Sephadex LH-20 Chromatography Research Articles

Quantification of multiple steroid hormones in serum and human breast cancer tissue by liquid chromatography-tandem mass spectrometry analysis

IntroductionSystemic and local steroid hormone levels may function as novel prognostic and predictive biomarkers in breast cancer patients. We aimed at developing a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous measurement of multiple, biologically pivotal steroid hormones in human serum and breast cancer tissue.MethodsThe quantitative method consisted of liquid-liquid extraction, Sephadex LH-20 chromatography for tissue extracts, and analysis of steroid hormones by liquid-chromatography-tandem mass spectrometry. We analyzed serum and tissue steroid hormone levels in 16 and 40 breast cancer patients, respectively, and assessed their correlations with clinical parameters.ResultsThe method included quantification of nine steroid hormones in serum [including cortisol, cortisone, corticosterone, estrone (E1), 17β-estradiol (E2), 17α-hydroxyprogesterone, androstenedione (A4), testosterone and progesterone) and six (including cortisone, corticosterone, E1, E2, A4, and testosterone) in cancer tissue. The lower limits of quantification were between 0.003–10 ng/ml for serum (250 µl) and 0.038–125 pg/mg for tissue (20 mg), respectively. Accuracy was between 98%-126%, intra-assay coefficient of variations (CV) was below 15%, and inter-assay CV were below 11%. The analytical recoveries for tissue were between 76%-110%. Tissue levels of E1 were positively correlated with tissue E2 levels (p<0.001), and with serum levels of E1, E2 and A4 (p<0.01). Tissue E2 levels were positively associated with serum E1 levels (p=0.02), but not with serum E2 levels (p=0.12). The levels of tissue E2 and ratios of E1 to A4 levels (an index for aromatase activity) were significantly higher in patients with larger tumors (p=0.03 and p=0.02, respectively).ConclusionsThe method was convenient and suitable for a specific and accurate profiling of clinically important steroid hormones in serum. However, the sensitivity of the profile method in steroid analysis in tissue samples is limited, but it can be used for the analysis of steroids in breast cancer tissues if the size of the sample or its steroid content is sufficient.

Detection of seco-macrotetrolides caused by regiospecific hydrolysis in Indonesian Streptomyces strains isolated at the karst area in Sulawesi Island

Among a total of 30 endophytic Streptomyces strains collected at the karst area in Sulawesi Island, Indonesia, four strains showed antimicrobial activity together with distinct purple-colored spot(s) on TLC after anisaldehyde staining and baking. Four endophytic strains AA004, AA010, AA034, and AA035 accumulated ionophore macrotetrolides (cyclic tetraesters) including nonactin, monactin, dinactin, trinactin, and tetranactin. Occasionally, strains AA034 and AA035 accumulated considerable amount of seco-macrotetrolides (ring-opened, linear macrotetrolides) including seco-dinactin, seco-monactin, and seco-trinactin, together with macrotetrolides as above mentioned. Time-course increase of seco-macrotetrolides indicates the subsequent hydrolysis of macrotetrolides. Seco-macrotetrolides in strain AA034 were separated from macrotetrolides and other metabolites through Sephadex LH20 and silica gel chromatographies, although seco-macrotetrolides contain inseparable five analogs. We here investigated the hydrolyzed positions in seco-macrotetrolides. ESI-CID-MS/MS analysis of seco-dinactin (m/z 805 as [M+Na]+) and its derivatives, methyl ester (m/z 819 as [M+Na]+) and O-acetyl methyl ester (m/z 861 as [M+Na]+), revealed that seco-dinactin obtained in strains AA034/AA035 is a single regioisomer with a cleavage at an ester bond between the alcohol of (−)-homononactate and the carboxylate of (+)-nonactate, suggesting the regioselective hydrolysis on the occurrence of seco-dinactin. Further ESI-CID-MS/MS analysis revealed that seco-monactin (m/z 791 as [M+Na]+) is also single regioisomer with the ester-bond cleavage between the alcohol of (−)-homononactate and the carboxylate of (+)-nonactate. In the case of seco-trinactin (m/z 819 as [M+Na]+), additional regioisomer with the ester-bond cleavage between the alcohol of (−)-homononactate and the carboxylate of (+)-homononactate was detected, together with the regioisomer with the ester-bond cleavage between the alcohol of (−)-homononactate and the carboxylate of (+)-nonactate. A mixture of seco-macrotetrolides exhibited no antimicrobial activity, indicating the importance of macrocyclic structure for antimicrobial activity.

