Network pharmacology and experimental verification to explore the anti-inflammatory activities of triterpenoids from Siraitia grosvenorii.

Siraitia grosvenorii (Swingle) C. Jeffrey (SG), a Chinese medicinal plant, exhibits promising anti-inflammatory properties. Based on previous reports, aglycone and mogrosides bearing lesser glucosyl groups may contribute to the bioactivity of SG in vivo. However, research has rarely been conducted to compare their activities and analyse the structure-activity relationship. In this study, the anti-inflammatory potency of triterpenoids from SG and possible mechanisms of action based on network pharmacology were investigated. Furthermore, eighteen triterpenoids were chosen to assess their anti-inflammatory activities and structure-activity relationship in LPS-induced RAW 264.7 cells, among which 11-oxo-mogrol performed the best. Western blotting and molecular docking identified that 11-oxo-mogrol could regulate the PI3K/AKT signalling pathway. These findings provide valuable insights into the molecular mechanisms underlying the anti-inflammatory properties of triterpenoids from SG and support their application as potential therapeutic agents for inflammatory diseases.

Multi-functional Chitosan Polymeric Micelles for improving the oral bioavailability of Paclitaxel based on synergistic effect.

A novel multi-functional micelle delivery system was developed for enhancing the oral absorption of paclitaxel (PTX). The delivery carriers were constructed by modifying chitosan-stearic acid (CS-SA) micelles with L-carnitine (LC) and co-encapsulating quercetin (Que), and the PTX-loaded micelles were prepared by film-sonication dispersing technique. The as-prepared micelles showed homogeneous spherical shapes with a small particle size of 148.3 ± 1.7 nm, high drug loading of 7.05% and low critical micelle concentration (CMC) of 16.89 µg/ml. Compared to the in-house PTX formulation similar to the commercial injection Taxol™, the target PTX-loaded micelles had obvious sustained-release effects and exhibited an oral relative bioavailability of 168.08%. The cellular uptake studies of Caco-2 cells confirmed the micellar modification of LC and the co-loading of Que played important roles in promoting the absorption of drug loaded in micelles. The CYP3A4 enzyme test demonstrated the micelles had an inhibitory effect on the metabolic enzyme due to the presence of Que. These findings confirmed the potential of the multi-functional chitosan polymeric micelles based on synergistic effect as an effective oral delivery system.

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.

The Triterpenoids from Munronia pinnata and Their Anti-Proliferative Effects.

Six new tirucallane-type triterpenoids, named munropenes A-F (1-6), were extracted from the whole plants of Munronia pinnata using a water extraction method. Their chemical structures were determined based on detailed spectroscopic data. The relative configurations of the acyclic structures at C-17 of munropenes A-F (1-6) were established using carbon-proton spin-coupling constants (2,3JC,H) and inter-proton spin-coupling constants (3JH,H). Furthermore, the absolute configurations of munropenes A-F (1-6) were determined through high-performance liquid chromatography (HPLC), single-crystal X-ray diffraction, and electronic circular dichroism (ECD) analyses. The antiproliferative effects of munropenes A-F were evaluated in five tumor cell lines: HCT116, A549, HepG2, MCF7, and MDAMB. Munropenes A, B, D, and F (1, 2, 4, and 6) inhibited proliferation in the HCT116 cell line with IC50 values of 40.90, 19.13, 17.66, and 32.62 µM, respectively.

Identification and Isolation of α-Glucosidase Inhibitors from Siraitia grosvenorii Roots Using Bio-Affinity Ultrafiltration and Comprehensive Chromatography.

