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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.

Biotransformation of betulonic acid (

Two new glycosidic acids, evolvulic acids B and C (

Evolvulins I and II (

The microbial transformation of 20(R)-panaxadiol (PD) by the fungus Absidia coerulea AS 3.3382 afforded three new and three known metabolites. The structures of the metabolites were characterized as 3-oxo-20(R)-panaxadiol (1), 3-oxo-7β- hydroxyl-20(R)-panaxadiol (2), 3-oxo-22β-hydroxyl-20(R)-panaxadiol (3), 3-oxo- 7β,22β-dihydroxyl-20(R)-panaxadiol (4), 3-oxo-7β,24β-dihydroxyl-20(R)-panaxadiol (5), and 3-oxo-7β,24α-dihydroxyl-20(R)-panaxadiol (6). Among them, 2-4 were new compounds. In addition, compounds 3 and 4 exhibited significant anti-hepatic fibrosis activity.

Novel farnesylthiosalicylic acid (FTA) derivatives 5a – m with different substituted 1,3,4-thiadiazoles were synthesized. Compounds 5b , 5c , 5e and 5f displayed anti-tumor activities superior to FTA in most cancer cells tested. Furthermore, 5e induced tumor cell apoptosis, which was accompanied by lower Bcl-2 expression, but with higher Bax and caspase 3 expression activities in cancer cells.

The biotransformation of arenobufagin (1) and cinobufotalin (2), isolated from the natural medicine Chan Su, by Alternaria alternata AS 3.4578 was carried out. Incubation of 1 and 2 afforded six metabolites: 3-oxo-arenobufagin (1a), ψ-bufarenogin (1b), 3-oxo-ψ-bufarenogin (1c), 3-oxo-Δ4-derivative of cinobufotalin (2a), 3-oxo-cinobufotalin (2b) and 12β-hydroxycinobufotalin (2c). Among them, metabolites 1a, 1c and 2c are new compounds and their structures were characterized on the basis of their spectroscopic data (NMR, MS and IR). Compounds 1, 2, 1b, 2a and 2b were evaluated for their cytotoxicity against HepG2 and MCF-7 human cancer cells, and all of them showed significant inhibitory activities.

The phytochemical investigation of extracts from the roots of Sophora tonkinensis yielded three new isoprenylated flavanones, the tonkinochromanes F (2), G (3), and H (5), along with four known compounds. Structural elucidation of the compounds were established on the basis of spectral data, particularly by the use of 1D NMR and several 2D shift-correlated NMR pulse sequences (1H1H COSY, HSQC, HMBC, and ROESY). Copyright © 2008 John Wiley & Sons, Ltd.

Two new lignans named spicatolignan A (1) and spicatolignan B (2) have been isolated from the whole herbs of Mentha spicata L.

High performance liquid chromatography coupled with photodiode array detection (HPLC–DAD) was employed for the determination of 14 major constituents in traditional Chinese herbal formula ‘Luan-Pao-Prescription’. Two different chromatographic determinations for the 14 constituents were carried out to control the quality of this herbal formula. The sample was extracted under ultrasonic extraction with 75% methanol at the frequency of 42 kHz for 45 min at room temperature. The chromatographic separation was performed on a Zorbax SB-C18. The mobile phase was linear gradient elution of water with 0.5% (v/v) acetic acid (A) and acetonitrile (B) column with linear gradient elution procedure. The flow rate was set at 1.0 mL min−1 and the column temperature was kept at 30 °C. The calibration curve for the determination of all the analytes showed good linearity over the investigated ranges (R 2 > 0.999). The intra- and inter-day assay precision (RSD) of 14 analytes were in the range of 0.2–3.9% and the recoveries were between 92.4 and 104.4%. The validated method was successfully applied to the determination of 14 major constituents in LPP.

The polysaccharides from pumpkin fruit (PP) were obtained and purified by hot-water extraction, anion-exchange chromatography, and gel column chromatography. The physicochemical properties of PP were determined by gel filtration chromatography, gas chromatography, fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. Results indicated that the molecular weight of PP was about 23 kDa and PP was composed of D-Arabinose, D-Mannose, D-Glucose, and D-Galactose with a molar ratio of 1 : 7.79 : 70.32 : 7.05. FTIR and NMR spectra indicated that PP was the polysaccharide containing pyranose ring. Additionally, PP protected islets cells from streptozotocin (STZ) injury in vitro via increasing the levels of super-oxide dismutase (SOD) and malondialdehyde (MDA) and reducing the production of NO. The experiment of reverse transcriptase-polymerase chain reaction further proved that PP inhibited apoptosis via modulating the expression of Bax/Bcl-2 in STZ-damaged islet cells. In conclusion, PP could be explored as a novel agent for the treatment of diabetes mellitus.

A simple, sensitive and specific high-performance liquid chromatography-UV (HPLC-UV) method has been developed to simultaneously quantify the eight major bioactive phenolic compounds in Chinese propolis, namely caffeic acid, isoferulic acid, 3,4-dimethoxycinnamic acid, pinobanksin 5-methyl ether, pinocembrin, benzyl caffeate, chrysin and galangin. This HPLC assay was performed on an Agilent Zorbax Extend-C18 (250 x 4.6 mm, 5 microm) column with a gradient of methanol and 0.2% aqueous acetic acid (v/v) in 50 min, at a flow rate of 1.0 mL/min, and detected at 290 nm. All calibration curves showed good linearity (r20.999) within the test ranges. The intra- and inter-day assay precision (RSD) of eight phenolic compounds were in the range of 0.07-4.92%. The recoveries were between 98.3% and 104.8%. This assay was applied to the evaluation of nineteen samples from different origins in China. The results indicated that the developed assay could be readily utilized for the quality control of propolis.

To study the chemical constituents of Mentha spicata.The chemical constituents were isolated by silica gel column chromatography, and identified by physical and chemical characters and spectroscopic analysis.Compounds I - V were obtained and their structures were elucidated as protocatechuic aldehyde (I), protocatechuic acid (II), chrysoeriol (III), 5, 6-dihydroxy-7, 8, 3', 4'-tetramethoxyflavone (IV), nodifloretin (V).Compound I and II were first isolated from the genus Mentha. Compound Ill, IV and V were isolated from M. spicata for the first time.