Citrullus colocynthis (L.) Schrad.: A Promising Pharmaceutical Resource for Multiple Diseases.

Citrullus colocynthis (L.) Schrad. (Cucurbitaceae) is widely distributed in the desert areas of the world. The fruit bodies of C. colocynthis are recognized for their wide range of nutraceutical potential, as well as medicinal and pharmaceutical uses. The plant has been reported for various uses, such as asthma, bronchitis, cancer, colic, common cold, cough, diabetes, dysentery, and jaundice. The fruit has been extensively studied for its biological activities, which include insecticide, antitumor, and antidiabetic effects. Numerous bioactive compounds have been reported in its fruit bodies, such as essential oils, fatty acids, glycosides, alkaloids, and flavonoids. Of these, flavonoids or caffeic acid derivatives are the constituents associated with the inhibition of fungal or bacterial growth, whereas eudesmane sesquiterpenes or sesquiterpene lactones are most active against insects, mites, and nematodes. In this review, the scientific evidence for the biological activity of C. colocynthis against insecticide, cytotoxic, and antidiabetic effects is summarized.

Cardiac Protection of a Novel Lupane-Type Triterpenoid from Injuries Induced by Hypoxia-Reperfusion.

Myocardial ischemia-reperfusion injury (MIRI) leads to cardiac remodeling and heart failure associated with acute myocardial infarction, which is one of the leading causes of death worldwide. Betulinic acid (BA), a widely distributed lupane-type triterpenoid, has been reported to possess antioxidative activity and inhibit apoptosis in MIRI. Due to the low bioavailability and water insolubility of BA, a previous study found a series of BA-derivative compounds by microbial transformation. In this study, we observe whether there are anti-MIRI effects of BTA07, a BA derivative, on cardiac injuries induced by hypoxia/reoxygenation (H/R) in adult rat cardiomyocytes in vitro and in Langendorff-perfused hearts ex vivo, and further explore its mechanism of cardioprotection to find more efficient BA derivatives. The hemodynamic parameters of isolated hearts were monitored and recorded by a Lab Chart system. The markers of oxidative stress and apoptosis in isolated hearts and adult rat cardiomyocytes (ARCMs) were evaluated. The expression levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), protein kinase B (Akt) and phospho-Akt (pAkt, Ser473) induced by H/R were detected via Western blot. The Langendorff experiments showed that BTA07 improves hemodynamic parameters, reduces myocardium damage and infarct size, inhibits levels of myocardial tissue enzymes lactate dehydrogenase (LDH) and creatine kinase (CK) in the coronary outflow and reduces oxidative stress and the activation of caspase-3 in the myocardium. In vitro, BTA07 reduced cell death and caspase-3 activation and inhibited reactive oxygen species (ROS) generation. Furthermore, the protective effects of BTA07 were attenuated by inhibition of the PI3K/Akt signaling pathway with LY294002 in ARCMs. BTA07 protects ARCMs and isolated hearts from hypoxia-reperfusion partly by inhibiting oxidative stress and cardiomyocyte apoptosis.

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.

Evolvulins I and II, Resin Glycosides with a Trihydroxy Aglycone Unit from Evolvulus alsinoides.

Evolvulins I and II (1 and 2), representing a new class of resin glycosides with an unprecedented trihydroxy aglycone unit, 3S,11R,14R-trihydroxyhexadecanoic acid (4), were isolated from the whole plants of Evolvulus alsinoides. Their structures were thoroughly characterized by extensive spectroscopic analyses as well as chemical evidence. Compound 1 exhibited the most potent cytotoxic activity against MCF-7 cells, with an IC50 value of 3.12 µM.

Biotransformation of betulin by Mucor subtilissimus to discover anti-inflammatory derivatives.

Biotransformation of lupane-type triterpenoid betulin was carried out with Mucor subtilissimus CGMCC 3.2456. Yielded nine previously undescribed hydroxylated compounds. M. subtilissimus biotransformation provided C-7, C-11, C-15 and C-24 hydroxylated compounds along with C-7 oxidized and C-28 acetylated derivatives. The structures of the metabolites were established based on extensive NMR and HR-ESI-MS data analyses. Furthermore, we found that most of the metabolites exhibited pronounced inhibitory activities on lipopolysaccharides-induced NO production in RAW264.7 cells.

Biotransformation of 20(R)-panaxatriol by the fungus Aspergillus flavus Link AS 3.3950.