Characterisation of pomegranate juice polyphenols identifies oenothein B as an endothelium-dependent vasodilator and regulator of endothelial function that enhances actions of oligomeric procyanidins

Abstract Background Cardiovascular disease mortality is reduced in individuals with high daily consumption of dietary polyphenols. Optimal daily intakes, choice of polyphenol, and mechanism of action have yet to be fully defined. Pomegranate juice (PJ) reduces blood pressure and improves endothelial function. These effects are attributed to the high levels of polyphenols, primarily ellagitannins. Purpose The aims of these investigations were (1) to identify PJ polyphenol(s) that altered endothelial function and could potentially lower blood pressure, and (2) to compare these endothelial actions to oligomeric procyanidins (OPC) purified from apple polyphenol extracts. Methods PJ polyphenols were purified by Sephadex LH-20 chromatography and RP-HPLC, and identified by LC-MS/MS and NMR. Fractions were screened for biological activity using cultured bovine aortic endothelial cells by measuring the degree of inhibition of endothelin-1 synthesis. Endothelial actions were further assessed by measuring changes in intracellular Ca2+ using FLIPR Ca2+-6 assay, qRT-PCR (EDN1, eNOS and KLF2 mRNAs), and NO synthesis (nitrite). Results Six PJ polyphenols were isolated. These were identified as punicalin, four punicalagin isomers, and oenothein B (OTB, a cyclic dimeric ellagitannin; LC-MS [M-H]-= 1567.1). At concentrations ≤5 µg/ml only OTB inhibited ET-1 synthesis (IC50 1.5 µg/ml). The identity of OTB was confirmed by NMR, and by comparison with OTB purified from Epilobium species. Further characterisation of the actions of OTB on endothelial cells showed pre-incubation with 1.25, 2.5 and 5 µg/ml OTB increased binding of biotinylated-OPC by 1.7, 2.3 and 3.8 fold. Subsequent studies of the interactions between OTB and OPC showed synergistic effects for decreases in ET-1 synthesis, EDN1 mRNA, and increases in KLF2 mRNA, eNOS mRNA and NO release. The effect of combining OTB (1 µg/ml) and OPC (1 µg/ml) lasted for over 24 h (relative to control: ET-1 -57%, EDN1 mRNA -63%, eNOS mRNA +69%, KLF2 mRNA +356%), when individually these polyphenols no longer had any significant effect. Intracellular Ca2+ responses also showed synergistic interactions, however the profile of [Ca2+] changes for OTB and OPC alone differed, suggesting separate signalling pathways initiating these endothelial responses. Endothelium-dependent vasodilator effects of OTB were confirmed on isolated mouse aorta (EC50 0.27 µg/ml). Conclusions These effects of OTB may underlie previously reported decreases in blood pressure and improvements in endothelial function after pomegranate juice consumption. Detailed understanding of the mechanism of action of OTB, and its interactions with OPC could lead to new therapeutic modalities for treating endothelial dysfunction in a broad spectrum of people at risk of cardiovascular disease.

