Lipid constituents of Trifolium resupinatum var. microcephalum

The two new compounds (3-methyl-1-nonene-3-ol and 2',3'-dihydroxy propyl pentadecanoate) and four known compounds were isolated from Trifolium resupinatum L. var. microcephalum Zoh. (Leguminosae). All the compounds were reported for the first time from this plant. The stuructures of the isolates were determined by 1D, 2D NMR techniques and MS spectroscopy.     

Two new pyrrolizidine alkaloids from Senecio nemorensis

Two new compounds, including petasinoside A and chloridate-[N-chloromethyl-hectorine], were isolated from Senecio nemorensis. The structures of these compounds were elucidated by spectroscopic methods including 1D and 2D NMR experiments.     

A new phenolic glycoside from the stems of Hydnocarpus hainanensis

A new phenolic glycoside (1) was isolated from the stems of Hydnocarpus hainanensis, along with 11 known compounds. The structures of all compounds were deduced using 1D, 2D NMR spectroscopic methods. The anti-oxidation activities of several compounds were also evaluated.     

Complete 1H and 13C data assignments of two new guaianolides isolated from Ainsliaea fragrans

Two new guaianolides, 8alpha-hydroxy-11alpha,13-dihydroglucozaluzanin C and 11alpha,13-dihydroglucozaluzanin C, were isolated from Ainsliaea fragrans, along with two known guaianolides, 8alpha-hydroxy-11alpha,13-dihydrozaluzanin C and glucozaluzanin C. The structures of the new compounds were unambiguously established by HR-ESI-MS, one-dimensional (1D) (DEPT), two-dimensional (2D) ((1)H-(1)H COSY, HSQC, HMBC, ROESY) NMR experiments and by comparison with structurally related compounds. The known compounds were identified by comparison of spectral data with published references. Some NMR data of the known compounds were reported for the first time.     

Spicachlorantins G-J, new lindenane sesquiterpenoid dimers from the roots of Chloranthus spicatus

Four new lindenane sesquiterpenoid dimers, spicachlorantins G-J (1-4), were isolated from the roots of Chloranthus spicatus together with seven known compounds, including chloramultilide A, shizukaol B, shizukaol D, shizukaol F, shizukaol P, chlorahololide D, and cycloshizukaol A. The planar structures of the new compounds were established by 1D-, 2D-NMR, and MS analyses. The absolute configurations of these compounds were determined by analyzing rotating Overhauser enhancement and exchange spectroscopy (ROESY) and circular dichroism (CD) spectra.     

Three new flavans in dragon's blood from Daemonorops draco

Three new flavans were isolated from chloroform extracts of dragon's blood from Daemonorops draco, together with eight known compounds. The structures of the new flavans were determined by 1D and 2D NMR spectroscopic analysis. These compounds are the first examples of 2-methoxyflavans from D. draco and regarded as derivatives of biogenetic intermediates from flavans to chalcones, which are characteristic of the dragon's blood.     

Purification and preparation of compounds from an extract of Scutellaria barbata D. Don using preparative parallel high performance liquid chromatography

Preparative parallel high performance liquid chromatography combined with solvent partition and other pretreatments were adopted to separate and purify compounds from an extract of Scutellaria barbata D. Don. Mass-triggered fraction collection allowed the rapid and precise isolation of target compounds. Twelve compounds were isolated from the extract of S. barbata D. Don, their purity in area percent was determined by HPLC analysis, and the structures of seven compounds were further identified with HPLC/ESI-MS, (1)H NMR, and( 13)C NMR, among which 4-(3,4-dihydroxy-phenyl)-but-3-en-2-one, acacetin-7-diglucuronide, and luteolin-7-diglucuronide were the first to be identified from this plant. The results demonstrated that multi-channel parallel preparative HPLC/UV/MS is an efficient method for isolation and purification of compounds from natural products.     

Three New Phenol Compounds from Iris dichotoma Pall.

Three new phenolic compounds, irisdichototins D, E, and F ( 1 – 3 , resp.) were isolated from the stems of Iris dichotoma. The structures of the new compounds were elucidated by spectroscopic analyses, including 2D‐NMR techniques.     

