Fruits Of Siraitia Grosvenorii Research Articles

Metabolism of Two Mogroside Isomers, Mogroside III and Mogroside IIIE, in Normal and Drug-Metabolizing Enzyme-Induced Rats.

Mogrosides III (1) and IIIE (2) are two important bioactive cucurbitane-type triterpenoid triglycosides in the edible fruits of Siraitia grosvenorii (Swingle), which are isomers and have only a minor difference in their structures. To clarify the effects of structural difference and drug-metabolizing-enzyme induction on their metabolism in vivo, their metabolites in normal rats and drug-metabolizing-enzyme-induced rats were tentatively identified and semiquantified by using the HPLC-DAD-ESI-IT-TOF-MSn technique. Totally, 76, 78, 96, and 121 metabolites of mogrosides were identified in the NIII (normal rats orally administered with mogroside III), NIIIE (normal rats orally administered with mogroside IIIE), EIII (drug-metabolizing-enzyme-induced rats orally administered with mogroside III), and EIIIE (drug-metabolizing-enzyme-induced rats orally administered with mogroside IIIE) groups, respectively. The metabolite differences among these groups indicated that their minor structural differences are responsible for the significant differences in their metabolites, and the induction of drug-metabolizing enzymes significantly increased the number of their metabolites. These findings would improve our understanding of the in vivo processes of mogrosides III and IIIE as well as their interactions with other food bioactive components or drugs.

Post-Ripening and Key Glycosyltransferase Catalysis to Promote Sweet Mogrosides Accumulation of Siraitia grosvenorii Fruits.

Sweet mogrosides are not only the primary bioactive ingredient in Siraitia grosvenorii fruits that exhibit anti-tussive properties and expectorate phlegm, but they are also responsible for the fruit's sweetness. Increasing the content or proportion of sweet mogrosides in Siraitia grosvenorii fruits is significant for improving their quality and industrial production. Post-ripening is an essential step in the post-harvest processing of Siraitia grosvenorii fruits, but the underlying mechanism and condition of post-ripening on Siraitia grosvenorii quality improvement need to be studied systematically. Therefore, this study analyzed the mogroside metabolism in Siraitia grosvenorii fruits under different post-ripening conditions. We further examined the catalytic activity of glycosyltransferase UGT94-289-3 in vitro. The results showed that the post-ripening process of fruits could catalyze the glycosylation of bitter-tasting mogroside IIE and III to form sweet mogrosides containing four to six glucose units. After ripening at 35 °C for two weeks, the content of mogroside V changed significantly, with a maximum increase of 80%, while the increase in mogroside VI was over twice its initial amount. Furthermore, under the suitable catalytic condition, UGT94-289-3 could efficiently convert the mogrosides with less than three glucose units into structurally diverse sweet mogrosides, i.e., with mogroside III as the substrate, 95% of it can converted into sweet mogrosides. These findings suggest that controlling the temperature and related catalytic conditions may activate UGT94-289-3 and promote the accumulation of sweet mogrosides. This study provides an effective method for improving the quality of Siraitia grosvenorii fruits and the accumulation of sweet mogrosides, as well as a new economical, green, and efficient method for producing sweet mogrosides.

Mogroside-Rich Extract From Siraitia grosvenorii Fruits Ameliorates High-Fat Diet-Induced Obesity Associated With the Modulation of Gut Microbiota in Mice.