The discovery of bioactive compounds from medicinal plants has played a crucial role in drug discovery. In this study, a simple and efficient method utilizing affinity-based ultrafiltration (UF) coupled with high-performance liquid chromatography (HPLC) was developed for the rapid screening and targeted separation of α-glucosidase inhibitors from Siraitia grosvenorii roots. First, an active fraction of S. grosvenorii roots (SGR2) was prepared, and 17 potential α-glucosidase inhibitors were identified based on UF-HPLC analysis. Second, guided by UF-HPLC, a combination of MCI gel CHP-20P column chromatography, high-speed counter-current countercurrent chromatography, and preparative HPLC were conducted to isolate the compounds producing active peaks. Sixteen compounds were successfully isolated from SGR2, including two lignans and fourteen cucurbitane-type triterpenoids. The structures of the novel compounds (4, 6, 7, 8, 9, and 11) were elucidated using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry. Finally, the α-glucosidase inhibitory activities of the isolated compounds were verified via enzyme inhibition assays and molecular docking analysis, all of which were found to exhibit certain inhibitory activity. Compound 14 exhibited the strongest inhibitory activity, with an IC50 value of 430.13 ± 13.33 µM, which was superior to that of acarbose (1332.50 ± 58.53 µM). The relationships between the structures of the compounds and their inhibitory activities were also investigated. Molecular docking showed that the highly active inhibitors interacted with α-glucosidase through hydrogen bonds and hydrophobic interactions. Our results demonstrate the beneficial effects of S. grosvenorii roots and their constituents on α-glucosidase inhibition.

Iridoid-glycoside isolation and purification from Premna fulva leaves.

Premna fulva Craib, rich in iridoid glycosides, is widely used to treat periarthritis, osteoproliferation, pain, and other diseases. However, no studies have reported effective purification methods for obtaining iridoid glycosides as active materials. This paper describes an efficient strategy for separating iridoid glycosides from Premna fulva leaves using high-speed counter-current chromatography and preparative high-performance liquid chromatography. A two-phase solvent system, ethyl acetate/n-butanol/water (7.5:2.5:10, v/v), was selected for high-speed counter-current chromatography separation. The proposed method effectively separated and purified four iridoid glycosides and four lignans, including three new iridoid glycosides (4-6) and five known compounds (1-3, 7, 8), from Premna fulva leaves, indicating that high-speed counter-current chromatography combined with prep-HPLC can efficiently isolate catalpol derivatives from the genus Premna. Additionally, the in vitro anti-inflammatory activities of all isolated compounds were analyzed using lipopolysaccharide-stimulated RAW 264.7 cells, and the results indicated that six compounds (1 and 3-7) exhibited potential anti-inflammatory activities.

Chemodivergent Photocatalyzed Heterocyclization of Hydrazones and Isothiocyanates for the Selectivity Synthesis of 2-Amino-1,3,4-thiadiazoles and 1,2,4-Triazole-3-thiones.

A photocatalytic chemodivergent reaction for the selectivity formation of C-S and C-N bonds in a controlled manner was proposed. The reaction medium, either neutral or acidic, is critical to dictate the formation of 2-amino-1,3,4-thiadiazoles and 1,2,4-triazole-3-thiones from isothiocyanates and hydrazones. This is a practical protocol to achieve the chemoselectivity under mild and metal-free conditions.

Acylated iridoid glucoside and xanthones from Canscora lucidissima: Their structures and ferroptosis inhibitory activity.

Phytochemical study on the whole plants of a Gentianaceous medicinal plant, Canscora lucidissima, gave one new acylated iridoid glucoside, canscorin A (1), and two new xanthone glycosides (2 and 3) together with 17 known compounds including five xanthones, eight xanthone glycosides, two benzophenone glucosides, caffeic acid, and loganic acid. Canscorin A (1) was assigned as a loganic acid derivative having a hydroxyterephthalic acid moiety by spectroscopic analysis together with chemical evidence, while 2 and 3 were elucidated to be a rutinosylxanthone and a glucosylxanthone, respectively. The absolute configurations of the sugar moieties of 2 and 3 were determined by HPLC analysis. The isolated compounds were evaluated for their inhibitory activities against erastin-induced ferroptosis on human hepatoma Hep3B cells and LPS-stimulated IL-1ß production from murine microglial cells.

Lindenane-Type Sesquiterpene Dimers Mitigate Lipopolysaccharide-Induced Inflammation by Inhibiting Toll-Like Receptor Signaling.

Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns and trigger an inflammatory response via the myeloid differential factor 88 (MyD88)-dependent and toll-interleukin-1 receptor domain-containing adapter-inducing interferon-ß (TRIF)-dependent pathways. Lindenane type sesquiterpene dimers (LSDs) are characteristic metabolites of plants belonging to the genus Sarcandra (Chloranthaceae). The aim of this study was to evaluate the potential anti-inflammatory effects of the LSDs shizukaol D (1) and sarcandrolide E (2) on lipopolysaccharides (LPS)-stimulated RAW264.7 macrophages in vitro, and explore the underlying mechanisms. Both LSDs neutralized the LPS-induced morphological changes and production of nitric oxide (NO), as determined by CCK-8 assay and Griess assay, respectively. Furthermore, shizukaol D (1) and sarcandrolide E (2) downregulated interferon ß (IFNß), tumor necrosis factor α (TNFα) and interleukin-1ß (IL-1ß) mRNA levels as measured by reverse transcription polymerase chain reaction (RT-PCR), and inhibited the phosphorylation of nuclear factor kappa B p65 (p65), nuclear factor kappa-Bα (IκBα), Jun N-terminal kinase (JNK), extracellular regulated kinase (ERK), mitogen-activated protein kinase p38 (p38), MyD88, IL-1RI-associated protein kinase 1 (IRAK1), and transforming growth factor-ß-activated kinase 1 (TAK1) proteins in the Western blotting assay. In conclusion, LSDs can alleviate the inflammatory response by inhibiting the TLR/MyD88 signalling pathway.

GUESS - A simple approach to accelerate optimization countercurrent separation.

The generally useful estimate of solvent systems (GUESS) method, which is based on thin layer chromatography, is a simple and practical method for selecting solvent systems for countercurrent chromatography (CCC). However, it is rarely used for complex samples derived from natural products. In this study, GUESS was used for CCC solvent system selection and polarity-adjusted CCC separations of several fractions, which were obtained from a silica gel column containing complex compositions with a broad polarity from Salvia bowleyana Dunn. The GUESS method was performed on five fractions based on solvent systems in the n-hexane-ethyl acetate-methanol-water (HEMWat) family. Based on the GUESS results, the optimal solvent systems were selected for CCC separation. Twelve diterpenoids were obtained from the five silica gel column fractions of S. bowleyana Dunn using elution-extrusion countercurrent chromatography (EECCC). These demonstrate that GUESS guidance and the polarity adjustment of the solvent system accelerate the optimization of CCC separation conditions and simplify the process of accommodating a broad polarity of components in complicated mixture fractions. We therefore confirmed the feasibility and advantage of the GUESS method for complex natural chemical component separations.

The generally useful estimate of solvent systems method facilitates off-line two-dimensional countercurrent chromatography for isolating compositions from Siraitia grosvenorii roots.

Solvent system selection is a crucial and the most time-consuming step for successful countercurrent chromatography separation. A thin-layer chromatography-based generally useful estimate of solvent systems method has been developed to simplify the solvent system selection. We herein utilized the method to select a solvent system for off-line two-dimensional countercurrent chromatography to separate chemical compositions from a complex fraction of the Siraitia grosvenorii root extract. The first-dimensional countercurrent separation using chloroform/methanol/water (10:5.5:4.5, v/v/v) yielded four compounds with high purity and three mixture fractions (Fr I, III, and VII). The second-dimensional countercurrent separation conducted on Fr I, III, and VII using the hexane/ethyl acetate/methanol/water (4:6:6:4, 3:7:3:7, v/v/v) and chloroform/methanol/water (10:9:6, v/v/v) solvent systems, respectively, produced another four compounds. Four triterpenoids and four lignans were finally isolated, including two novel compounds. Hence, the generally useful estimate of solvent systems method is a feasible and efficient approach for selecting an applicable solvent system for separating complex samples. In addition, the off-line two-dimensional countercurrent chromatography method can improve both the peak resolution and the capacity of countercurrent chromatography.

Design and synthesis of mogrol derivatives modified on a ring with anti-inflammatory and anti-proliferative activities.

A class of novel mogrol derivatives modified on A ring were synthesized. The screening result showed that indole-fused derivatives exhibited lower toxicity and better anti-inflammatory activity in LPS-induced RAW 264.7 cells model than mogrol and other compounds. Derivative B8 exerted superior inhibitory result of NO production (IC50 = 5.05 µM) and inhibitory ability of TNF-α and IL-6 secretion to mogrol through iNOS/NF-κB pathway. Besides, the CCK8 assay was performed to evaluate their anti-proliferative activity against non-small cell lung cancer including A549, NCI-H460, H1299 and H1975 cells. Compared with mogrol, compound B8 showed moderate anti-proliferative activities against A549 and H1975 cells, while derivatives bearing α, ß-unsaturated ketone scaffold displayed broad-spectrum growth inhibition against four cell lines. Among them, compound A9 showed 12-fold higher activity than mogrol against H1299 and H1975 cells. The suppressive effect on expression level of p-p65 might account for the compound A9-induced growth inhibition and cell cycle arrest at G1 phase.

