In vitro biological evaluation and in silico insights into the antiviral activity of standardized olive leaves extract against SARS-CoV-2.

There is still a great global need for efficient treatments for the management of SARS-CoV-2 illness notwithstanding the availability and efficacy of COVID-19 vaccinations. Olive leaf is an herbal remedy with a potential antiviral activity that could improve the recovery of COVID-19 patients. In this work, the olive leaves major metabolites were screened in silico for their activity against SARS-CoV-2 by molecular docking on several viral targets such as methyl transferase, helicase, Plpro, Mpro, and RdRp. The results of in silico docking study showed that olive leaves phytoconstituents exhibited strong potential antiviral activity against SARS-CoV-2 selected targets. Verbacoside demonstrated a strong inhibition against methyl transferase, helicase, Plpro, Mpro, and RdRp (docking scores = -17.2, -20, -18.2, -19.8, and -21.7 kcal/mol.) respectively. Oleuropein inhibited 5rmm, Mpro, and RdRp (docking scores = -15, -16.6 and -18.6 kcal/mol., respectively) respectively. Apigenin-7-O-glucoside exhibited activity against methyl transferase and RdRp (docking score = -16.1 and -19.4 kcal/mol., respectively) while Luteolin-7-O-glucoside inhibited Plpro and RdRp (docking score = -15.2 and -20 kcal/mol., respectively). The in vitro antiviral assay was carried out on standardized olive leaf extract (SOLE) containing 20% oleuropein and IC50 was calculated. The results revealed that 20% SOLE demonstrated a moderate antiviral activity against SARS-CoV-2 with IC50 of 118.3 µg /mL. Accordingly, olive leaf could be a potential herbal therapy against SARS-CoV-2 but more in vivo and clinical investigations are recommended.

(±)-Gentiovarisin A and gentiovarisin B, unusual secoiridoid dimer skeletons from gentiopicroside.

Gentiana scabra, a famous traditional Chinese medicine (TCM), has been documented in Chinese Pharmacopoeia for the treatment of hepatitis. Its index component gentiopicroside could not be detected in the decoction, which suggested that the quality control of the TCM with this ingredient needs attention. The transformed products were obtained from gentiopicroside, mimicking the traditional process of G. scabra. Further investigation of the heat-transformed products yielded two secoiridoid dimers, gentiovarisin A (1) and B (2), with an unprecedented 6/6/6/6/6-fused pentacyclic skeletons. Their structures were elucidated by extensive spectroscopic analyses and single-crystal X-ray diffraction analysis, and the absolute configurations of 1 were confirmed as (+)-1 and (-)-1 by ECD method. Plausible transformation pathways of the isolates were also proposed. Compounds 1 and 2 exhibited in vitro hepatoprotective activity similar to gentiopicroside, while (+)-1 displayed a more potent hepatoprotective activity than N-Acetyl-L-cysteine.

A comparative study of echinacoside, oleuropein content and antioxidant properties of different solvent extracts from Syringa pubescens Turcz.

Syringa pubescens Turcz is commonly used folk medicinal herb in west of Henan Province of China. In this work, water and various concentration of methanol, ethanol and acetone in water were used as solvent to extract echinacoside and oleuropein from S. pubescens. The antioxidant properties of different extracts were evaluated using various in vitro assays. The highest yields of echinacoside and oleuropein were obtained by using the 60% aqueous methanol and 80% aqueous ethanol, respectively. The extracts of water, aqueous ethanol or methanol showed strong antioxidant abilities. Furthermore, the high correlation between echinacoside content and antioxidant properties was found. The contribution of oleuropein content was not significant to antioxidant abilities. These findings indicate that S. pubescens can be used as a new natural antioxidant resource.

Biological Profile of Two Gentiana lutea L. Metabolites Using Computational Approaches and In Vitro Tests.