Siraitia grosvenorii is a kind of medicinal food plant. The mogroside-rich extract (MGE) of its fruits can effectively ameliorate obesity, but the underlying mechanisms remain underexplored. In this study, we aimed to determine whether MGE can ameliorate obesity by protecting against the divergences of gut microbiota. Mice were challenged with a high-fat diet (HFD) and treated with MGE by oral gavage. Then, the characteristics of the gut microbiota were determined by 16S rDNA analysis. Our findings showed that MGE could significantly reduce body weight gain and fat tissue weight of the mice fed with HFD. Moreover, MGE markedly attenuated fatty liver, and improved glucose tolerance and insulin sensitivity. We further found that the gut microbiota structures were disturbed by HFD feeding. In particular, the abundance of Firmicutes was increased and the abundance of Bacteroidetes was decreased, resulting in an increased proportion of Firmicutes to Bacteroidetes (F/B), which contributes to obesity. Interestingly, the abnormal proportion of F/B of HFD feeding mice was restored to the level of control mice by MGE treatment. Additionally, the abundances of obesogenic microbiota, such as Ruminiclostridium and Oscillibacter were also decreased after MGE treatment. In summary, our findings demonstrate that MGE can modulate gut microbiota in obese mice and shed new light on how it alleviates obesity.

Regulating the gut microbiota and SCFAs in the faeces of T2DM rats should be one of antidiabetic mechanisms of mogrosides in the fruits of Siraitia grosvenorii

Ethnopharmacological relevanceThe Siraitia grosvenorii fruits extract (SG, in which mogrosides are the main components), considered as a non-nutritional sweetener, has an antidiabetic effect. Our previous studies have confirmed that an extract of mogrosides being rich in triterpene glycosides with 1–3 glucosyl residues, designated as low-polar S. grosvenorii glycosides (L-SGgly), had a significant antidiabetic effect. However, whether the mechanism through impacting on gut microbiota to exert the antidiabetic effect of mogrosides remains unclear. Aims of the studyTo explore the potential mechanism of mogrosides (SG and L-SGgly) on gut microbiota and faecal metabolites in the treatment of diabetes. Study design and MethodsIn this study, the effects of SG and L-SGgly on gut microbiota and faecal endogenous metabolites were explored by sequencing the 16S rRNA V3–V4 region of gut microbiota, and detecting with gas chromatography-mass spectrometry (GC-MS) and liquid chromatography quadrupole time-of-flight MS (LC-Q-TOF/MS), respectively. In particular, correlation analyses revealed how these influences affect the anti-hyperglycaemic effect, to give the underlying antidiabetic mechanisms of the mogrosides in S. grosvenorii fruits. ResultsAfter a 14-day treatment with SG and L-SGgly for type 2 diabetes mellitus (T2DM) rats induced by a high-fat diet (HFD) and streptozotocin (STZ), the disordered gut microbiota in the faeces of T2DM rats were recovered. At the same time, the short-chain fatty acids (SCFAs) concentration significantly increased and the deoxycholic acid and 1β-hydroxycholic acid content decreased in the faeces of T2DM rats. Moreover, correlation analyses provided the evidences that gut microbiota and its metabolites could be the target for exerting the anti-hyperglycaemic effects of SG and L-SGgly. Especially, Elusimicrobium, Lachnospiraceae_UCG-004, acetate, butyrate, and 1β-hydroxycholic acid would be the potential dominant bacteria and biomarkers for SG and L-SGgly in reducing the blood glucose and insulin resistance of T2DM rats. ConclusionIt is the first time that a mechanism of targeting on gut microbiota for the antidiabetic effect of mogrosides in S. grosvenorii fruits has been proposed.

Siraitia grosvenorii Residual Extract Attenuates Atopic Dermatitis by Regulating Immune Dysfunction and Skin Barrier Abnormality.

Atopic dermatitis is a persistent inflammatory skin disorder. Siraitia grosvenorii fruits (monk fruit or nahangwa in Korean, NHG) are used as a natural sweetener and as a traditional medicine for the treatment of asthma and bronchitis. We evaluated the activity of S. grosvenorii residual extract (NHGR) on allergic inflammation of atopic dermatitis in a Dermatophagoides farinae mite antigen extract (DfE)-treated NC/Nga murine model and in vitro. Oral administration of NHGR significantly reduced epidermal hyperplasia and inflammatory cell infiltration in the skin lesions of DfE-induced atopic dermatitis, as well as the dermatitis severity score. NHGR reduced serum immunoglobulin E levels. Splenic concentrations of IFN-γ, interleukin (IL)-4, IL-5, and IL-13 were reduced by NHGR administration. Immunohistofluorescence staining showed that NHGR administration increased the protein levels of claudin-1, SIRT1, and filaggrin in atopic dermatitis skin lesions. In addition, NHGR inhibited the phosphorylation of mitogen-activated protein kinases and decreased filaggrin and chemokine protein expression in TNF-α/IFN-γ-induced human keratinocytes. Moreover, NHGR also inhibited histamine in mast cells. The quantitative analysis of NHGR revealed the presence of grosvenorine, kaempferitrin, and mogrosides. These results demonstrate that NHGR may be an efficient therapeutic agent for the treatment of atopic dermatitis.