[Preparation of cucurbitacin compounds in Siraitia grosvenorii roots by high speed countercurrent chromatography].

Siraitia grosvenorii (Swingle) C. Jeffrey, belonging to the family Cucurbitaceae, is a natural sweetener. The roots of this plant are used in folk medicine for the treatment of rheumatoid arthritis. Cucurbitacins play an important role in the resistance of this plant to insects and adversity, and have anti-inflammatory, anti-tumor, and other biological activities. They usually exist as a variety of similar structures in Cucurbitaceae plants. Separation of a large amount of high-purity monomer compounds by the conventional separation method based on column chromatography is difficult, which limits the research and application of their activities. Therefore, we chose a new method for this separation. High-speed countercurrent chromatography (HSCCC) is a liquid-liquid chromatographic technique characterized by high recovery and reproducibility, and is considered a very effective method for the separation of natural compounds present in various plant extracts. An appropriate solvent system is the key for efficient separation, but its selection is tedious, which hampers the wider implementation of HSCCC in chemical research involving preparative separations. In this study, based on the general estimation strategy by using the TLC solvent system (GUESS), the corresponding relationship between the partition distribution coefficient (K value) and the TLC retention factor (Rf value) of the compounds was established by the partition experiment. The Rf value and separation coefficient α were calculated using the water-saturated organic phase as the expansion agent, which could minimize the number of countercurrent separation experiments required in solvent system selection. In this study, HSCCC was used to establish an efficient method for the extraction of cucurbitacins from the root extract of Siraitia grosvenorii. A fraction rich in cucurbitacins was obtained from the ethanol extract of Siraitia grosvenorii roots after separation by column chromatography on HPD-100, MCI, and C18 columns. Six types of solvent systems with different compositions were investigated using the GUESS method. The results showed that employing the solvent system of n-hexane-ethyl acetate-methanol-water (3∶7∶3∶7, v/v/v/v) to partition the cucurbitacin fraction could remove a large number of impurities. The components retained in the upper phase in the partition experiment were subsequently purified by HSCCC. The favorable solvent system for HSCCC was n-hexane-ethyl acetate-methanol-water (4∶6∶5∶5, v/v/v/v), while the upper and lower phases were selected as the stationary and mobile phases, respectively, with a flow rate of 2.0 mL/min, a rotation speed of 860 r/min, and an injected sample weight of 280 mg. Five cucurbitacin compounds were obtained by one-time separation. The weights of the five compounds were 14.73, 8.82, 30.74, 5.03, and 3.81 mg. The purities of these compounds were 97.0%, 95.4%, 96.3%, 91.6%, and 95.3%, respectively. Their structures were identified as cucurbitacin Q1, 23,24-dihydrocucurbitacin F-25-acetate, cucurbitacin B, 23,24-dihydrocucurbitacin B, and dihydroisocucurbitacin B-25-acetate by1H-NMR and 13C-NMR spectroscopies, along with comparison with the literature. This study demonstrated how GUESS guidance accelerates the selection of HSCCC solvent systems, simplifies the workflow, and it provides an efficient preparative method for the separation of chemical constituents from the Siraitia grosvenorii roots, which can also be used as a new method for the large-scale preparation of cucurbitacin compounds.

Preparative isolation of diterpenoids from Salvia bowleyana Dunn roots by high-speed countercurrent chromatography combined with high-performance liquid chromatography.

The root of Salvia bowleyana Dunn (Lamiaceae) is used as a traditional Chinese medicine that has multiple therapeutic effects. In this study, an efficient strategy was developed to separate diterpenoid compounds, which are the main active ingredients in Salvia bowleyana Dunn roots, from complex crude extracts by high-speed countercurrent chromatography combined with preparative high-performance liquid chromatography. A two-phase solvent system comprising n-hexane-ethyl acetate-methanol-water (7:3:7:3, v/v/v/v) was selected for high-speed countercurrent chromatographic separation. Three major diterpenoids, 6α-hydroxysugiol (7), sugiol (8), and 6, 12-dihydroxyabieta-5,8,11,13-tetraen-7-one (9) were obtained at purities of 98.9, 95.4, and 96.2%, respectively, and minor diterpenoids were enriched via one-step separation. The enriched minor diterpenoids were further purified by continuous preparative high-performance liquid chromatography to yield two new norabietanoids (1, 6) and four known compounds (2-5). The structures of these new compounds were determined using NMR spectroscopy, high-resolution electrospray ionization mass spectrometry, and electronic circular dichroism spectroscopy. The results suggest that high-speed countercurrent chromatography combined with preparative high-performance liquid chromatography efficiently isolates diterpenoids, including minor components, from complex natural products.