Research on Secondary Metabolites From the Soft Coral-Associated Fungus Aspergillus sydowii SCSIO41203 and Their Bioactivities

Objective: As part of our ongoing search for bioactive secondary metabolites, the Beibu Gulf soft coral-derived fungus Aspergillus sydowii SCSIO41203 was investigated, which led to the isolation of 15 compounds. Methods: These compounds were purified by chromatographic methods, including normal phase silica gel column chromatography, octadecylsilyl column chromatography, Sephadex LH-20, and high-performance liquid chromatography. Their structures were elucidated by nuclear magnetic resonance, and mass spectrometry and compared their data with those related metabolites in the literature. Results: The structures of 1 to 15 were identified as expansol F (1), expansol C (2), expansol D (3), ( Z)-5-(hydroxymethyl)-2-(6′-methylhept-2′-en-2′-yl)phenol (4), ( E)-5-(hydroxymethyl)-2-(6′-methylhept-2′-en-2′-yl)phenol (5), sydonol (6), (-)-(7 R,10 S)-10-hydroxysydowic acid (7), (-)-(7 R,10 R)- iso-10-hydroxysydowic acid (8), sydowic acid (9), 1-hydroxyboivinianin A (10), (+)-sydonic acid (11), 3-hydroxydiorcinol (12), cordyol C (13), ( R)-mevalonolactone (14), and 4-methyl-5,6-dihydropyren-2-one (15). These isolated compounds were evaluated for antibacterial, cytotoxic, and enzyme-inhibitory activities. Among them, compounds 1 to 3 and 13 showed moderate acetylcholinesterase inhibitory activity, with IC50 values of 3.9, 33.8, 11.5, and 19.8 μM, respectively, with the positive control (tacrine) of 0.5 μM.

Chemical constituents from Callicarpa kwangtungensis and their hemostatic activities

This study aims to identify the chemical constituents from Callicarpa kwangtungensis and determine their activities. MCI, ODS, and Sephadex LH-20 chromatography and semi-preparative HPLC were employed to separate the chemical constituents. A total of 15 compounds were separated, and their structures were identified on the basis of spectroscopic analysis and comparison with the data in relevant literature. Specifically, the 15 compounds were 3-O-α-L-rhamnopyranosyl-6-O-β-D-apiofuranosyl-4-O-E-caffeoyl-D-glucopyranoside(1), 3,6-O-α-L-dirhamnopyranosyl-4-O-E-caffeoyl-D-glucopyranoside(2), β-OH-forsythoside B(3), β-OH-poliumoside(4),(+)-lyoniresinol-3α-O-β-D-apiofuranosyl-(1→2)-β-D-glucopyranoside(5),(+)-lyoniresinol-3α-O-β-D-glucopyranoside(6),(-)-lyoniresinol-3α-O-β-D-glucopyranoside(7), kelampayoside A(8), descaffeoylpoliumoside(9), acteoside(10), alyssonoside(11), poliumoside(12), isacteoside(13), acetyl forsythoside B(14), and forsythoside B(15). Compounds 1 and 2 were novel, and the NMR data of compounds 3 and 4 were reported here for the first time. Furthermore, the hemostatic activities of the extract and abundant ingredients(compounds 12 and 15) of C. kwangtungensis were determined with Yunnan Baiyao as the positive control and normal saline as the negative control. The extract and compounds 12 and 15 significantly shortened the tail tip bleeding time in mice.

Two new isoquinoline alkaloids from Corydalis hendersonii

Corydalis hendersonii(CH) is a Tibetan folk medicine with the functions of clearing heat, detoxifying, cooling blood, checking diarrhea, and lowering blood pressure. It is often used to treat high altitude polycythemia, vasculitis, peptic ulcer, and diarrhea. Nine compounds were separated from the ethanol extract of CH by silica gel, ODS, Sephadex LH-20 chromatography and semi-preparative HPLC. Their structures were identified as hendersine H(1),hendersine I(2), dehydrocheilanthifoline(3), protopine(4), izmirine(5), 6,7-methylenedioxy-1(2H)-isoquinolinone(6), icariside D_2(7), ethyl 4-(β-D-glucopyranosyloxy)-3-methoxybenzoate(8), 3-hydroxy-4-methoxybenzoic acid(9), respectively, by the spectroscopic data analysis and comparison with those in the literature. Among them, compounds 1 and 2 are new isoquinoline alkaloids, and compounds 7-9 are reported the first time for Corydalis. The hypoglycemic model of H9c2 cardiomyocytes and the inflammatory model of H9c2 cardiomyocytes induced by conditional supernatant were employed to determine the activities of the above compounds. The results showed that 20 μmol·L~(-1) compound 1 had a protective effect on H9c2 cardiomyocytes and 10 μmol·L~(-1) compounds 4 and 5 inhibited H9c2 cardiomyocyte inflammation induced by conditional supernatant.

