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Resin glycosides, characteristic of plants of the Convolvulaceae family, are well-known purgative constituents found in traditional medicinal crude drugs, such as Rhizoma Jalapae, Rhizoma Jalapae Braziliensis, Orizaba Jalapa Tuber, and Pharbitidis Semen. The isolated compounds exhibited a wide range of biological activities, including antibacterial, ionophoric, anti-inflammatory, antiviral, and multidrug-resistance-modulating properties, as well as cytotoxicity against cancer cells. Ipomoea lacunosa L. (Convolvulaceae) is an herbaceous vine native to the United States. Four new acylated glycosidic acid methyl esters (1-4) and one new glycosidic acid (5) were isolated from the methanol extract of the plant seed. The structures of 1-5 were elucidated using spectroscopic data in conjunction with our previous studies on the components of the crude resin glycoside fraction from I. lacunosa seeds. Compounds 1 and 2 were identified as heptaglycosides, 3 as an octaglycoside, and 4 as a nonaglycoside, all sharing methyl 3S,11S-dihydroxytetradecanoate as a common aglycone. The saccharide moieties were partially acylated by glycosidic acid, 7S-hydroxydecanoic acid 7-O-β-D-quinovopyranoside, and organic acids, including (E)-2-methylbut-2-enoic, 2S-methylbutyric, and 2R-methyl-3R-hydroxybutyric acids. Compound 5 was identified as a triglycoside with a new aglycone, 4,11-dihydroxyhexadecanoic acid, which is the first glycosidic acid with a hydroxyl group at C-4 of the aglycone moiety., Competing Interests: Declarations. Conflict of interest: The authors declare no competing financial interest., (© 2025. The Author(s).)

Ipomoea alba L. (Convolvulaceae) is an annual vine native to tropical America that is cultivated primarily for ornamental purposes. Its seeds are used in traditional medicine as a laxative, and young shoots are consumed as food. In this study, ten new resin glycosides, ipoalbins I (1)-X (10), were isolated from I. alba seeds. The structures of 1-10 were determined based on spectroscopic data. All compounds had intramolecular cyclic ester structures (jalapins). The sugar moieties in 1-10 were partially acylated by organic acids, including isobutyric, (E)-2-methylbut-2-enoic, and 2S-methyl-3S-hydroxybutyric acids. Notably, one of these compounds has a rare jalapin structure characterized by an ester linkage between the carboxyl group of the aglycone moiety and the hydroxyl group of an organic acid attached to the sugar moiety. In contrast, other compounds exhibited typical macrolactone structures. Furthermore, the cytotoxic activity of 1-10 against HL-60 human promyelocytic leukemia cells and their antiviral activity against herpes simplex virus type 1 (HSV-1) were evaluated. All tested compounds, except 3, were comparable to or slightly less cytotoxic than cisplatin, the positive control. In addition, all the compounds showed anti-HSV-1 activity; notably, 5 showed an EC 50 value lower than that of acyclovir, the positive control. However, the selectivity indices of these compounds were lower than that of acyclovir., Competing Interests: Declarations. Conflict of interest: The authors declare no competing financial interest., (© 2024. The Author(s) under exclusive licence to The Japanese Society of Pharmacognosy.)

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.)

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.)

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.)

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.

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.

Because inhibitors of advanced glycation end-products (AGEs), for example pyridoxamine, significantly inhibit the development of retinopathy and neuropathy in rats with streptozotocin-induced diabetes, treatment with AGE inhibitors is believed to be a potential strategy for the prevention of lifestyle-related diseases such as diabetic complications. In the present study, the MeOH extract of Epimedii Herba (EH; aerial parts of Epimedium spp.) was found to inhibit the formation of N (ε) -(carboxymethyl)lysine (CML) and N (ω) -(carboxymethyl)arginine (CMA) during incubation of collagen-derived gelatin with ribose. Furthermore, compounds with inhibitory effects against CML and CMA formation were isolated from EH. Two new prenylflavonoids (compounds 1 and 2) and two known compounds (3 and 4) were found to significantly inhibit the formation of both CML and CMA; compound 4 (epimedokoreanin B) had the strongest inhibitory effect of the isolated compounds. These data suggest that epimedokoreanin B could prevent clinical complications of diabetes by inhibiting AGEs.

Two new glycosidic acids, multifidinic acids F and G, were isolated from the glycosidic acid fraction afforded by alkaline hydrolysis of the ether-insoluble resin glycoside (convolvulin) fraction from the seeds of Quamoclit × multifida (syn. Q. sloteri House, Convolvulaceae), a hybrid between Q. pennata and Q. coccinea. The two compounds are the third and fourth examples of bisdesmosides of glycosidic acids having sugar linkages at C-3 of 3,11-dihydroxytetradecanoic acid (ipurolic acid) as well as at C-11.

A new diterpenoid was isolated from the leaves of Clerodendron trichotomumThunb. (Verbenaceae) along with one each of a known diterpenoid, phenylethanoid glycoside, and sterol and two known flavonoids. Their chemical structures were characterized on the basis of spectroscopic data and X-ray analysis. In addition, their antioxidant activities were evaluated using four different analyses.

Alkaline hydrolysis of the ether-insoluble resin glycoside (convolvulin) fraction of the seeds of Quamoclit × multifida (syn. Q. sloteri House, Convolvulaceae), a hybrid between Q. pennat and Q. coccinea, gave three new glycosidic acids (maltifidinic acids C, D, and E) along with three known glycosidic acids (quamoclinic acids B, C, and D) and four organic acids (2S-methylbutyric, tiglic, 2R,3R-nilic, and 7S-hydroxydecanoic acids). The structures of the new glycosidic acids were characterized on the basis of spectroscopic data as well as chemical evidence.

We investigated the constituents of Veronicastrum villosulum (Miquel) Yamazaki (Scrophulariaceae), an endangered species belonging to the IA group. From the aerial parts of this plant cultivated at the botanical garden of Sojo University, we isolated two new cucurbitacine-type glycosides, 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 3)]-beta-D-glucopyranosides of 3beta,25-dihydroxycucurbit-5,23(E)-diene-7-one-25-methyl ether and 3beta,23-dihydroxycucurbit-5,24-diene-7-one-23-methyl ether.

Three new aromatic glycosides were isolated from the ripe fruit of cherry tomato [Lycopersicon esculentum var. cerasiforme (Dunal) Alef. (Solanaceae)] along with six known aromatic glycosides and one known steroidal alkaloid glycoside. Their chemical structures were determined on the basis of spectroscopic data as well as chemical evidence.

A new abietane-type diterpenoid and a new oleanane-type triterpenoid glucosyl ester were isolated from the leaves of Callicarpa japonica Thunb. var. luxurians Rehd. (Verbenaceae) along with 11 known compounds, comprising seven triterpenoids, two sterols, a flavonoid, and an aliphatic glycoside. Their chemical structures were determined on the basis of spectroscopic data.