the Magnus method., Results: We demonstrated that pharbitin (3-30 μg/mL) concentration-dependently increased tonus of mice colon via acetylcholine receptors, its components phar-genin (1.27-12.7 μg/mL) and pharbitic acid (10-1000 μg/mL) also had the increment on colon tonus. On the other hand, ileum tension decreased in the presence of pharbitin., Conclusions: The effects of resin glycoside of Pharbitidis Semen on colon tonus are different with those on ileum tonus isolated from mice. In the next step it is necessary to investigate details of its pharmacological mechanism., (© 2022. The Author(s).)

Two new glycosidic acids, calyhedic acids E ( 1a ) and F ( 2a ), were isolated from the glycosidic acid fraction afforded by alkaline hydrolysis of the crude resin glycoside fraction obtained from whole plants of Calystegia hederacea Wall. Compounds 1a and 2a were characterised as 11 S -hydroxyhexadecanoic acid 11- O -β-D-glucopyranosyl-(1→6)- O -β-D-glucopyranosyl-(1→6)- O -β-D-glucopyranosyl-(1→3)-[ O -α-L-rhamnopyranosyl-(1→2)]- O -β-D-glucopyranosyl-(1→2)-β-D-quinovopyranoside and an isomer of 1a , in which the 11 S -hydroxyhexadecanoyl residue of 1a was replaced by a 12 S -hydroxyhexadecanoyl residue, respectively, on the basis of spectroscopic data.

Two new glycosidic acids, evolvulic acids B and C ( 1 and 2 ), along with a known one, evolvulic acid A ( 3 ), were isolated from the glycosidic acid fraction afforded by alkaline hydrolysis of crude resin glycosides from Evolvulus alsinoides whole plants. Their structures were characterized by the spectroscopic data and chemical evidences. Compounds 1 and 2 are both defined as tetrasaccharides, composed of D-fucose, D-glucose, L-rhamnose or D-galactose units. Their aglycones are identified to be a distinctive 3 S ,11 R ,14 R -trihydroxyhexadecanoic acid, which is only discovered from E. alsinoides up to now. The cytotoxic and anti-migration activities of compounds 1-3 were also tested.

Six previously undescribed resin glycosides, calyhedins I-VI, were isolated from the rhizomes of Calystegia hederacea Wall., which are the first genuine resin glycosides isolated from C. hederacea. The structures of calyhedins I-VI were determined based on spectroscopic data and chemical evidence. All the compounds have macrolactone structures (jalapins), and their sugar moieties were partially acylated by five organic acids. Calyhedins I, II-V, and VI have 27-, 28-, and 23-membered rings, respectively, and calyhedins IV-VI are the first jalapins with a sugar chain consisting of seven monosaccharides. Additionally, the cytotoxic activity of calyhedins II and III toward HL-60 human promyelocytic leukemia cells was evaluated. Both compounds demonstrated almost the same activity as the positive control, cisplatin., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Alkaline hydrolysis of crude resin glycoside fraction of the seeds of Ipomoea muricata (L.) Jacq. (Convolvulaceae) yielded a new glycosidic acid, muricatic acid D; three known glycosidic acids, namely, muricatic acids A, B, and C; and three known organic acids, namely, isobutyric, 2S-methylbutyric, and 2S-methyl-3S-hydroxybutyric acid. Two new genuine resin glycosides with macrolactone structures (jalapins), muricatins X and XI, were also isolated from the fraction. Their structures were determined using spectroscopic data and chemical evidence.

Resin glycosides are well known as the purgative ingredients, which are characteristic of convolvulaceous plants. Calystegia hederacea Wall. is a perennial herbaceous vine that is widespread throughout India and East Asia. All parts of this plant are used for the treatment of menoxenia, gonorrhea, etc. Alkaline hydrolysis of the crude resin glycoside fraction of the whole plants of C. hederacea yielded four new glycosidic acids, calyhedic acids A, B, C, and D, along with two known glycosidic acids, calysolic acids A and C, and three known organic acids, 2S-methylbutyric, tiglic, and 2R,3R-nilic acids. Their structures were characterized on the basis of spectroscopic data and chemical evidence. Calyhedic acids A, B, and D were penta-, hexa-, and hepta-glycosides of 12S-hydroxyhexadecanoic acid, respectively, and cayhedic acid C was an isomer of calyhedic acid D, in which the 12S-hydroxyhexadecanoyl residue of calyhedic acid D was replaced by a 11S-hydroxyhexadecanoyl residue. Additionally, cytotoxic activity toward HL-60 human promyelocytic leukemia cells of the crude resin glycoside fraction, the glycosidic acid fraction, calyhedic acid A, and calysolic acid A from C. hederacea was evaluated. Furthermore, to clarify the structure-activity relationship of resin glycosides, the activities of six genuine resin glycosides with calysolic acid A or calysolic acid C as the glycosidic acid, which were isolated from C. soldanella, were examined. Among them, the crude resin glycoside fraction and five genuine resin glycosides with macrolactone structures demonstrated clear cytotoxic activities, while the glycosidic acid fraction, calyhedric acid A, calysolic acid A, and a genuine non-macrolactone-type resin glycoside were either inactive or exhibited weaker activity than the tested macrolactone-type resin glycosides.