Natural products have been the main source of bioactive molecules for centuries. We tested the biological profile of two metabolites extracted from Gentiana lutea L. by means of computational techniques and in vitro assays. The two molecules (loganic acid and gentiopicroside) were tested in silico using an innovative technique, named Inverse Virtual Screening (IVS), to highlight putative partners among a panel of proteins involved in inflammation and cancer events. A positive binding with cyclooxygenase-2 (COX-2), alpha-1-antichymotrypsin, and alpha-1-acid glycoprotein emerged from the computational experiments and the outcomes from the promising interaction with COX-2 were confirmed by Western blot, highlighting the reliability of IVS in the field of the natural products.

Picroside II Improves Severe Acute Pancreatitis-Induced Hepatocellular Injury in Rats by Affecting JAK2/STAT3 Phosphorylation Signaling.

Picroside II is an important ingredient agent in Traditional Chinese medicine and hoped to reduce hepatocellular injury caused by severe acute pancreatitis (SAP). An SAP-induced hepatocellular injury model was established in rats by using pentobarbital sodium. 27 rats were divided into 3 groups: the sham group (SG), model group (MG), and Picroside groups (PG). SAP-induced hepatocellular injury was assessed using hematoxylin and eosin staining. We measured hepatocellular enzymes (amylase (AMY), alanine aminotransferase (ALT), and aspartate aminotransferase (AST)), oxidative stress factors (superoxidase dismutase (SOD) and malondialdehyde (MDA)), and inflammatory factors (tumor necrosis factor α (TNF-α), interleukin- (IL-) 6, and IL-10), apoptotic factors (BAX and cleaved caspase 3), and inflammatory signaling (Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3), p-JAK2, and p-STAT3) in hepatocellular tissues. The SAP-induced hepatocellular injury model was successfully established. Picroside II treatment repaired hepatocellular injury by reducing the activities of AMY, ALT, and AST; reducing the levels of MDA, TNF-α, IL-1, IL-6, p-JAK2, p-STAT3, BAX, and cleaved caspase 3; and increasing the levels of SOD and IL-10. Picroside II exerted protective function for the SAP-induced hepatocellular injury model. Picroside II improved SAP-induced hepatocellular injury and antioxidant and anti-inflammatory properties by affecting JAK2/STAT3 phosphorylation signaling.

Chemistry, Pharmacology and Therapeutic Potential of Swertiamarin - A Promising Natural Lead for New Drug Discovery and Development.

Swertiamarin, a seco-iridoid glycoside, is mainly found in Enicostemma littorale Blume (E. littorale) and exhibits therapeutic activities for various diseases. The present study aimed to provide a review of swertiamarin in terms of its phytochemistry, physicochemical properties, biosynthesis, pharmacology and therapeutic potential. Relevant literature was collected from several scientific databases, including PubMed, ScienceDirect, Scopus and Google Scholar, between 1990 and the present. This review included the distribution of swertiamarin in medicinal plants and its isolation, characterization, physicochemical properties and possible biosynthetic pathways. A comprehensive summary of the pharmacological activities, therapeutic potential and metabolic pathways of swertiamarin was also included after careful screening and tabulation. Based on the reported evidence, swertiamarin meets all five of Lipinski's rules for drug-like properties. Thereafter, the physicochemical properties of swertiamarin were detailed and analyzed. A simple and rapid method for isolating swertiamarin from E. littorale has been described. The present review proposed that swertiamarin may be biosynthesized by the mevalonate or nonmevalonate pathways, followed by the seco-iridoid pathway. It has also been found that swertiamarin is a potent compound with diverse pharmacological activities, including hepatoprotective, analgesic, anti-inflammatory, antiarthritis, antidiabetic, antioxidant, neuroprotective and gastroprotective activities. The anticancer activity of swertiamarin against different cancer cell lines has been recently reported. The underlying mechanisms of all these pharmacological effects are diverse and seem to involve the regulation of different molecular targets, including growth factors, inflammatory cytokines, protein kinases, apoptosis-related proteins, receptors and enzymes. Swertiamarin also modulates the activity of several transcription factors, and their signaling pathways in various pathological conditions are also discussed. Moreover, we have highlighted the toxicity profile, pharmacokinetics and possible structural modifications of swertiamarin. The pharmacological activities and therapeutic potential of swertiamarin have been extensively investigated. However, more advanced studies are required including clinical trials and studies on the bioavailability, permeability and administration of safe doses to offer swertiamarin as a novel candidate for future drug development.

