Biotransformation of Ursonic Acid by Aspergillus ochraceus and Aspergillus oryzae to Discover Anti-Neuroinflammatory Derivatives.

Biotransformation of ursonic acid (1) by two fungal strains Aspergillus ochraceus CGMCC 3.5324 and Aspergillus oryzae CGMCC 3.407 yielded thirteen new compounds (4, 5, 7-10, and 13-19), along with five recognized ones. The structural details of new compounds were determined through spectroscopic examination (NMR, IR, and HR-MS) and X-ray crystallography. Various modifications, including hydroxylation, epoxidation, lactonization, oxygen introduction, and transmethylation, were identified on the ursane core. Additionally, the anti-neuroinflammatory efficacy of these derivatives was assessed on BV-2 cells affected by lipopolysaccharides. It was observed that certain methoxylated and epoxylated derivatives (10, 16, and 19) showcased enhanced suppressive capabilities, boasting IC50 values of 8.2, 6.9, and 5.3 µM. Such ursonic acid derivatives might emerge as potential primary molecules in addressing neurodegenerative diseases.

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.

Biotransformation of Betulonic Acid by the Fungus Rhizopus arrhizus CGMCC 3.868 and Antineuroinflammatory Activity of the Biotransformation Products.

Biotransformation of betulonic acid (1) by Rhizopus arrhizus CGMCC 3.868 resulted in the production of 16 new (3, 5, 6, and 9-21) and five known compounds. Structures of the new compounds were established by analysis of spectroscopic data. Hydroxylation, acetylation, oxygenation, glycosylation, and addition reactions involved the C-20-C-29 double bond. Antineuroinflammatory activities of the obtained compounds in NO production were tested in lipopolysaccharides-induced BV-2 cells. Compared with the substrate betulonic acid, biotransformation products 3, 8, 9, 14, and 21 exhibited an improved inhibitory effect, with IC50 values of 10.26, 11.09, 5.38, 1.55, and 4.69 µM, lower than that of the positive control, NG-monomethyl-l-arginine.

Bioactive Constituents from the Bryophyta Hypnum plumaeforme.

Chemical investigation of the secondary metabolites of the whole plant of bryophyte Hypnum plumaeforme Wilson led to the isolation of a new pimarane-type diterpenoid, momilactone F (1), along with seventeen known compounds. Their chemical structures were elucidated based on massive spectroscopic data. The allelopathic and antifungal properties were evaluated. Among them, momilactone F (1), acrenol (2),[11] momilactones A (3) and B (4) showed significant allelopathic activity against Samolus parviflorus Raf. and Lactuca sativa L. var. angustana Irish, as well as selected antifungal property against crop pathogenic fungi strains. On the other hand, 8(14)-podocarpen-13-on-18-oic acid (8) exhibited strong promoting activity on the growth of L. sativa L. var. angustana Irish. The present investigation provided new insights for developing of H. plumaeforme for further application as a potential agricultural tool.

Glycosidic Acids with Unusual Aglycone Units from Convolvulus arvensis.

Six new glycosidic acids, arvensic acids E-J (1-6), were obtained from a glycosidic acid fraction afforded by alkaline hydrolysis of the crude resin glycosides from Convolvulus arvensis whole plants. Their structures were established from the spectroscopic data obtained and by chemical evidence. They were defined as heptasaccharides or hexasaccharides, comprising d-fucose, d-glucose, and l-rhamnose units. Compounds 1, 3, and 5 were assigned the 11 S-hydroxyheptadecanoic acid as the aglycone, while compounds 2, 4, and 6 were found to possess 11 S-hydroxyhexadecanoic acid as the aglycone. Compounds 1, 3, and 5 are the first representatives of resin glycosides with 11 S-hydroxyheptadecanoic acid as the aglycone.

Medicinal uses, pharmacology, and phytochemistry of Convolvulaceae plants with central nervous system efficacies: A systematic review.

Central nervous system (CNS) disorders play a major impact on individual lives and place a severe strain on health care resources. Convolvulaceae is a family comprising approximately 1,600-1,700 species grouped in 55-60 genera, and many species are reported to have an effect on CNS functions. A systematic review of the literature studies was carried out to summarize available evidences on Convolvulaceae plants with CNS efficacies. This review is based on various data sources such as Google Scholar, Web of Science, Scopus, PubMed, and Wanfang Data. A total of 200 related articles were included in this review. According to the research result, 54 Convolvulaceae species are suggested to display CNS efficacies historically, and 46 species have been evaluated for their CNS efficacies. In addition, 67 compounds from 16 Convolvulaceae species are recognized to possess CNS efficacies. Despite great progress made through pharmacology and phytochemistry studies on CNS active Convolvulaceae species, more exploratory research is needed to gain a better understanding of the CNS efficacies of this plant family.

(R)-panaxadiol by whole cells of filamentous fungus Absidia coerulea AS 3.3382.

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-7ß- hydroxyl-20(R)-panaxadiol (2), 3-oxo-22ß-hydroxyl-20(R)-panaxadiol (3), 3-oxo- 7ß,22ß-dihydroxyl-20(R)-panaxadiol (4), 3-oxo-7ß,24ß-dihydroxyl-20(R)-panaxadiol (5), and 3-oxo-7ß,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.