Iristectorigenin C suppresses LPS-induced macrophages activation by regulating mPGES-1 expression and p38/JNK pathway

Ethnopharmacological relevanceNonsteroidal anti-inflammatory drugs (NSAIDs) have been used clinically to treat inflammatory diseases clinically. However, the adverse effects of NSAIDs cannot be ignored. Therefore, it is critical for us to find alternative anti-inflammatory drugs that can reduce adverse reactions to herbal medicine, such as Iris tectorum Maxim., which has therapeutic effects and can treat inflammatory diseases and liver-related diseases. Aim of the studyThis study aimed to isolate active compounds from I. tectorum and investigate their anti-inflammatory effects and action mechanisms. Materials and methodsFourteen compounds were isolated from I. tectorum using silica gel column chromatography, Sephadex LH-20, ODS and high performance liquid chromatography, and their structures were identified by examining physicochemical properties, ultraviolet spectroscopy, infrared spectroscopy, mass spectrometry, and nuclear magnetic resonance spectroscopy. Classical inflammatory cell models were established using lipopolysaccharide (LPS)-stimulated RAW264.7 cells and rat primary peritoneal macrophages to examine the effect of these compounds. To examine the action mechanisms, the nitric oxide (NO) levels were measured by Griess reagent and the levels of inflammatory cytokines in the supernatant were measured by ELISA; The expressions of major proteins in prostaglandin E2 (PGE2) synthesis and the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways were examined by Western blotting, and the mRNA expression levels were measured by quantitative real-time polymerase chain reaction; and the nuclear translocation of p65 was examined by high content imaging. Molecular docking was used to predict the binding of active compound to target protein. ResultsOur findings revealed that Iristectorigenin C (IT24) significantly inhibited the levels of NO and PGE2 without affecting cyclooxygenase (COX)-1/COX-2 expression in LPS-induced RAW264.7 cells and rat peritoneal macrophages. Furthermore, IT24 was shown to decrease the expression of microsomal prostaglandin synthetase-1 (mPGES-1) in LPS-induced rat peritoneal macrophages. IT24 did not suppress the phosphorylation and nuclear translocation of proteins in the NF-κB pathway, but it inhibited the phosphorylation of p38/JNK in LPS-stimulated RAW264.7 cells. Additionally, molecular docking analysis indicated that IT24 may directly bind to the mPGES-1 protein. ConclusionIT24 might inhibit mPGES-1 and the p38/JNK pathway to exert its anti-inflammatory effects and could be also developed as an inhibitor of mPGES-1 to prevent and treat mPGES-1-related diseases, such as inflammatory diseases, and holds promise for further research and drug development.

Isolation of Two New Phenolic Glycosides from Castanopsis chinensis Hance by Combined Multistep CC and HSCCC Separation and Evaluation of Their Antioxidant Activity.