Iridoid compounds from the aerial parts of Swertia mussotii Franch. with cytotoxic activity.

One new secoiridoid compound swertiamarin B (1), along with a known compound lytanthosalin (2), were isolated from ethanol extract of the aerial parts of Swertia mussotii. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. All compounds were first isolated from the Swertia genus. Their antitumor activities were evaluated for four human tumor cell lines (HCT-116, HepG2, MGC-803 and A549). Compounds 1 and 2 showed excellent cytotoxic activities toward the MGC-803 cell lines with IC50 values 3.61 and 12.04 µM, respectively.

Hydroxytyrosol and Oleuropein-Enriched Extracts Obtained from Olive Oil Wastes and By-Products as Active Antioxidant Ingredients for Poly (Vinyl Alcohol)-Based Films.

Oxidative stability of food is one of the most important parameters affecting integrity and consequently nutritional properties of dietary constituents. Antioxidants are widely used to avoid deterioration during transformation, packaging, and storage of food. In this paper, novel poly (vinyl alcohol) (PVA)-based films were prepared by solvent casting method adding an hydroxytyrosol-enriched extract (HTyrE) or an oleuropein-enriched extract (OleE) in different percentages (5, 10 and 20% w/w) and a combination of both at 5% w/w. Both extracts were obtained from olive oil wastes and by-products using a sustainable process based on membrane technologies. Qualitative and quantitative analysis of each sample carried out by high performance liquid chromatography (HPLC) and nuclear resonance magnetic spectroscopy (NMR) proved that the main components were hydroxytyrosol (HTyr) and oleuropein (Ole), respectively, two well-known antioxidant bioactive compounds found in Olea europaea L. All novel formulations were characterized investigating their morphological, optical and antioxidant properties. The promising performances suggest a potential use in active food packaging to preserve oxidative-sensitive food products. Moreover, this research represents a valuable example of reuse and valorization of agro-industrial wastes and by-products according to the circular economy model.

Sweritranslactone D, a hepatoprotective novel secoiridoid dimer with tetracyclic lactone skeleton from heat-transformed swertiamarin.

Swertia mileensis, known as Qing-Ye-Dan (QYD), has been documented in Chinese Pharmacopoeia to cure hepatitis. Interestingly, its announced main active component, swertiamarin, could not be detected in the decoction, which indicated that the efficacy of QYD might be attributed to heat-transformed products of swertiamarin (HTPS). Further investigation on HTPS led to the isolation of sweritranslactone D (1), a novel secoiridoid dimer possessing a tetracyclic lactone skeleton, with better hepatoprotective activity than N-acetyl-L-cysteine in vitro.

In-vitro cytotoxicity in relation to chemotypic diversity in diploid and tetraploid populations of Gentiana kurroo Royle.