Prediction of the sweetening effect of Siraitia grosvenorii (luo han guo) fruits by two-dimensional quantitative NMR

During the last decade, dried fruits of Siraitia grosvenorii (luo han guo), also known as monk fruit, have become popular food ingredients. Luo han guo extracts, which are promoted as non-caloric natural sweeteners, are now incorporated into dietary supplements, soft drinks, and energy shakes. The compounds responsible for the sweetening effect are glycosylated cucurbitane-type triterpenoids, the so-called mogrosides. However, of the more than 40 known mogroside compounds, only 11-α-hydroxy-mogrosides exhibit a sweetening effect, whereas the other triterpenoids are non- or bitter-tasting. We have used two-dimensional quantitative NMR to determine selectively the content of 11-α-hydroxy-mogrosides in these dried fruits and thus to predict their sweetening potential. Homonuclear (H,H COSY) and heteronuclear (HSQC) methods were developed, validated, and compared. Both techniques were found suitable for the quality control of luo han guo fruits and extracts, the COSY experiment being advantageous with regard to accuracy, precision, and limit of quantification.

Safety of use of Monk fruit extract as a food additive in different food categories.

The EFSA Panel on Food Additives and Flavourings (FAF) provides a scientific opinion on the safety of Monk fruit extract proposed for use as a new food additive in different food categories. Monk fruit extracts are prepared by water extraction of the fruits of Siraitia grosvenorii. Cucurbitane glycosides, mogrosides, are the main components of the S. grosvenorii fruit and mogroside V is the main mogroside in the Monk fruit extract. Mogroside V is absorbed to some extent and is systemically bioavailable. Monk fruit extract containing 25% and 55% mogroside V were negative in the bacterial reverse mutation assay and did not induce structural and/or numerical chromosomal damage. However, the Panel noted that the in vitro toxicity studies including study with metabolic activation were not sufficiently informative to evaluate the genotoxic potential of the metabolites generated after microbial metabolism, including the aglycone. The effects on the testis observed in a 90‐day study with monk fruit extract‐52% mogroside V cannot be dismissed and the adversity of these effects cannot be ruled out. No effects on parental, reproductive or development toxicity were observed in a reproductive and developmental screening study in rats. For male animals, the time of exposure did not cover the full length of spermatogenesis and, therefore, a longer term study at higher doses would be needed to clarify the effects on testes observed in the 90‐day study. No maternal and developmental toxicity was observed. Considering the systemic availability of mogroside V, the effects observed in the rat subchronic study and following the principles of EFSA Guidance on food additives evaluation, data from chronic/carcinogenicity toxicity testing would have been warranted. Exposure to mogroside V was calculated based on the proposed use levels. The Panel concluded that toxicity database on Monk fruit extract is insufficient to conclude on the safety of the use of Monk fruit extract as a food additive.