Astolides A and B,antifungal and cytotoxic naphthoquinone-derived polyol macrolactones from Streptomyces hygroscopicus

Two new natural compounds, astolides A,B, were isolated from Streptomyces hygroscopicus collected from the alkaline soil obtained from Saratov region, Russia. The structures were elucidated by interpretation of UV spectroscopic, MS, 1D and 2D NMR data. The relative configurations were determined by analysis of NOESY/ROESY spectra and coupling constants. The isolated compounds were evaluated for their inhibitory activity against bacteria, fungi and yeasts and showed pronounced antifungal activity. Both compounds are noticeably cytotoxic, being active against doxorubicin-resistant human leukemia cell line.     

1H and 13C NMR assignments for two oxaphenalenones bacillosporin C and D from the mangrove endophytic fungus SBE-14

The complete (1)H and (13)C NMR assignments are reported for the novel natural product Bacillosporin D together with the known compound Bacillosporin C. These compounds containing seven rings were isolated from the mangrove endophytic fungus SBE-14 from the South China Sea. 1D and 2D NMR experiments, including COSY, HMQC and HMBC were used to the determination of the structures and NMR assignments. It is proposed that 1 was biogenetically produced by transforming 2. Transforming a lactone to an anhydride is unusual in nature.     

Enrichment of ligands for the serotonin receptor using the Shape Signatures approach

Shape Signatures, a new 3-dimensional molecular comparison method, has been adapted to rank ligands of the serotonin receptors. A set of 825 agonists and 400 antagonists together with approximately 10,000 randomly chosen compounds from the NCI database were used in this study. Both 1D and 2D Shape Signature databases were created, and enrichment studies were carried out. Results from these studies reveal that the 1D Shape Signature approach is highly efficient in separating agonists from a mixture of molecules which includes compounds randomly selected from the NCI database taken as inactives. It is also equally effective at separating agonists and antagonists from a pool of active ligands for the serotonin receptor. Parallel enrichment studies using 2D shape signatures showed high selectivity with more restricted coverage due to the high specificity of 2D signatures. The influence of conformational variation of the shape signature on enrichment was explored by docking a subset of ligands into the crystal structure of serotonin N-acetyltransferase. Enrichment studies on the resulting "docked" conformations produced only slightly improved results compared with the CORINA-generated conformations.     

Bioactive Trichothecenes Produced by the Myrothecium sp. QB‐1

Three new simple trichothecenes, 15‐acetyltrichoverrol B ( 3 ), 13′‐acetyltrichoverrin B ( 5 ), and 6′‐dehydroxytrichoverrin B ( 6 ), along with five known trichothecenes trichodermadienediol B ( 1 ), trichoverrol B ( 2 ), trichoverrin B ( 4 ), and roridins A ( 7 ) and D ( 8 ), have been isolated from the liquid culture of Myrothecium roridum (strain no. QB‐1). The structures of the new compounds were established by comprehensive analysis of 1D‐ and 2D‐NMR data. All the compounds were evaluated for antifungal activity, only compounds 7 and 8 showed significant antifungal activity against the tested fungi (MIC ranged from 10 to 5 μg/ml).     

Employing ultra high pressure liquid chromatography as the second dimension in a comprehensive two-dimensional system for analysis of Stevia rebaudiana extracts

Stevia rebaudiana extracts and plant materials are increasingly used as natural sweeteners. Polyphenolic and stevioside compounds contained in S. rebaudiana extracts were separated by comprehensive LC. A polyamine column operated in normal phase mode was used for the first dimension separation (D1), and a UHPLC C18 column operated in reversed phase mode was used for the second dimension separation (D2). The sub-2 μm column (2.1 mm × 30 mm, maintained at 70°C) and the UHPLC pump employed for D2 elution allowed a separation/cycle time of 20 s, with a backpressure oscillating between 805 and 922 bar at 3.4 mL/min. The reduced D2 cycle time allowed 3-12 D2 samplings for each peak eluted by D1. Polyphenolic and stevioside compounds were identified by combining the information coming from the position of the compounds in the 2D plot and UV spectra with that of reference materials.     

New Highly Oxidized Formamidobisabolene‐Derived Sesquiterpenes from a Hainan Sponge Axinyssa variabilis

Two new highly oxidized formamidobisabolene sesquiterpenes ( 1 and 2 ), together with seven known related analogues ( 3 – 9 ), were isolated from a Hainan sponge Axinyssa variabilis. Their structures were determined by extensive 1D‐ and 2D‐NMR and MS spectra analyses, and by comparison of their spectroscopic data with those of the related model compounds. The plausible biosynthetic relationship between compounds 1 – 9 has also been described.     