ETHNOPHARMACOLOGICAL RELEVANCE: Gentiana kurroo is a multipurpose critically endangered medicinal herb prescribed as medicine in Ayurveda in India and exhibits various pharmacological properties including anti-cancer activity. The species is rich repository of pharmacologically active secondary metabolites together with secoiridoidal glycosides. AIM OF THE STUDY: The study aimed to investigate the chemical diversity in different populations/cytotypes prevailing in G. kurroo to identify elite genetic stocks in terms of optimum accumulation/biosynthesis of desired metabolites and having higher in-vitro cytotoxicity potential in relation to chemotypic diversity. MATERIAL AND METHODS: The wild plants of the species were collected from different ranges of altitudes from the Kashmir Himalayas. For cytological evaluation, the standard meiotic analysis was performed. The standard LC-MS/MS technique was employed for phytochemical analysis based on different marker compounds viz. sweroside, swertiamarin, and gentiopicroside. Different tissues such as root-stock, aerial parts, and flowers were used for chemo-profiling. Further, the methanolic extracts of diploid and tetraploid cytotypes were assessed for cytotoxic activity by using MTT assay against four different human cancer cell lines. RESULTS: The quantification of major bioactive compounds based on tissue- and location-specific comparison, as well as in-vitro cytotoxic potential among extant cytotypes, was evaluated. The comprehensive cytomorphological studies of the populations from NW Himalayas revealed the occurrence of different chromosomal races viz. n = 13, 26. The tetraploid cytotype was hitherto unreported. The tissue-specific chemo-profiling revealed relative dominance of different phytoconstituents in root-stock. There was a noticeable increase in the quantity of the analyzed compounds in relation to increasing ploidy status along the increasing altitudes. The MTT assay of methanolic extracts of diploid and tetraploid cytotypes displayed significant cytotoxicity potential in tetraploids. The root-stock extracts of tetraploids were highly active extracts with IC50 value ranges from 5.65 to 8.53 µg/mL against HCT-116 colon cancer. CONCLUSION: The chemical evaluation of major bioactive compounds in diverse cytotypes from different plant parts along different altitudes presented an appreciable variability in sweroside, swertiamarin, and gentiopicroside contents. Additionally, the concentrations of these phytoconstituents varied for cytotoxicity potential among different screened cytotypes. This quantitative difference of active bio-constituents was in correspondence with the growth inhibition percentage of different tested cancer cell lines. Thus, the present investigation strongly alludes towards a prognostic approach for the identification of elite cytotypes/chemotypes with significant pharmacological potential.

Swertiamarin from Enicostemma littorale, counteracts PD associated neurotoxicity via enhancement α-synuclein suppressive genes and SKN-1/NRF-2 activation through MAPK pathway.

The elusive targets and the multifactorial etiology of Parkinson's disease (PD) have hampered the discovery of a potent drug for PD. Furthermore, the presently available medications provide only symptomatic relief and have failed to mitigate the pathogenesis associated with PD. Therefore, the current study was aimed to evaluate the prospective of swertiamarin (SW), a secoiridoid glycoside isolated from a traditional medicinal plant, Enicostemma littorale Blume to ameliorate the characteristic features of PD in Caenorhabditis elegans. SW (25 µM) administration decreased the α-synuclein (α-syn) deposition, inhibited apoptosis and increased dopamine level mediated through upregulating the expression of genes linked to ceramide synthesis, mitochondrial morphology and function regulation, fatty acid desaturase genes along with stress responsive MAPK (mitogen-activated protein kinase) pathway genes. The neuroprotective effect of SW was evident from the robust reduction of 6-hydroxydopamine (6-OHDA) induced dopaminergic neurodegeneration independent of dopamine transporter (dat-1). SW mediated translational regulation of MAPK pathway genes was observed through increase expression of SKN-1 and GST-4. Further, in-silico molecular docking analysis of SW with C. elegans MEK-1 showed a promising binding affinity affirming the in-vivo results. Overall, these novel finding supports that SW is a possible lead for drug development against the multi- factorial PD pathologies.

Hepatoprotective activity assessment of amino acids derivatives of picroside I and II.

Picrorhiza kurroa has a long medicinal history as a traditional medicinal plant in China and India that is widely used in clinical treatments. It is a common treatment for liver diseases, fever, diarrhoea, indigestion, and some other diseases. Modern pharmacological studies proved that P. kurroa rhizomes have high levels of picroside I and II, which were identified as main constituents with anti-inflammatory and hepatoprotective activities. In our study, we used picroside I and II as the lead compounds to generate derivatives by reactions with Boc-valine or Boc-proline, which underwent dehydration and condensation with the hydroxyl groups in the lead compounds in the presence of coupling reagent N,N'-dicyclohexylcarbodiimide. We synthesized 11 derivatives and examined their hepatoprotective effects in vitro by assessing the proliferation rates of H2 O2 -exposed HepG2 cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. We found that some derivatives promoted higher proliferation rates in HepG2 cells than the natural compounds before derivatization, suggesting that those derivatives possessed an improved hepatoprotective capacity. The novel derivatization strategy for picrosides had the additional benefit that the esterification of their hydroxyl groups created derivatives not only with increased stability but also with improved pharmacokinetic properties and potentially prolonged half-life.