The characteristics of high polarity and susceptibility to oxidation in phenolic glycosides increase the difficulty of their separation from natural products. In the present study, two new phenolic glycosides with similar structures were isolated from Castanopsis chinensis Hance using a combination of multistep CC and high-speed countercurrent chromatography. Preliminary separation of the target fractions was carried out by Sephadex LH-20 chromatography (100-0% EtOH in H2O). High-speed countercurrent chromatography with an optimized solvent system of N-Hexane/Ethyl acetate/Methanol/Water (1:6:3:4, v/v/v/v) with a satisfactory stationary phase retention and separation factor was used for further separation and purification of the phenolic glycosides. Consequently, two new phenolic glycoside compounds were obtained with purities of 93.0% and 95.7%. 1D-NMR and 2D-NMR spectroscopy, mass spectrometry, and optical rotation were employed to identify their structures, which were assigned as chinensin D and chinensin E. The antioxidant and α-glucosidase inhibitory activities of these two compounds were evaluated using a DPPH antioxidant assay and a α-glucosidase inhibitory assay. Both compounds showed good antioxidant activity with IC50 values of 54.5 ± 0.82 µg/mL and 52.5 ± 0.47 µg/mL. The α-glucosidase inhibitory activity of the compounds was poor. The successful isolation and structure identification of the two new compounds provides materials not only for a systematic isolation method of phenolic glycosides with similar structures, but also for the screening of antioxidants and enzyme inhibitors.

Two new prenylated 2-arylbenzofurans from roots of Artocarpus heterophyllus and their anti-respiratory burst activities

Two prenylated 2-arylbenzofurans were isolated from roots of Artocarpus heterophyllus, with a combination of various chromatographic approaches, including ODS, MCI, Sephadex LH-20, and semipreparative high performance liquid chromatography(HPLC). They were identified as 5-[6-hydroxy-4-methoxy-5,7-bis(3-methylbut-2-enyl)benzofuran-2-yl]-1,3-benzenediol(1) and 5-[2H,9H-2,2,9,9-tetramethyl-furo[2,3-f]pyrano[2,3-h][1]benzopyran-6-yl]-1,3-benzenediol(2) with spectroscopic methods, such as HR-ESI-MS, IR, 1D NMR, and 2D NMR, and named artoheterins B(1) and C(2), respectively. The anti-respiratory burst activities of the two compounds were evaluated with rat polymorphonuclear neutrophils(PMNs) stimulated by phorbol 12-myristate 13-acetate(PMA). The results showed that 1 and 2 exhibited significant inhibitory effect on respiratory burst of PMNs with IC_(50) values of 0.27 and 1.53 μmol·L~(-1), respectively.

Isolation and purification of 12 flavonoid glycosides from Ginkgo biloba extract using sephadex LH-20 and preparative high-performance liquid chromatography.

An efficient and rapid preparative method for the separation and purification of flavonoid glycosides from the Ginkgo biloba extract (GBE) was developed bysephadex LH-20 and preparative high-performance liquid chromatography (HPLC). 40g GBE of 24% flavonoids were loaded onto the sephadex LH-20 column and five fractions (1.15, 2.57, 1.32, 4.45, and 3.31g) at flavonoid content of 72.3, 54.2, 63.5, 51.2, and 59.2% were produced. Ultimately, 12 flavonoid glycosides that are at least purities of 97.7% were obtained from 100mg of each fraction by preparative HPLC. The fraction A, B, and Deach contained two flavonoids, yielded 35, 30, 23, 20, 25, and 25mg, respectively. The fraction C and E each contained three flavonoids, produced 20, 13, 15, 18, 15, and 20mg, respectively. The chemical structures of the purified compounds were identified by nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI/MS).