Effects of metaxenia on the carbohydrate and mogroside content and related enzyme activities in Siraitia grosvenorii fruit

The fruits of Siraitia grosvenorii have been used as a natural sweetening agent for centuries and have also been reported to aid diabetic patients. Mogroside V is the primary sweet compound in S. grosvenorii fruit. In this study, we show that different pollen sources had a direct influence on the mogroside V content in S. grosvenorii fruit. The changes in the activities of carbohydrate metabolism-related enzymes during fruit development were examined, as well as the results of linear regression analysis of mogroside V and variables such as the carbohydrate content and activities of related enzymes. This indicated that sucrose metabolism was significantly correlated with mogroside V contents, and higher sucrose accumulation results in higher mogroside V levels. In addition, our results revealed an obvious effect of metaxenia on carbohydrate accumulation, sucrose and starch metabolism-related enzyme activities, which revealed the reason for the effect of metaxenia on the accumulation of mogroside V in S. grosvenorii fruit. These results suggest that the effects of metaxenia should be considered in future breeding programs.

Identification of a Novel Specific Cucurbitadienol Synthase Allele in Siraitia grosvenorii Correlates with High Catalytic Efficiency.

Mogrosides, the main bioactive compounds isolated from the fruits of Siraitia grosvenorii, are a group of cucurbitane-type triterpenoid glycosides that exhibit a wide range of notable biological activities and are commercially available worldwide as natural sweeteners. However, the extraction cost is high due to their relatively low contents in plants. Therefore, molecular breeding needs to be achieved when conventional plant breeding can hardly improve the quality so far. In this study, the levels of 21 active mogrosides and two precursors in 15 S. grosvenorii varieties were determined by HPLC-MS/MS and GC-MS, respectively. The results showed that the variations in mogroside V content may be caused by the accumulation of cucurbitadienol. Furthermore, a total of four wild-type cucurbitadienol synthase protein variants (50R573L, 50C573L, 50R573Q, and 50C573Q) based on two missense mutation single nucleotide polymorphism (SNP) sites were discovered. An in vitro enzyme reaction analysis indicated that 50R573L had the highest activity, with a specific activity of 10.24 nmol min−1 mg−1. In addition, a site-directed mutant, namely, 50K573L, showed a 33% enhancement of catalytic efficiency compared to wild-type 50R573L. Our findings identify a novel cucurbitadienol synthase allele correlates with high catalytic efficiency. These results are valuable for the molecular breeding of luohanguo.

The metabolism of a natural product mogroside V, in healthy and type 2 diabetic rats

Mogroside V, a natural compound isolated from the fruits of Siraitia grosvenorii (Swingle), is a promising candidate for anti-diabetic activity. The present study aims to develop a simple and practical strategy for comparing the in vivo metabolite profiling of mogroside V in healthy and type 2 diabetic (T2D) model rats. In this paper, a highly sensitive and rapid 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 and successfully applied to detect and identify the metabolites in plasma, urine, bile and feces samples of healthy and model rats administrated with mogroside V. The distribution of metabolites in plasma, bile, urine and feces of healthy and model rats had obvious differences. A total of 23 metabolites were observed in healthy rats while 26 metabolites were detected in model rats. The results indicated that dehydrogenation, deoxidation, oxidation and isomerization were the major metabolic transformations of mogroside V. Additionally, it was noticed that the peak areas of metabolites in T2D rat plasma samples were much larger than those of metabolites in healthy rat plasma sample, whereas in T2D rat urine samples they were remarkably smaller compared with healthy rat urine sample. These high blood concentrations of metabolites might be beneficial for the treatment of T2D. The results of this study are valuable and important in understanding the metabolic process and therapeutic mechanism of mogroside V.

Development and Validation of a Sensitive LC-MS-MS Method for Quantification of Mogrol in Rat Plasma and Application to Pharmacokinetic Study.