Taumycins A and B, two bioactive lipodepsipeptides from the Madagascar sponge Fascaplysinopsis sp

Two closely related lipodepsipeptides, taumycins A and B (1 and 2) have been isolated from the Madagascar sponge Fascaplysinopsis sp. The two compounds have the same 12-membered oxodepsipeptide ring system in common. Both were toxic to brine shrimp larvae, and taumycin A (1 microM), but not taumycin B, inhibited growth of the human UT-7 leukemic cell line. The structure of the two compounds, likely to be derived from microorganisms, was established by MS and 1D and 2D NMR data.     

Iridoid Glycosides from Hedyotis corymbosa

Three new iridoid glycosides, hedycorysides A–C ( 1 – 3 , resp.), were isolated from the whole plant of Hedyotis corymbosa (Linn .) Lam ., along with four known compounds. Their structures were elucidated by extensive 1D‐ and 2D‐NMR analysis, as well as by HR‐ESI‐MS experiments. The three new compounds are the first benzoylated geniposide derivatives from Hedyotis.     

锦灯笼果实的化学成分研究

从锦灯笼中分离得到5个甾体类化合物,分别鉴定为酸浆素A(1,alkekengilin A)、酸浆素B(2,alkekengilin B)、酸浆苦素D(3,physalin D)、酸浆苦素P(4,physalin P)、4,7-二去氢新酸浆苦素B(5,4,7-didehydro-neophysalin B).其中酸浆素A(1,alkekengilin A)和酸浆素B(2,alkekengilin B)为新的天然产物.运用现代波谱技术对上述化合物的结构进行了确证.     

Isolation of C-glycosyl xanthones from Coffea pseudozanguebariae and their location

The biochemical composition of leaves from Coffea pseudozanguebariae, a wild caffeine-free coffee species, was determined. Two phenolic compounds were extracted from leaves, separated and characterized. Their structures were elucidated by mass spectrometry, and 1D and 2D NMR spectroscopy and were shown to be mangiferin (1) and isomangiferin (2), which were the main polyphenol products. Multiphoton fluorescence imaging was performed to visualize polyphenol distribution in leaf cross sections. Consistent biochemical analysis cell imaging techniques on leaves revealed yellow fluorescence in the epidermis and parenchyma cells corresponding to xanthone compounds.     

Sesquiterpene compounds from Inula viscosa

Two new compounds, 2,5-dihydroxyisocostic acid and 2,3-dihydroxycostic acid together with three known sesquiterpene compounds, Isocostic acid, Carabrone and Tomentosin, have been isolated from the acetone extract of Inula viscosa (L.) Aiton. The structures of all new compounds were determined by spectroscopic methods, in particular 1D and 2D (1)H- and (13)C-NMR. The (13)C-NMR spectra of Isocostic acid and of Tomentosin are reported here for the first time.     

Antioxidant, anti-glycation and anti-inflammatory activities of phenolic constituents from Cordia sinensis

Nine compounds have been isolated from the ethyl acetate soluble fraction of C. sinensis, namely protocatechuic acid (1), trans-caffeic acid (2), methyl rosmarinate (3), rosmarinic acid (4), kaempferide-3-O-β-D-glucopyranoside (5), kaempferol-3-O-β-D-glucopyranoside (6), quercetin-3-O-β-D-glucopyranoside (7), kaempferide-3-O-α-L-rhamnopyranosyl (1→6)-β-D-glucopyranoside (8) and kaempferol-3-O-α-L-rhamno-pyranosyl (1→6)-β-D-glucopyranoside (9), all reported for the first time from this species. The structures of these compounds were deduced on the basis of spectroscopic studies, including 1D and 2D NMR techniques. Compounds 1-9 were investigated for biological activity and showed significant anti-inflammatory activity in the carrageen induced rat paw edema test. The antioxidant activities of isolated compounds 1-9 were evaluated by the DPPH radical scavenging test, and compounds 1, 2, 4 and 7-9 exhibited marked scavenging activity compared to the standard BHA. These compounds were further studied for their anti-glycation properties and some compounds showed significant anti-glycation inhibitory activity. The purity of compounds 2-5, 8 and 9 was confirmed by HPLC. The implications of these results for the chemotaxonomic studies of the genus Cordia have also been discussed.