Two new phenylpropanoids from the leaves of Rauvolfia vomitoria

ObjectiveStudy on the non-alkaloid chemical constituents with novel structure and their biological activities from the w-butanol fraction of the leaves of Rauvolfia vomitoria. MethodsThe w-butanol fraction of R. vomitoria was separated by silica gel, ODS, and Sephadex LH-20 chromatography column, as well as semi-preparative HPLC to obtain five compounds. Their structures were identified by extensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR, and ECD analysis. All the isolated compounds were evaluated their AChE inhibitory activities by Ellman’s method with slight modification, their vasorelaxant activities against phenylephrine-induced contraction of rat mesenteric arteries, and their inhibitory activity of a-glucosidase employing pNPG as substrate. ResultsTwo new phenylpropanoids (1-2) along with three known compounds, methyl trans-3,4,5-trimethoxycinnamate (3), methyl cis-3,4,5-trimethoxycinnamate (4), and 3,4,5-trimethoxybenzoic acid methyl ester (5), were isolated from the leaves of R.vomitoria. The five isolated compounds did not show significant tested activity. ConclusionChemical investigation of the leaves of R. vomitoria led to the isolation and identification of two new phenylpropanoids (1–2), expanding the study of non-alkaloids in the genus of Rauvolfia and enriching the chemical diversity of this genus.

Application of Biotransformation-Guided Purification in Chinese Medicine: An Example to Produce Butin from Licorice

Natural compounds are considered treasures in biotechnology; however, in the past, the process of discovering bioactive compounds is time consuming, and the purification and validation of the biofunctions and biochemistry of compounds isolated from a medicinal herb are tedious tasks. In this study, we developed an economical process called biotransformation-guided purification (BGP), which we applied to analyze licorice, a traditional Chinese medicine widely used in many therapies. This medicinal herb contains various flavonoids and triterpenoids and, thus, is a suitable material used to assess the ability of BGP to identify and produce bioactive compounds. In the BGP process, the ethyl acetate extract of a commercial licorice medicine was partially purified into three fractions by Sephadex LH-20 chromatography, and Bacillus megaterium tyrosinase (BmTYR) was used to catalyze the biotransformation of the extract from each fraction. One of the products produced via BmTYR-driven biotransformation was purified from the biotransformation-positive extract using preparative C-18 high-performance liquid chromatography, and it was identified as butin (3′-hydroxyliquiritigenin) through nucleic magnetic resonance and mass spectral analyses. Butin was produced from liquiritigenin through BmTYR-catalyzed hydroxylation, with commercial liquiritigenin as the biotransformation precursor. The proposed alternative approach quickly identified and isolated the biotransformed butin from licorice. Moreover, butin demonstrated an antioxidant activity that is stronger by over 100-fold compared with that of its precursor (liquiritigenin). This study showed that the economical BGP process could quickly obtain and validate bioactive molecules from crude extracts of medicinal herbs.

Flavonoid and chromone-rich extract from Euscaphis Konishii Hayata leaf attenuated alcoholic liver injury in mice

Ethnopharmacological relevanceEuscaphis konishii Hayata is a traditional medicinal plant in China, and its leaves are usually used to make dishes for hepatic or gastrointestinal issues by Chinese She nationality. Pharmacological analysis showed that E. konishii leaves contain high levels of flavonoids and chromones with favorable anti-hepatoma effect. Aim of the studyThe extract from E. konishii leaves was detected to evaluate its chemical composition, and the alcoholic liver injury mice model was adopted to elucidate its hepatoprotective effects. Materials and methodsThe total leaf extract from E. konishii was separated by polyamide column to get the flavonoid and chromone-rich extract (FCE). Single compounds from FCE was purified by gel and Sephadex LH-20 chromatography and analyzed by nuclear magnetic resonance (NMR). The chemical component of FCE was confirmed and quantified by HPLC-MS. The OH·, O2-, DPPH and ABTS + free radical assays were adopted to estimate the antioxidant activity of FCE in vitro. The alcohol-fed model mice were established to assess the hepatoprotective capacity of FCE in vivo, through biochemical determination, histopathological analysis, mitochondrial function measurement, quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) detection and Western blot determination. Results8 flavonoids and 2 chromones were recognized in the FCEextract by both NMR and HPLC-MS. FCE represented strong free radicals scavenging activity in vitro. With oral administration, FCE (50, 100 and 200 mg/kg) dose-dependently decreased the serum levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) in alcohol-fed mice. FCE gradually reduced the malondialdehyde (MDA) content, increased the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the alcohol-treated liver tissues. FCE also alleviated the hepatic inflammation, inhibited the hepatocyte apoptosis and lessened the alcohol-induced histological alteration and lipid accumulation in the liver tissues. FCE administration inhibited the overexpression of endoplasmic reticulum (ER) chaperones signaling and unfolded protein response (UPR) pathways to defense the ER-induced apoptosis. Pretreatment with FCE also restored the mitochondrial membrane potentials andadenosine triphosphate (ATP) levels, which in turn suppressed the Cytochrome C release and mitochondria-induced apoptosis. ConclusionsFCE conferred great protection against alcoholic liver injury, which might be associated with its viability through suppressing reactive oxygen species (ROS) stress and hepatocyte apoptosis.