Microbial transformation of 20(R)-panaxatriol by the fungus Aspergillus flavus Link AS 3.3950 was performed. Four new (1-4), along with two previously reported metabolites (5 and 6), were obtained. Their chemical structures were elucidated on the basis of extensive spectroscopic analyses. Furthermore, the inhibitory effects of those compounds on K562/ADR, Du-145, Hela, MCF-7 and HepG2 cell lines were evaluated by MTT assay. Among them, compound 15ß-hydroxy-20(R)-panaxatriol (4) exhibited selective inhibitory effects on human leukaemic progenitor cells K562/ADR through arresting cell cycle, which was associated with obvious decrease of cyclin B1, cyclin D1 and cyclin-dependent kinase (CDK) 1/2/4/6 protein expression.

Arvensic acids A-D, novel heptasaccharide glycosidic acids as the alkaline hydrolysis products of crude resin glycosides from Convolvulus arvensis.

In this study, a resin glycoside fraction with cytotoxic activity was isolated from the alcoholic extract of C. arvensis whole plants. To describe the chemical feature of the resin glycosides, the fraction was alkaline hydrolyzed and four novel glycosidic acids, named arvensic acids A-D (1-4), were isolated. Their structures were thoroughly elucidated on the basis of spectroscopic data and chemical evidences. They all possess a same heptasacharride core, consisting of one D-fucose, two L-rhamnose and four d-glucose units. The difference among these glycosidic acids was placed on the aglycone, which is 12S-hydroxypentadecanoic acid for 1, 12S-hydroxyhexadecanoic acid for 2, 3S,12S-dihydroxypentadecanoic acid for 3, and 3S,12S- dihydroxyhexadecanoic acid for 4. These aglycones are rarely found in the structures of resin glycosides and are firstly identified in the genus Convolvulus.

Benzyl sulforaphane is superior to sulforaphane in inhibiting the Akt/MAPK and activating the Nrf2/ARE signalling pathways in HepG2 cells.

OBJECTIVES: Sulforaphane (SFN), an isothiocyanate found in cruciferous vegetables, has been reported to own anticarcinogenic, antiinflammatory and cancer chemopreventive properties. Benzyl sulforaphane (BSFN) was a derivative of SFN which was designed and synthesized by our laboratory. Here, the cancer prevention and anticancer effects of BSFN on human hepatoma (HepG2) cells were investigated. METHODS: The following effects of BSFN on components of the mitochondrial apoptotic pathway were examined: generation of reactive oxygen species and mitochondrial membrane potential (ΔΨm) changes by flow cytometry, the expression changes of Bcl-2 family proteins and Akt/MAPK proteins by western blot. The protein levels of Nrf2 and Keap1 were also tested via Western blot. The effects of BSFN on Nrf2 nuclear translocation and ARE-reporter gene activity were examined by fluorescence microscope and multifunctional spectrophotometer. KEY FINDINGS: Benzyl sulforaphane could induce cell apoptosis by mitochondrion-dependent pathway, which inhibited HepG2 cells growth in a manner of time- and concentration -dependent. Furthermore, BSFN could inhibit the Akt/MAPK and activate the Nrf2/ARE pathway in HepG2 cells. CONCLUSIONS: Benzyl sulforaphane was superior to SFN in inhibiting Akt/MAPK and activating Nrf2/ARE signalling pathways in HepG2 cells, which indicated that BSFN could be a safe therapeutic strategy for the prevention and treatment of liver cancer.

Activated production of silent metabolites from marine-derived fungus Penicillium citrinum.

As an attempt to utilize of rare earth elements as a novel method to activate the silent genes in fungus, the marine-derived fungus Penicillium citrinum was cultured under ordinary laboratory fermentation conditions in the presence of scandium chloride (ScCl3, 50 µM), and chemical investigation led to the isolation and characterization of three new peptide derivatives (1-3), along with four known pyrrolidine alkaloids (4-7). Those structures were elucidated by spectroscopic data interpretation, as well as chemical reactions. Comparative metabolic profiling of the culture extracts (with/without scandium chloride) indicated that compounds 1-3 scarcely detected in the absence of ScCl3. In addition, the antibacterial and cytotoxic activities of all isolated products were evaluated.

Biotransformation of 20(S)-protopanaxatriol by Mucor racemosus and the anti-cancer activities of some products.