Mogrol, the aglycone of mogrosides, is a potential pharmacologically active ingredient isolated from the fruits of Siraitia grosvenorii. The aim of this study was to develop and validate an LC-MS-MS method for the quantification of mogrol in rat plasma. Protein precipitation extraction procedure using methanol/water (1:1, v/v) was employed to extract mogrol from rat plasma. Chromatographic separation was performed on a reverse-phase Agilent Zorbax XDB C18 column (50 mm × 2.1 mm, 3.5 μm) with gradient elution using a mobile phase containing methanol and water, both of which contained 0.1% formic acid at a flow rate of 0.50 mL/min. The analyte was monitored by tandem-mass spectrometry with positive electrospray ionization mode. The precursor/product transitions (m/z) in the positive ion mode were 459.3→423.3 and 386.2→122.3 for mogrol and internal standard, respectively. The method was validated over the concentration range of 10.0-10,000 ng/mL with a lower limit of quantification of 10.0 ng/mL in rat plasma. Validation experiments included tests for specificity, precision, accuracy, matrix effect, and stability under different storage and handling conditions. This method was successfully utilized to pharmacokinetic evaluation of mogrol after intravenous and oral administration of a single dose in rats at 2.0 and 5.0 mg/kg, respectively. The oral absolute bioavailability (F) of mogrol was estimated to be 10.3 ± 2.15% with an elimination half-life (t1/2) value of 2.41 ± 0.11 h.

Liquid chromatography with tandem mass spectrometry method for the simultaneous determination of multiple sweet mogrosides in the fruits of Siraitia grosvenorii and its marketed sweeteners.

A high-performance liquid chromatography with electrospray ionization tandem mass spectrometry method has been developed and validated for the simultaneous quantification of eight major sweet mogrosides in different batches of the fruits of Siraitia grosvenorii and its marketed sweeteners. The sample preparation procedure and chromatographic and mass spectrographic conditions were optimized. Chromatographic separation was achieved on a reversed-phase Poroshell 120 SB C18 column in 10.0 min with gradient elution with acetonitrile and water, both of which contained 0.1% formic acid. The multiple reaction monitoring scanning mode was employed for quantification in the negative ion mode. The developed method was validated with acceptable linearity (r2 = 0.9984-0.9998) over a wide concentration range, precision (relative standard deviations = 1.09-3.91%), stability (relative standard deviations = 1.21-3.01%), and recovery in the range of 91.22-106.58% (relative standard deviations ≤ 3.79%) under optimum conditions. The proposed method was demonstrated to be simple, rapid, specific, and reliable and was successfully applied for the quality control of the fruits of S. grosvenorii and its marketed sweeteners.

Cloning and expression of SgCYP450-4 from Siraitia grosvenorii

CYP450 plays an essential role in the development and growth of the fruits of Siraitia grosvenorii. However, little is known about the SgCYP450-4 gene in S. grosvenorii. Here, based on transcriptome data, a full-length cDNA sequence of SgCYP450-4 was cloned by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid-amplification of cDNA ends (RACE) strategies. SgCYP450-4 is 1677bp in length (GenBank accession No. AEM42985.1) and contains a complete open reading frame (ORF) of 1422bp. The deduced protein was composed of 473 amino acids, the molecular weight is 54.01kDa, the theoretical isoelectric point (PI) is 8.8, and the protein was predicted to possess cytochrome P450 domains. SgCYP450-4 gene was highly expressed in root, diploid fruit and fruit treated with hormone and pollination. At 10 days after treatment with pollination and hormones, the expression of SgCYP450-4 had the highest level and then decreased over time, which was consistent with the development of fruits of S. Grosvenorii. Hormonal treatment could significantly induce the expression of SgCYP450-4. These results provide a reference for regulation of fruit development and the use of parthenocarpy to generate seedless fruit, and provide a scientific basis for the production of growth regulator application agents.

Oxidation of Cucurbitadienol Catalyzed by CYP87D18 in the Biosynthesis of Mogrosides from Siraitia grosvenorii.