Establishment and elicitation of transgenic root culture of Plantago lanceolata and evaluation of its anti-bacterial and cytotoxicity activity.

Hairy root induction in Plantago lanceolata was optimized to take advantage of transformed root cultures. The highest frequency of transformation was achieved using leaf explant, A4 strain, pre-cultivation of explant, 150 µM Acetosyringone, 5 min inoculation, half-strength Murashige and Skoog basal medium as co-cultivation, and half-strength Gamborg's basal medium as a selective medium with 3% sucrose. Among the studied compound encompassing gallic acid, catalpol and apigenin, only the production of gallic acid in hairy roots was affected by 20 mg L-1 AgNO3 and 100 mg L-1 chitosan at 24 hr which yielded 7.63, 4.76-fold increase in its content, respectively. The methanolic extracts of hairy roots elicited by 20 mg L-1 AgNO3 exhibited anti-bacterial activity (MIC and MBC = 25 mg mL-1) against Klebsiella pneumoniae, Proteus vulgaris and Salmonella typhi and anti-bacterial potential of non-elicited hairy roots of P. lanceolata (MIC = 25 mg mL-1 and MBC = 35 mg mL-1) were more active against Klebsiella pneumoniae and P. vulgaris than other bacteria. The methanolic extracts of the P. lanceolata hairy roots demonstrated significant cytotoxic activity on colorectal carcinoma cell line (SW-480) with IC50 = 250.65 ± 6.8 µg mL-1 in comparison to human embryonic kidney (HEK-293) with IC50 = 5263.65 ± 4.6 µg mL-1. Plantago lanceolata hairy roots showed important biological activity explaining its role in traditional medicine.

Gentiopicroside prevents alcoholic liver damage by improving mitochondrial dysfunction in the rat model.

Gentianae Radix et Rhizoma is a medical plant that is widely cultivated in China, North Korea, Japan, and Russia, and gentiopicroside is one of its major active compounds. In this study, the hepatoprotective activity of gentiopicroside on rats with alcoholic liver damage (ALD) was evaluated using the transaminase and blood lipid levels and antioxidant capacity. The potential mechanism of hepatoprotective effect of gentiopicroside was evaluated by mitochondrial function detection, gas chromatography-mass spectrometry (GC-MS) metabolomic analysis, and anti-apoptosis analysis. Results showed that the gentiopicroside exhibited good hepatoprotective activity on rats with ALD by decreasing the transaminase levels, regulating the blood lipid levels, and increasing the antioxidant capacity. The potential mechanisms were related to regulating mitochondrial dysfunction by recovering mitochondrial membrane potential level, adenosine triphosphate concentration, activities of key enzymes in tricarboxylic acid cycle, and activities of complex I-V, regulating micromolecular metabolism and anti-apoptosis. These findings supported the further exploration of Gentianae Radix et Rhizoma as effective phytotherapy to prevent and treat ALD.

Secoiridoid Glucosides and Anti-Inflammatory Constituents from the Stem Bark of Fraxinus chinensis.