Isolation of evolvulic acids B and C, two new components of crude resin glycoside fraction from Evolvulus alsinoides.

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 3S,11R,14R-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.

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 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.

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.

Ingenane diterpenoids from Euphorbia esula.

An extensive study of metabolites present in Euphorbia esula led to isolation of 16 ingenane diterpenoids 1-16 together with the known ingenane derivative 17 and four known cycloartane triterpenoids. Their structures were elucidated on the basis of spectroscopic studies and comparison with known related compounds. All the compounds were assayed for their inhibitory activity against human HeLa cervical cancer cell line.

NMR spectral assignments of isoprenylated flavanones from Sophora tonkinensis.

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 ((1)H-(1)H COSY, HSQC, HMBC, and ROESY).

Structure elucidation and NMR spectral assignments of three new lignan glycosides from Akebia trifoliata.

Three new lignan glycosides (1-3) were isolated from the stems of Akebia trifoliata. Their structures were elucidated as (7R,8R,7'R,8'R)3,3',5,5'tetramethoxy-4,4'dihydroxy-7,9':7',9-diepoxylignan-4-O-beta-D-glucopyranoside (1), (7S,8S,8'R)-4,4',9-trihydroxy-3,3',5,5'-tetramethoxy-7,9'-epoxylignan-7'-one 9-O-beta-D-glucopyranoside (2), (7R,8R,8'S)-4,4',9-trihydroxy3,3',5,5'-tetramethoxy-7,9'-epoxylignan-7'-one 9-O-beta-D-glucopyranoside (3) by spectral analyses, primarily NMR, MS and CD. The NMR assignments for the compounds were carried out using 1H, 13C, DEPT, COSY, HSQC, HMBC and ROESY NMR experiments.

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.

[Study of chemical constituents in active parts of Mentha spicata III].

OBJECTIVE: To study the chemical constituents of Mentha spicata. METHOD: The chemical constituents were isolated by silica gel column chromatography, and identified by physical and chemical characters and spectroscopic analysis. RESULT: 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). CONCLUSION: 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.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-glucoside exerted protective effects on diabetic nephropathy in mice with hyperglycemia induced by streptozotocin.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-glucoside (TSG), an active component from the functional and medicinal herb Polygonum multiflorum Thunb, has the capacity of blocking angiotensin II (ANG II) signaling, a pathway within the renin-angiotensin system (RAS) which plays a critical role in the development of diabetic nephropathy (DN), and blockade of the RAS is currently used for the treatment of DN. Here we investigated the beneficial effect of TSG therapy on renal damage in the streptozotocin (STZ)-induced diabetes model. The STZ-treated C57BL/6J diabetic mice developed progressive albuminuria and renal tubular interstitial fibrosis within 10 weeks, accompanied by increased production of ANG II, fibronection, TGF-ß, CTGF, TNF-α, RANTES and MCP-1 and decreased expression of slit diaphragm proteins in the kidney. The treatment of the diabetic mice with a TSG ameliorated kidney mass increase prevented albuminuria, and reduced tubular interstitial fibrosis. The TSG treatment suppressed the induction of fibronection, CTGF, TGF-ß, and MCP-1 and reversed the decline of slit diaphragm proteins Neph-1, ZO-1, and FAT-1. These were accompanied by blockade of renal renin and ANG II accumulation induced by hyperglycemia. These data demonstrated that the inhibition of the RAS with TSG effectively prevented renal injury in diabetic nephropathy.

Characterization of pumpkin polysaccharides and protective effects on streptozotocin-damaged islet cells.

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.

UPLC-Q-TOF/MS-based screening and identification of two major bioactive components and their metabolites in normal and CKD rat plasma, urine and feces after oral administration of Rehmannia glutinosa Libosch extract.

Rehmannia glutinosa is a widely used traditional Chinese medicine (TCM) in clinical practice to tackle chronic kidney disease for thousands of years. However, the in vivo metabolism of its two major bioactive components (catalpol and acteoside) remains unknown. In this paper, a highly sensitive, rapid and robust ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) with MetaboLynx™ software combined with mass defect filtering (MDF) method was established. This validated analysis method was successfully applied to investigate the in vivo metabolic profiles of R. glutinosa extract in normal and chronic kidney disease (CKD) rats. The results showed that a total of 17 metabolites of two parent compounds in normal rats in vivo were tentatively detected and identified according to the characteristics of their protonated ions and relevant literature. While 11 of the metabolites were observed in the CKD rat samples. These metabolites suggested that catalpol was firstly deglycosylated to its aglycone and subsequently to two main metabolites (M1 and M4) by conjugation and hydrogenation respectively and acteoside was mainly metabolized by O-glucuronide conjugation and O-sulphate conjugation. In conclusion, this study showed an insight into the metabolism of R. glutinosa extract in vivo and the proposed metabolic pathways of bioactive components might play a key role in further pharmacokinetic experiments evaluations.

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.