Rhodomollosides A and B, glycosides of methyl everninate from the aerial parts of Rhododendron molle.

Two new glycosides of methyl everninate, rhodomollosides A (1) and B (2), were isolated from the aerial parts of a medicinal plant Rhododendron molle. The structures of 1 and 2 were elucidated on the basis of detailed spectroscopic analyses as well as HPLC analyses for thiazolidine derivatives of their sugar moieties. The sugar moiety of rhodomolloside A (1) was elucidated to be a rare monosaccharide, D-allose, while rhodomolloside B (2) was assigned as a D-glucoside of methyl everninate. Furthermore, they were evaluated for their cytotoxicity against RAW264.7 cells, and for their inhibitory effects with a lipopolysaccharide (LPS)-stimulated murine macrophages RAW 264.7 cells model.

Vicenin 3 ameliorates ECM degradation by regulating the MAPK pathway in SW1353 chondrocytes.

Aberrant destruction of the articular extracellular matrix (ECM) has been considered to be one of the pathological features of osteoarthritis (OA) which results in chondrocyte changes and articular cartilage degeneration. The MAPK signaling pathway serves a key role by releasing cartilage-degrading enzymes from OA chondrocytes. However, the use of MAPK inhibitors for OA is hindered by their potential long-term toxicity. Vicenin 3 is one of the major components of the Jian-Gu injection which is effective in the clinical treatment of OA. However, its potential impact on OA remain poorly understood. Therefore, the present study aimed to assess the effects of vicenin 3 on interleukin (IL)-1ß-treated SW1353 chondrocytes, which mimic the microenvironment of OA. These chondrocytes were pretreated with vicenin 3 (0, 5 and 20 µM) for 1 h and subsequently stimulated with IL-1ß (10 ng/ml) for 24 h. Nitric oxide (NO) production was measured using the Griess reaction, whereas the production of prostaglandin E2 (PGE2), matrix metalloproteinases (MMPs), A disintegrin-like and metalloproteinase with thrombospondin motifs (ADAMTSs), collagen type II and aggrecan were measured using ELISA. The mRNA expression of MMPs and ADAMTSs were measured using reverse transcription-quantitative PCR. The protein expression levels of MAPK were measured using western blotting. Vicenin 3 was found to significantly inhibit IL-1ß-induced production of NO and PGE. Increments in the expression levels of MMP-1, MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5 induced by IL-1ß, in addition to the IL-1ß-induced degradation of collagen type II and aggrecan, were all reversed by vicenin 3 treatment. Furthermore, vicenin 3 suppressed IL-1ß-stimulated MAPK activation, an effect that was similar to that exerted by SB203580, a well-known p38 MAPK inhibitor. In conclusion, vicenin 3 may confer therapeutic potential similar to that of the p38 MAPK inhibitor for the treatment of OA.

Hypoglycemic effects of esculeoside A are mediated via activation of AMPK and upregulation of IRS-1.