Hydrolyzable tannins from flowers of Punica granatum and their anti-diabetic activities

To investigate the active components against diabetes, the present study isolated eight hydrolyzable tannins from the ethyl acetate extract of Punica granatum flowers by MCI, reversed-phase chromatography(ODS), Sephadex LH-20 chromatography, and HPLC, and the structures were elucidated as 1-O-galloyl-6-O-feruloyl-β-D-glucose(1), 1,2,3,4,6-penta-O-gally-β-D-glucopyranose(2), punicafolin(3), corilagin(4), telimagrandin Ⅰ(5), 1,2-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-β-D-glucose(6), heterophylliin A(7), and eugeniin(8) on the basis of spectral data and literature records. Among them, compound 1 is a new compound, and compounds 5-8 were isolated from this species for the first time. All isolated compounds were tested for inhibitory activities against α-glucosidase and DPP-Ⅳ. The results indicated that compounds 2, 3, and 5-8 showed significant inhibitory activities against α-glucosidase, while compounds 1 and 4 exhibited moderate inhibitory activities. Compounds 5, 7, and 8 showed moderate inhibitory effects on DPP-Ⅳ. In addition, the type of enzyme inhibition of compound 5 was determined.

Two novel cephalotaxine-type alkaloids from Cephalotaxus sinensis

Silica gel, octadecyl-silica(ODS), Sephadex LH-20, and semi-preparative high performance liquid chromatography(HPLC) was performed to isolate nine cephalotaxine-type alkaloids from Cephalotaxus sinensis: 8-oxodeoxyharringtonine(1), 8-oxonordeoxyharringtonine(2), cephafortunine A(3), 8-oxocephalotaxine(4), deoxyharringtonine(5), acetylcephalotaxine(6), cephalotaxine(7), epicephalotaxine(8), and cephalotaxinone(9). Compounds 1 and 2 were identified for the first time and their structures were determined by high-resolution-electrospray ionization-mass spectrometry(HR-ESI-MS), nuclear magnetic resonance(NMR), and electronic circular dichroism(ECD). Compounds 1-3 and 5 significantly inhibited the transcription of nuclear factor kappa B(NF-κB), with the half-maximal inhibitory concentration(IC_(50)) of(3.91±0.70),(2.99±0.45),(7.84±0.51), and(1.46±0.17) μmol·L~(-1), respectively.

Proanthocyanidin Tetramers and Pentamers from Cinnamomum verum Bark and Their Dentin Biomodification Bioactivities.

To enable the further exploration of structure-activity relationships (SARs) of proanthocyanidins (PACs) with dentin biomodification abilities, Cinnamomum verum was selected for scaled-up purification of mixed A-/B-type, medium-size PAC oligomers. Sequential purification by centrifugal partition chromatography (CPC), Sephadex LH-20, and semiprep HPLC chromatography yielded four underivatized tetrameric (5-8) and two pentameric (9-10) PACs. Their unambiguous structural characterization involved extensive spectral and chemical degradation approaches to show that epicatechin units are connected by plant-specific combinations of doubly linked A- and singly linked B-type interflavanyl bonds. The biomechanical properties (via dynamic mechanical analysis) and physicochemical structure (via infrared spectroscopy) were assessed to evaluate the biomodification potency of PAC-treated collagen in a preclinical dentin model. This study revealed that (4→8) versus (4→6) bonds in PAC interflavan linkages have limited influence on biomechanical outcomes of dentin. By exhibiting a 25-fold increase in the complex modulus of treated dentin compared to control, aesculitannin E (5) was found to be the most potent PAC known to date for enhancing the mechanical properties of dentin in this preclinical model.