Mogrosides, the principally bioactive compounds extracted from the fruits of Siraitia grosvenorii, are a group of glycosylated cucurbitane-type tetracyclic triterpenoid saponins that exhibit a wide range of notable biological activities and are commercially available worldwide as natural sweeteners. The biosynthesis of mogrosides involves initial cyclization of 2,3-oxidosqualene to the triterpenoid skeleton of cucurbitadienol, followed by a series of oxidation reactions catalyzed by Cyt P450s (P450s) and then glycosylation reactions catalyzed by UDP glycosyltransferases (UGTs). We previously reported the identification of a cucurbitadienol synthase (SgCbQ) and a mogrol C-3 hydroxyl glycosyltransferase (UGT74AC1). However, molecular characterization of further transformation of cucurbitadienol to mogrol by P450s remains unavailable. In this study, we report the successful identification of a multifunctional P450 (CYP87D18) as being involved in C-11 oxidation of cucurbitadienol. In vitro enzymatic activity assays showed that CYP87D18 catalyzed the oxidation of cucurbitadienol at C-11 to produce 11-oxo cucurbitadienol and 11-hydroxy cucurbitadienol. Furthermore, 11-oxo-24,25-epoxy cucurbitadienol as well as 11-oxo cucurbitadienol and 11-hydroxy cucurbitadienol were produced when CYP87D18 was co-expressed with SgCbQ in genetic yeast, and their structures were confirmed by liquid chromatography-solid-phase extraction-nuclear magnetic resonance-mass spectrometry coupling (LC-SPE-NMR-MS). Taken together, these results suggest a role for CYP87D18 as a multifunctional cucurbitadienol oxidase in the mogrosides pathway.

The Gastrointestinal Tract Metabolism and Pharmacological Activities of Grosvenorine, a Major and Characteristic Flavonoid in the Fruits of Siraitia grosvenorii.

Grosvenorine is the major flavonoid compound of the fruits of Siraitia grosvenorii (Swingle) C. Jeffrey, a medical plant endemic to China. In the present study, for the first time, the grosvenorine metabolism in an in vitro simulated human gastrointestinal tract (including artificial gastric juice, artificial intestinal juice and intestinal flora), as well as its pharmacological activities (including anti-complement, antibacterial and antioxidant activities), was investigated. The results showed that grosvenorine was metabolized by human intestinal flora; its four metabolites were isolated by semi-preparative HPLC and identified by NMR as kaempferitrin, afzelin, α-rhamnoisorobin, and kaempferol. Further pharmacological evaluation showed that grosvenorine exhibited good antibacterial and antioxidant activities, with its metabolites possessing more potent activities. Although grosvenorine did not present obvious anticomplement activity, its metabolites showed interesting activities. This study revealed that intestinal bacteria play an important role in the gastrointestinal metabolism of grosvenorine and significantly affect its pharmacological activities.

Functional Characterization of Cucurbitadienol Synthase and Triterpene Glycosyltransferase Involved in Biosynthesis of Mogrosides from Siraitia grosvenorii.

Mogrosides, the major bioactive components isolated from the fruits of Siraitia grosvenorii, are a family of cucurbitane-type tetracyclic triterpenoid saponins that are used worldwide as high-potency sweeteners and possess a variety of notable pharmacological activities. Mogrosides are synthesized from 2,3-oxidosqualene via a series of reactions catalyzed by cucurbitadienol synthase (CbQ), Cyt P450s (P450s) and UDP glycosyltransferases (UGTs) in vivo. However, the relevant genes have not been characterized to date. In this study, we report successful identification of SgCbQ and UGT74AC1, which were previously predicted via RNA-sequencing (RNA-seq) and digital gene expression (DGE) profile analysis of the fruits of S. grosvenorii. SgCbQ was functionally characterized by expression in the lanosterol synthase-deficient yeast strain GIL77 and was found to accumulate cucurbitadienol as the sole product. UGT74AC1 was heterologously expressed in Escherichia coli as a His-tag protein and it showed specificity for mogrol by transfer of a glucose moiety to the C-3 hydroxyl to form mogroside IE by in vitro enzymatic activity assays. This study reports the identification of CbQ and glycosyltransferase from S. grosvenorii for the first time. The results also suggest that RNA-seq, combined with DGE profile analysis, is a promising approach for discovery of candidate genes involved in biosynthesis of triterpene saponins.

Effects of Siraitia grosvenorii Fruits Extracts on Physical Fatigue in Mice.