Pharbitidis Semen has worldwide recognition in traditional medicine for the treatment of several illnesses apart from its purgative properties, and it is also reported to show anticancer effect. However, limited pharmacological studies are available on the extract or resin glycosides fraction of Pharbitidis Semen. The purpose of this study was to determine the mechanism of the colon cancer cell cytotoxic effect of a purified resin glycoside fraction from Pharbitidis Semen (RFP). Our results showed that the RFP-induced cell death was mediated by the caspase-independent and autophagy-protective paraptosis, a type of cell death that is characterized by the accumulation of cytoplasmic vacuoles and mitochondria swelling. RFP significantly stimulated endoplasmic reticulum stress, inhibited proteasome-dependent degradation, and activated the MAPK signaling pathway in human colon cancer cell lines. Furthermore, we found that RFP activated chloride intracellular channel-1 (CLIC1) and increased the intracellular Cl - concentration. Blockage of CLIC1 by DIDS (disodium 4,4'-diisothiocyanato-2,2'-stilbenedisulfonate hydrate) attenuated cell death, cytoplasmic vacuolization, and endoplasmic reticulum stress, suggesting that CLIC1 acts as a critical early signal in RFP-induced paraptosis. In conclusion, results obtained indicated that the cytotoxic effect of RFP in colon cancer cells was the outcome of paraptosis mediated by activation of CLIC1.

Seven new resin glycosides, multifidins III (1)-IX (7), were isolated from the seeds of Quamoclit × multifida (syn. Q. sloteri House) (Convolvulaceae), along with five known glycosides, quamoclinic acid B methyl ester (8), operculin XIII (9), quamoclin I (10), QM-10 (11), and QM-12 (12). Their structures were determined on the basis of spectroscopic data and chemical evidence. These compounds were of two different types, i.e., those with macrolactone structures and those with non-macrolactone structures. Additionally, cytotoxic activity towards HL-60 human leukemia cells of 1, 2, 5, 8, 9, 11, and 12 was evaluated. Among them, macrolactone-type resin glycosides (jalapins), 1, 2, and 9, specifically demonstrated clear cytotoxic activity with IC 50 values of 3.46, 14.7, and 10.9 μM, respectively.

Four new resin glycosides having macrolactone structures (jalapins), murasakimasarins I-IV, were isolated from the tubers of Ipomoea batatas (L.) Lam. ('Murasakimasari', Convolvulaceae), along with three known glycosides. Their structures were determined on the basis of spectroscopic data as well as chemical evidence. Murasakimasarin III is the first representative of a resin glycoside with 10-methylundecanoic acid as the component organic acid.

In the present study, three compounds were isolated from Argyreia acuta, among them, compounds 1 and 2 were new and Compounds 1 and 3 were isomers. They were separated by several types of columns, such as normal phase, RP, size exclusion and preparative HPLC, and their structures were elucidated by several spectroscopic methods, such as 1D- and 2D-NMR and HR-TOF-MS., (Copyright © 2018 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.)

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., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A new resin glycoside, named calysolin XVIII (1), was isolated from the leaves, stems and roots of Calystegia soldanella Roem. et Schult. (Convolvulaceae). The structure of 1 was defined as 11S-jalapinolic acid 11-O-β-d-glucopyranosyl-(1 → 3)-O-(2-O-2S-methylbutyryl,4-O-3-hydroxy-2-methylenebutyryl)-α-l-rhamnopyranosyl-(1 → 2)-[O-β-d-glucopyranosyl-(1 → 6)-O-(34-di-O-2S-methylbutyryl)-β-d-glucopyranosyl-(1 → 3)]-O-β-d-glucopyranosyl-(1 → 2)-β-d-quinovopyranoside, intramolecular 1,2″'″'-ester on the basis of spectroscopic data. Compound 1 is the first known resin glycoside to feature 3-hydroxy-2-methylenebutyric acid as a component organic acid. In addition, 1 demonstrated an antiviral activity against herpes simplex virus type 1, with an IC 50 value 2.3 μM.