OBJECTIVE: To produce new derivatives of 20(S)-protopanaxatriol by fungal biotransformation. RESULT: Biotransformation of 20(S)-protopanaxatriol (1) by Mucor racemosus AS 3.205 afforded six products. Their structures were elucidated on the basis of extensive spectroscopic analyses. M. racemosus could selectively catalyze dehydrogenation at C-12 and further hydroxylation at C-7, C-11, and C-15, as well as rearrangement of double bond at C-26. Two of these new compounds exhibited potent inhibitory activity against SH-SY5Y and HepG2 cell lines. CONCLUSION: Biotransformation by M. racemosus AS 3.205 was an effective approach to produce new derivatives of 20(S)-protopanaxatriol.

Acetylcholinesterase inhibitory dimeric indole derivatives from the marine actinomycetes Rubrobacter radiotolerans.

Investigation of the bioactive secondary metabolites of the marine actinomycetes Rubrobacter radiotolerans led to the isolation and characterization of two naturally rare dimeric indole derivatives (1 and 2). The structures of these new compounds were elucidated by spectroscopic data interpretation, and the absolute configurations were assigned by CD calculations. The acetylcholinesterase (AchE) inhibitory activity of compounds 1 and 2 was evaluated, both of which showed moderate activity with IC50 values of 11.8 and 13.5µM, respectively.

Microbial transformation of 20(S)-protopanaxatriol by Mucor spinosus.

Microbial transformation of 20(S)-protopanaxatriol (1) by Mucor spinosus afforded two new and eight known metabolites. The structures of the metabolites were identified as 12-oxo-20(S)-protopanaxatriol (2), 23,24-en-25-methoxyl-20(S)-protopanaxatriol (3), 29-hydroxyl-20(S)-protopanaxatriol (4), 20(S),24(S)-epoxy-dammaran-3ß,6α,12ß,25-triol (5), 12-oxo-27-hydroxyl-20(S)-protopanaxatriol (6), 12-oxo-26-hydroxyl-20(S)-protopanaxatriol (7), 12-oxo-23ß-hydroxyl-20(S)-protopanaxatriol (8), 12-oxo-11ß-hydroxyl-20(S)-protopanaxatriol (9), 12-oxo-15α-hydroxyl-20(S)-protopanaxatriol (10), and 12-oxo-25,26-en-15α-hydroxyl-20(S)-protopanaxatriol (11). Among them, 3 and 11 are new compounds. The metabolites 3, 10 and 11 showed the more potent inhibitory effects against seven cell lines than the substrate.

Biotransformation of 20(S)-protopanaxadiol by Aspergillus niger AS 3.1858.

The biotransformation of 20(S)-protopanaxadiol (1) by Aspergillus niger AS 3.1858 was conducted. Seven metabolites 26-hydroxyl-20(S)-protopanaxadiol (2); 23, 24-en-25-hydroxyl-20(S)-protopanaxadiol (3); 25, 26-en-20(S)-protopanaxadiol (4); (E)-20, 22-en-25-hydroxyl-20(S)-protopanaxadiol (5); 25, 26-en-24(R)-hydroxyl-20(S)-protopanaxadiol (6); 25, 26-en-24(S)-hydroxyl-20(S)-protopanaxadiol (7); and 23, 24-en-25-ethoxyl-20(S)-protopanaxadiol (8) were afforded. Among them, 6, 7, and 8 are new compounds. The chemical structures of these metabolites were elucidated based on extensive spectral data including 2D NMR and HRMS. In addition, the cytotoxicity of substrate and all transformed products was evaluated by MTT assay using a panel of seven human tumor cell lines (Du-145, Hela, K562, K562/ADR, SH-SY5Y, HepG2, and MCF-7 cells) and one normal cell line Vero.

Microbial transformation of 20(S)-protopanaxatriol by Absidia corymbifera and their cytotoxic activities against two human prostate cancer cell lines.

Seven hydroxylates of 20(S)-protopanaxatriol (1) transformed by Absidia corymbifera AS 3.3387 were isolated and identified by spectral methods including 2D-NMR. Among them, 7ß-hydroxyl-20(S)-protopanaxatriol (2), 7α-hydroxyl-20(S)-protopanaxatriol (3), and 7ß, 15α-dihydroxyl-20(S)-protopanaxatriol (7) are new compounds. The metabolites 2, 6, 7, and 8 showed the more potent inhibitory effects against DU-145 and PC-3 cell lines than the substrate.