Steroids from Uncaria rhynchophylla

Thirteen steroids(1-13) were isolated from the non-alkaloid constituents of Uncaria rhynchophylla by column chromatography on silica gel, ODS, Sephadex LH-20, and preparative HPLC chromatography, and their structures were elucidated by analyses of the MS and NMR spectral data. All the compounds were isolated from the genus Uncaria for the first time, and 1 was a new compound. The ~1H-NMR and ~(13)C-NMR data of two compounds(12 and 13) in deuteron-chloroform were completely assigned. This study enriched the steroid constituents of U. rhynchophylla and provided scientific references for the elucidation of active constituents and further development and utilization of U. rhynchophylla.

New eudesmane sesquiterpenoids from Atractylodis Macrocephalae Rhizoma and their inhibitory activities against SREBPs

Three sesquiterpenoids were isolated and purified from the 95% ethanol extract of Atractylodis Macrocephalae Rhizoma by column chromatography on silica gel, Sephadex LH-20, ODS, and high-performance liquid chromatography(HPLC). Their chemical structures were identified on the basis of spectroscopic analysis and physiochemical properties as(7Z)-8β,13-diacetoxy-eudesma-4(15),7(11)-diene(1), 7-oxo-7,8-secoeudesma-4(15),11-dien-8-oic acid(2), and guai-10(14)-en-11-ol(3). Compounds 1 and 2 are new compounds and compound 3 was obtained from Compositae family for the first time. Compounds 1, 2, and 3 showed weak inhibitory activities against sterol regulatory element-binding proteins(SREBPs).

Condensed tannins from roots of Indigofera stachyodes

Eleven condensed tannins were isolated from the roots of Indigofera stachyodes by various column chromatography techniques including silica gel, octadecyl silica(ODS), Sephadex LH-20, and semi-preparative high performance liquid chromatography(HPLC). These compounds were identified on the basis of physicochemical properties, nuclear magnetic resonance(NMR) and mass spectrometry(MS) data as stachyotannin A(1), epicatechin-(2β→O→7,4β→8)-epiafzelechin-(4β→8)-catechin(2), cinnamtannin D1(3), cinnamtannin B1(4), epicatechin-(2β→O→7,4β→8)-epiafzelechin-(4α→8)-epicatechin(5), gambiriin C(6), proanthocyanidin A1(7), proanthocyanidin A2(8), aesculitannin B(9), proanthocyanidin A4(10), and procyanidin B5(11). Compound 1 is a new compound. Compounds 2-11 were isolated from Indigofera for the first time. Furthermore, compounds 1, 2, and 4-11 showed inhibitory effects on thrombin-induced ATP release in platelets.

Two new pyranonaphthoquinones from Mansoa alliacea

Mansoa alliacea,commonly known as garlic vine,is native to the tropical rain forests of South America and widely cultivated in South China. As a popular folk medicine with various biological activities,however,this plant remains to be fully elucidated in terms of its phytochemical constituents. In this study,two new pyranonaphthoquinones were isolated from the 95% ethanol extract of the leaves and twigs of M. alliacea by various chromatographic approaches including silica gel,octadecyl silica( ODS),Sephadex LH-20,and preparative high-performance liquid chromatography( PHPLC). Their structures were determined to be 8,9-dimethoxy-α-lapachone( 1) and 7-hydroxy-8,9-dimethoxy-α-lapachone( 2) by comprehensive spectroscopic analyses and therefore respectively named as mansonin A( 1) and mansonin B( 2).