BACKGROUND: Tomato fruit (Lycopersicon esculentum Mill.) has been suggested to be useful for the prevention of diabetes. Esculeoside A is the main saponin compounds in tomatoes. This study investigated the hypoglycemic effects and the underlying mechanism of esculeoside A in C57BLKS/Leprdb (db/db) mice. METHODS: Wild-type C57BLKS (db/dm) mice were used in the db/dm mouse group and db/db mice were randomly divided into 2 groups: untreated and treated db/db mouse groups. Esculeoside A (100 mg/kg) was administered by gavage for 56 days to the treated db/db mouse group. Distilled water was administered to the db/dm mouse group and the untreated db/db mouse group. The blood and liver biochemical parameters and the expression of liver insulin signaling-related proteins were examined. RESULTS: The results showed that esculeoside A reduced the fasting blood glucose (FBG) levels and improved the glucose tolerance. Further investigation revealed that hepatic protein expressions of total AMP-activated protein kinase (T-AMPK), phosphorylated AMP-activated protein kinase (p-AMPK), insulin receptor substrate-1 (IRS-1), and glucokinase (GCK) were significantly upregulated after esculeoside A treatment. In contrast, the hepatic protein expression of phosphoenolpyruvate carboxykinase (PEPCK) was significantly downregulated by esculeoside A treatment. CONCLUSION: These findings suggested that esculeoside A has a potential of alleviating the metabolic abnormalities in db/db mice via regulation of AMPK/IRS-1 pathway. Our findings supported a possible application of esculeoside A as a functional supplement for diabetes treatment.

Preparation of flavone di-C-glycoside isomers from Jian-Gu injection (Premna fulva Craib.) using recycling counter-current chromatography.

Jian-Gu Injection (JGI, Premna fulva Craib) has been demonstrated to be effective in the clinical treatment of bone hyperplasia. However, an effective purification method of the JGI flavone C-glycosides as reference materials is not available. The present work developed a recycling counter-current chromatography approach to prepare these materials in high quality. An optimized biphasic solvent system composed of ethyl acetate/n-butanol/water (1:9:10, v/v/v) was employed to purify the five congeneric flavone C-glycosides, identified as apigenin 6,8-di-C-ß-d-glucopyranoside (vicenin 2), apigenin 6-C-ß-d-xylopyranosyl-8-C-ß-d-glucopyranoside (vicenin 1), apigenin 6-C-ß-d-xylopyranosyl-8-C-ß-d-galactopyranoside, apigenin 6-C-ß-d-glucopyranosyl-8-C-ß-d-xylopyranoside (vicenin 3), and apigenin 6-C-ß-d-galactopyranosyl-8-C-ß-d-xylopyranoside, by means of UHPLC-PDA-ESI-IT-ToF-MSn and NMR spectroscopy.

Phenolic Compounds from the Leaves of Castanopsis fargesii.

In the course of a phytochemical and chemotaxonomical investigation of Castanopsis species (Fagaceae), three new phenolic compounds, (3R,1'S)-[1'-(6″-O-galloyl-ß-d-gluco-pyranosyl)oxyethyl]-3-hydroxy-dihydrofuran-2(3H)-one (1), (2R,3S)-2-[2'-(galloyl)oxyethyl]-dihydroxybutanoic acid (2), and (3S,4S)-3-hydroxymethyl-3,4-dihydro-5,6,7-trihydroxy-4-(4'-hydroxy-3'-methoxyphenyl)-1H-[2]-benzopyran-1-one (3) were isolated from the fresh leaves of Castanopsis fargesii. In addition, a known phenolic glycoside, gentisic acid 5-O-α-l-rhamnopyranosyl-(1→2)-ß-d-glucopyranoside (4) was also isolated and identified. Their structures were elucidated by means of spectroscopic methods including one- and two-dimensional NMR techniques.

Metabolites of Siamenoside I and Their Distributions in Rats.

Siamenoside I is the sweetest mogroside that has several kinds of bioactivities, and it is also a constituent of Siraitiae Fructus, a fruit and herb in China. Hitherto the metabolism of siamenoside I in human or animals remains unclear. To reveal its metabolic pathways, a high-performance liquid chromatography-electrospray ionization-ion trap-time of flight-multistage mass spectrometry (HPLC-ESI-IT-TOF-MS(n)) method was used to profile and identify its metabolites in rats. Altogether, 86 new metabolites were identified or tentatively identified, and 23 of them were also new metabolites of mogrosides. In rats, siamenoside I was found to undergo deglycosylation, hydroxylation, dehydrogenation, deoxygenation, isomerization, and glycosylation reactions. Among them, deoxygenation, pentahydroxylation, and didehydrogenation were novel metabolic reactions of mogrosides. The distributions of siamenoside I and its 86 metabolites in rat organs were firstly reported, and they were mainly distributed to intestine, stomach, kidney, and brain. The most widely distributed metabolite was mogroside IIIE. In addition, eight metabolites were bioactive according to literature. These findings would help to understand the metabolism and effective forms of siamenoside I and other mogrosides in vivo.