Two novel hydroperoxylated products of 20(S)-protopanaxadiol produced by Mucor racemosus and their cytotoxic activities against human prostate cancer cells.

Microbial transformation of 20(S)-protopanaxadiol (1) by Mucor racemosus AS 3.205 yielded two novel hydroperoxylated metabolites and three known hydroxylated metabolites. The structures of the metabolites were identified as 26-hydroxyl-20(S)-protopanaxadiol (2), 23,24-en-25-hydroxyl-20(S)-protopanaxadiol (3), 25,26-en-24(R)-hydroperoxyl-20(S)-protopanaxadiol (4), 23,24-en-25-hydroperoxyl-20(S)-protopanaxadiol (5), and 25-hydroxyl-20(S)-protopanaxadiol (6). 4 and 5 are new compounds. Metabolites 2, 4, and 5 showed the more potent inhibitory effects against DU-145 and PC-3 cell lines than the substrate.

Microbial transformation of 20(S)-protopanaxadiol by Absidia corymbifera. Cytotoxic activity of the metabolites against human prostate cancer cells.

Biotransformation of 20(S)-protopanaxadiol (1) by the fungus Absidia corymbifera AS 3.3387 yielded five metabolites (2-6). On the basis of spectroscopic data analyses, the metabolites were identified as 26-hydroxyl-20(S)-protopanaxadiol (2), 23, 24-en-25-hydroxyl-20(S)-protopanaxadiol (3), 25-hydroxyl-20(S)-protopanaxadiol (4), 7ß-hydroxyl-20(S)-protopanaxatriol (5), and 7-oxo-20(S)-protopanaxatriol (6), respectively. Among them, 5 and 6 are new compounds. These results indicated that A. corymbifera AS 3.3387 could catalyze the side-chain oxidation-reduction, 7ß hydroxylation, and the specific C-7 dehydrogenation of derivatives of 20(S)-protopanaxadiol. The metabolites 2, 5, and 6 showed the more potent inhibitory effects against DU-145 and PC-3 cell lines than the substrate.

A simple method for the isolation and purification of resveratrol from Polygonum cuspidatum.

Resveratrol, a polyphenol compound with strong biological activity, has been widely used in medicine, health products and cosmetic industries. It is also the main active component of Polygonum cuspidatum, a well-known traditional Chinese medicine. We developed a simple and effective method for the preparation of resveratrol from P. cuspidatum. The whole preparative process consisted of reflux extraction, filtering, hydrolyzing, liquid-liquid extraction and eluting. Filtering is to remove non polar or less polar compounds and debris fragments from the extract. Hydrolyzing is to transform polydatin to resveratrol to improve the yield of resveratrol. Eluting is to remove impurities including strong acidic and water-soluble compounds. By acid hydrolysis of glycoside (polydatin), the yield of resveratrol increased about 4-fold. The extraction recovery in different stages was high, and the content of resveratrol in the final product was over 73.8%. Compared with other methods reported, this technology is eco-friendly, easier to perform, and also has a lower cost.

Cytotoxic constituents of chinese propolis.

A pair of new flavanol racemates (1a and 1b) and a new flavanol racemic mixture (2) were isolated from crude propolis from Henan Province, People's Republic of China. Also obtained were nine known compounds, including two flavones, four flavonols, two flavanols, and isoferulic acid. Spectroscopic analysis was employed to assign the structures of these new compounds and the absolute configurations of 1a and 1b. Cytotoxicity of the isolated compounds against the HeLa human cervical carcinoma cancer cell line was evaluated, with only compounds 1a, 1b, 2, and rhamnetin (3) being active.

Cytotoxic polyprenylated xanthones from the resin of Garcinia hanburyi.

Twelve new xanthones (1-12), a pair of new natural products (13 and 14), and 18 known related compounds were isolated from the resin of Garcinia hanburyi. The structures of 1-14 were elucidated by detailed spectroscopic analyses. A cytotoxic assay of the isolated compounds revealed that, with the exception of 2, these compounds were active against the HeLa tumor cell line.

Cytotoxic diterpenoids from Euphorbia helioscopia.

Four new jatrophane-type diterpenoids (1-4), together with 16 known related compounds, were isolated from the Chinese medicinal plant Euphorbia helioscopia. The structures of 1-4 were determined on the basis of spectroscopic and chemical methods. Cytotoxicity of the isolated compounds against HeLa and MDA-MB-231 cells was evaluated, with only helioscopinolide A (5) and euphornin (3a) being active.