In this study, the effects of Siraitia grosvenorii fruits extracts (SGFE) on physical fatigue were investigated. One hundred and forty-four mice were randomly divided into four groups: control group, low-dose SGE-treated group, middle-dose SGE-treated group and high-dose SGFE-treated group. The animals of control group received an oral administration of physiological saline in a volume of 2.5 mL, and the animals of treated group received the same volume of SGFE (100, 200 and 400 mg/Kg bodyweight, once a day) for 28 days. After 28 days, anti-fatigue effects of SGFE were assessed 10 h after the last treatment by forced swimming test and some biochemical parameters related to fatigue, including blood lactic acid, serum urea nitrogen, liver glycogen and muscle glycogen were measured. The data showed that SGFE can extend the swimming time of the mice, as well as increasing the liver and muscle glycogen contents, but decrease the blood lactic acid and serum urea nitrogen levels. These results indicated that Siraitia grosvenorii fruits extracts had significant anti-fatigue effects on mice and these effects were dose-dependent.

Anti-obesity effects of mogrosides extracted from the fruits of Siraitia grosvenorii (Cucurbitaceae)

In this study, total mogrosides extracted from Siraitia grosvenorii as well as, mogrosides V and IV were tested for their effects on pancreatic lipase in vitro. The body weight and food intake, abdominal and epididymal fats weight, and hepatic triacylglycerol (TG) and total cholesterol (TC) contents were evaluated using male C57BL/6 mice fed with a high fat diet (HF) with or without different concentrations of total mogrosides for 11 weeks. Plasma TG was also evaluated after oral administration of lipid emulsions to mice. The results showed that total mogrosides as well as, mogrosides V and IV (600 μg/ml) demonstrated good inhibitory effects on pancreatic lipase activity. In vivo, total mogrosides suppressed the increase in body weight, abdominal and epididymal fats weight, TG and TC content in mice’s liver; TG content in plasma was reduced at 1 to 3 h after oral administration of the lipid emulsion plus total mogrosides compared to those in the lipid emulsion groups. In addition, mice fed with HF plus 2% total mogrosides for 3 days had higher TG level in the feces compared to the HF group, which might be due to decreased dietary fat absorption in the intestine caused by inhibition of pancreatic lipase activity. Key words: Mogroside, pancreatic lipase, high diet, obesity, mice.

Studies on chemical fingerprints of Siraitia grosvenorii fruits (Luo Han Guo) by HPLC

A novel, efficient, and accurate fingerprinting method using high performance liquid chromatography-photodiode array detection has been developed and optimized for the investigation and demonstration of the variance in chemical properties among Siraitia grosvenorii fruits from different origins. The effects of growth stages, cultivated varieties, collection locations, and fruit portions of the herb on chromatographic fingerprints were examined. Eleven compounds were identified on chromatograms by comparing the retention time and UV spectrum of each peak separately with those of external references. The results revealed that chromatographic fingerprints, combining similarity or hierarchical clustering analysis along with reference compounds, could efficiently identify and distinguish S. grosvenorii fruits from different sources, which provided helpful clues for studying the plants' secondary metabolites and benefitted quality control.

Cucurbitane Glycosides from the Fruits of Siraitia grosvenorii and Their Inhibitory Effects on Epstein−Barr Virus Activation

Six new cucurbitane glycosides, mogroside II B (2), 11-deoxymogroside III (4), 7-oxomogroside II E (5), 7-oxomogroside V (6), 11-oxomogroside II A1 (7), and 11-oxomogroside IV A (8), and two known but new naturally occurring cucurbitane glycosides, mogroside II A1 (1) and mogroside III A2 (3), were isolated from an ethanol extract of the fruits of Siraitia grosvenorii. Upon evaluation of compounds 1-8 for inhibitory effects against the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), all compounds exhibited inhibitory effects with IC50 values of 346-400 mol ratio/32 pmol TPA. In addition, compounds 1-8 showed weak inhibitory effects on activation of (+/-)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexemide (NOR 1), a nitric oxide (NO) donor.