Qin Pi (Fraxinus chinensis Roxb.) is commercially used in healthcare products for the improvement of intestinal function and gouty arthritis in many countries. Three new secoiridoid glucosides, (8E)-4''-O-methylligstroside (1), (8E)-4''-O-methyldemethylligstroside (2), and 3'',4''-di-O-methyl-demethyloleuropein (3), have been isolated from the stem bark of Fraxinus chinensis, together with 23 known compounds (4-26). The structures of the new compounds were established by spectroscopic analyses (1D, 2D NMR, IR, UV, and HRESIMS). Among the isolated compounds, (8E)-4''-O-methylligstroside (1), (8E)-4''-O-methyldemethylligstroside (2), 3'',4''-di-O-methyldemethyloleuropein (3), oleuropein (6), aesculetin (9), isoscopoletin (11), aesculetin dimethyl ester (12), fraxetin (14), tyrosol (21), 4-hydroxyphenethyl acetate (22), and (+)-pinoresinol (24) exhibited inhibition (IC50 ≤ 7.65 µg/mL) of superoxide anion generation by human neutrophils in response to formyl-L-methionyl-L-leuckyl-L-phenylalanine/cytochalasin B (fMLP/CB). Compounds 1, 9, 11, 14, 21, and 22 inhibited fMLP/CB-induced elastase release with IC50 ≤ 3.23 µg/mL. In addition, compounds 2, 9, 11, 14, and 21 showed potent inhibition with IC50 values ≤ 27.11 µM, against lipopolysaccharide (LPS)-induced nitric oxide (NO) generation. The well-known proinflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6), were also inhibited by compounds 1, 9, and 14. Compounds 1, 9, and 14 displayed an anti-inflammatory effect against NO, TNF-α, and IL-6 through the inhibition of activation of MAPKs and IκBα in LPS-activated macrophages. In addition, compounds 1, 9, and 14 stimulated anti-inflammatory M2 phenotype by elevating the expression of arginase 1 and Krüppel-like factor 4 (KLF4). The above results suggested that compounds 1, 9, and 14 could be considered as potential compounds for further development of NO production-targeted anti-inflammatory agents.

Research on the Potential Mechanism of Gentiopicroside Against Gastric Cancer Based on Network Pharmacology.

BACKGROUND: Gastric cancer was still one of the commonly diagnosed cancer types and the third-most common cause of cancer-related death in the world. Gentiopicroside, which is extracted from the Gentianella acuta, is commonly used in both traditional treatment and modern clinical care; therefore, its anticancer effects have been attracted more attention. However, the systematic analysis of action mechanism of Gentiopicroside on gastric cancer (GC) has not yet been carried out. AIM: A network pharmacology-based strategy combined with molecular docking studies and in vitro validation was employed to investigate potential targets and molecular mechanism of Gentiopicroside against GC. MATERIALS AND METHODS: Potential targets of Gentiopicroside, as well as related genes of GC, were acquired from public databases. Potential targets, and signaling pathways were determined through bioinformatic analysis, including protein-protein interaction (PPI), the Gene Ontology (GO), and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Subsequently, molecular docking and cell experiments were performed to further verify the above findings. RESULTS: Our findings revealed that the anticancer activity of Gentiopicroside potentially involves 53 putative identified target genes. In addition, GO, KEGG, and network analyses revealed that these targets were associated with cell proliferation, metabolic process, and other physiological processes. Furthermore, we have proved that critical compound affected the expression of CCND1, CCNE1, p-AKT and p-P38 at protein levels. These findings provide an overview of the anticancer action of Gentiopicroside from a network perspective; meanwhile, it might also set an example for future studies of other materials used in traditional Chinese medicine (TCM). CONCLUSION: This study comprehensively illuminated the potential targets and molecular mechanism of Gentiopicroside against GC. It also provided a promising approach to uncover the scientific basis and therapeutic mechanism of TCM treating for disease.

New insight into the antigenotoxic activity of Gentiana lutea extracts - Protective effect against food borne mutagens.