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.

Six new partially acylated resin glycosides were isolated from convolvulin of Ipomoea purga, Ipomoea stans, and Ipomoea murucoides (Convolvulaceae). The structures of compounds 1-6 were elucidated by a combination of NMR spectroscopy and mass spectrometry. The structure of jalapinoside B (1) consists of a hexasaccharide core bonded to an 11-hydroxytetradecanoic (convolvulinic) acid forming a macrolactone acylated by a 2-methylbutanoyl, a 3-hydroxy-2-methylbutanoyl, and a quamoclinic acid B units. Purginoic acid A (2) contains a hexasaccharide core bonded to a convolvulinic acid acylated by a 3-hydroxy-2-methylbutanoyl unit. Stansin A (4) is an ester-type heterodimer, and consists of two stansoic acid A (3) units, acylated by 2-methylbutanoic and 3-hydroxy-2-methylbutanoic acids. The site of lactonization was located at C-3 of Rhamnose, and the position for the ester linkage of the monomeric unit B on the macrolactone unit A was established as C-4 of the terminal rhamnose. Compounds 5 and 6 are glycosidic acids. Murucinic acid II (5) is composed of a pentasaccharide core bonded to an 11-hydroxyhexadecanoic (jalapinolic) acid, acylated by an acetyl unit. Stansinic acid I (6) is a tetrasaccharide core bonded to a jalapinolic acid, acylated by 2-methylbutanoyl and 3-hydroxy-2-methylbutanoyl units. Preliminary testing showed the cytotoxicity of compounds 1-6 toward OVCAR and UISO-SQC-1 cancer cell lines. In addition, compound 1 showed an antiproliferative activity on glioma C6 and RG2 tumor cell lines. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

In the present study, two new compounds from Ipomoea cairica were identified and demonstrated to have α-glucosidase inhibitory activity. They were isolated by column chromatography on silica gel and sephadex LH-20 and finally purified by prep-HPLC, with their structures being elucidated by spectroscopic methods, such as 1D- and 2D-NMR and HR-TOF-MS, and chemical methods. Compounds 1 and 2, named cairicoside A and cairicoside B, were evaluated for α-glucosidase inhibitory activity by the MTT method, with the IC50 values being 25.3 ± 1.6 and 28.5 ± 3.3 μmol·L(-1), respectively., (Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.)

Two new compounds of acutacosides 1 and 2, pentasaccharide resin glycosides were isolated from the aerial parts of Argyreia acuta. The core of the two compounds was operculinic acid A, and they were esterfied at the same position, just one substituent group was linked at C-2 of Rha. The absolute configuration of the aglycone in the two compounds was established by Mosher's method, which was (11S)-hydroxyhexadecanoic acid (jalapinolic acid). Their structures were established by a combination of spectroscopic and chemical methods.

We present in this paper the efficient synthesis of three macrocyclic lactone units which are core structures of natural resin glycosides by the use of a Keck macrolactonization approach.

Stansin 6 a tetrasaccharide resin glycoside isolated from the root of Ipomoea stans was evaluated as anticonvulsant and neuroprotective in kainic acid-induced seizures of rats. Intraperitoneal injection of kainic acid (10 mg/kg) induced typical behavioral seizures such as wet dog shakes and limbic seizures, and histopathological changes in the hippocampus (degeneration and loss of pyramidal cells in CA1 to CA4 areas). Stansin 6 (10-80 mg/kg) had no effect on the behavior of rats and did not induce hippocampal damage. Pretreatment with stansin 6 inhibited convulsions in rats from kainic acid-induced seizures, reduced the degeneration pattern in the CA3 region, decreased astrocytic reactivity, and reduced the expression of IL-1β and TNF-α induced by kainic acid. These results suggest that stansin 6 possesses neuroprotective and anticonvulsant activities., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Six partially acylated pentasaccharide resin glycosides, cairicosides A-F, were isolated from the aerial parts of Ipomoea cairica. These compounds were characterized as a group of macrolactones of simonic acid A, partially acylated with different organic acids. The lactonization site of 11S-hydroxyhexadecanoic acid (jalapinolic acid) was bound to the second saccharide moiety at C-3 in cairicosides A-E, while at C-2 in cairicoside F. Structures were established by spectroscopic and chemical methods. Compounds cairicosides A-E exhibited moderate cytotoxicity against a small panel of human tumor cell lines with IC50 values in the range of 4.28-14.31μM., (Copyright © 2013 Elsevier Ltd. All rights reserved.)