Food mutagens formed from amino acids during heating of meat have the potential to induce serious consequences on human health. As a result, the identification of naturally occurring, genoprotective agents, is of great importance. The aim of this study was to chemically characterize a root and leaf extracts of Gentiana lutea and to investigate the antigenotoxic effects of extracts and pure constituents (gentiopicroside and mangiferin). Antigenotoxic effects were shown for combinations with the food borne mutagens IQ and PhIP using hepatoma HepG2 cells. Furthermore, their antioxidant activity and their capacity to modulate Nrf2 expression and affect the glutathione redox status were tested. Chemical analyses showed that the most abundant constituents found in root extract are gentiopicroside and sweroside. On the other hand, homoorientin and isovitexin were the dominant ones in leaf extract. Strong genoprotective activities of all tested compounds against both mutagens were observed in alkaline comet assays (up to 77% of tail intensity inhibition, p < 0.001). The protection against glutathione depletion was partially due to the radical scavenging activity and up-regulation of Nrf2 expression by the substances. The results of this study strongly encourage further investigations of the antimutagenic properties of G. lutea.

Investigation of a Medical Plant for Hepatic Diseases with Secoiridoids Using HPLC and FT-IR Spectroscopy for a Case of Gentiana rigescens.

Secoiridoids could be used as a potential new drug for the treatment of hepatic disease. The content of secoiridoids of G. rigescens varied in different geographical origins and parts. In this study, a total of 783 samples collected from different parts of G. rigescens in Yunnan, Sichuan, and Guizhou Provinces. The content of secoiridoids including gentiopicroside, swertiamarin, and sweroside were determined by using HPLC and analyzed by one-way analysis of variance. Two selected variables including direct selected and variable importance in projection combined with partial least squares regression have been used to establish a method for the determination of secoiridoids using FT-IR spectroscopy. In addition, different pretreatments including multiplicative scatter correction (MSC), standard normal variate (SNV), first derivative and second derivative (SD), and orthogonal signal correction (OSC) were compared. The results indicated that the sample (root, stem, and leaf) with total secoiridoids, gentiopicroside, swertiamarin, and sweroside from west Yunnan had higher content than samples from the other regions. The sample from Baoshan had more total secoiridoids than other samples for the whole medicinal plant. The best performance using FT-IR for the total secoiridoid was with the direct selected variable method involving pretreatment of MSC+OSC+SD in the root and stem, while in leaf, of the best method involved using original data with MSC+OSC+SD. This method could be used to determine the bioactive compounds quickly for herbal medicines.

Undescribed morroniside-like secoiridoid diglycosides with α-glucosidase inhibitory activity from Corni Fructus.

Corni Fructus, also known as the fruit of Cornus officinalis Sieb. et Zucc., has long been used as a traditional Chinese medicine and is widely consumed as a nutritional food in the form of function drink and wine. Recently, Corni Fructus has attracted considerable interest because of its anti-diabetic effects. A systematic phytochemical investigation of Corni Fructus was performed to find anti-diabetic components, which led to the isolation of 10 unreported iridoid glycosides, cornusdiglycosides A-J (1-8, 9a/9b and 10a/10b). Their chemical structures were determined through spectroscopic analysis (ultraviolet [UV], infrared [IR], high-resolution electrospray ionisation mass spectroscopy [HRESIMS], one-dimensional [1D] and two-dimensional [2D] nuclear magnetic resonance [NMR]). Such morroniside-type diglycosides were first reported from natural sources, and all isolates were evaluated for α-glucosidase inhibitory activity. The results showed that all compounds (1-10) exhibited α-glucosidase (from Saccharomyces cerevisiae) inhibitory activities with IC50 values ranging from 78.9 ± 4.09 to 162.2 ± 9.17 µM, whereas acarbose, the positive control, displayed α-glucosidase inhibitory activity with IC50 value of 118.9 ± 7.89 µM.

New Oleanane-type glycosides and secoiridoid glucoside from Aptandra zenkeri.

Four new saponins, camelliagenin A and B derivatives, and one new secoiridoid glucoside were isolated from the stem bark of Aptandra zenkeri Engl. (Aptandraceae) together with two known secoiridoid glucosides. Their structures were determined based on a combination of 1D- and 2D-NMR experiments techniques and HR-ESI-MS analysis. This is the first report on saponins in genus Aptandra.