Seco-neferine A-F, three new pairs of benzyltetrahydroisoquinoline alkaloid epimers from Plumula Nelumbinis and their activity.

Three new pairs of benzyltetrahydroisoquinoline (BIQ) alkaloid epimers, Seco-neferine A-F (1-6), were isolated from an EtOH extract of Plumula Nelumbinis. The structures of these compounds were identified by a combination of NMR, HR-ESI-MS, circular dichroism, UV spectroscopic analyses and specific rotations. The structure of compounds 1-6 possesses high similarity with neferine, because these three pairs of epimers have the same skeleton as neferine. Compounds 1,2 and 5,6 are open-loop compounds of position 1' and 1 of neferine respectively. The H connects with position 2' N of compounds 1,2 is replaced by methyl, forming the structure of compounds 3,4. Moreover, six compounds were tested for cytotoxicity against MDA-MB-231 breast cancer cell. Compound 6 displayed moderate inhibitory effects on breast cancer with IC50 of 38.96 µM, while compounds 2,3,4 show certain inhibitory effects.

Compounds with inhibitory activity on peristalsis from the seeds of Holarrhena antidysenterica.

Eight compounds were isolated from the seeds of Holarrhena antidysenterica Wall.ex A.DC. On the basis of physico-chemical properties and spectroscopic data, holarrhenanan (1) was identified as a new compound, compounds 2-3 were isolated from H. antidysenterica for the first time, and five known compounds were also obtained. Inhibitory effects of some compounds and extracts to the intestinal peristalsis were evaluated. Results showed that the extracts and compounds 4, 6 exhibited remarkable inhibitory effects with tension inhibition rate of 32.77, 32.77% and amplitude inhibition rate of 59.51, 55.98%, respectively on the vitro rabbit intestinal peristalsis.

Antibacterial steroidal alkaloids from Holarrhena antidysenteriaca.

Two new steroidal alkaloids, isoconkuressine and N-formylconessimine, together with 6 known steroidal alkaloids including conkuressine, conessine, isoconessimine, conimine, conarrhimine, and funtudienine, were isolated from the seeds of Holarrhena antidysenteriaca Wall.ex A.DC. Their intrinsic antibacterial activities and synergistic effects with penicillin and vancomycin were analyzed in methicillin sensitive staphylococcus aureus (MSSA) and methicillin resistant staphylococcus aureus (MRSA). Two of the steroidal alkaloids including one new compound (N-formylconessimine) showed potential antibacterial activity and possessed synergistic effects with penicillin and vancomycin, respectively.

New Isocoumarins and Related Metabolites from Talaromyces flavus.

Two new isocoumarin derivatives, talaisocoumarins A (1) and B (2), and three new related metabolites, talaflavuols A-C (3-5) were isolated from the wetland soil-derived fungus Talaromyces flavus BYD07-13. Their structures were elucidated by spectroscopic (NMR) and MS analyses. The absolute configurations of 1 and 2 were determined by CD and an Rh2(OCOCF3)4-induced CD method. All compounds were evaluated for cytotoxic and antimicrobial activities. However, none of them showed any activity. The plausible biosynthetic pathways for 1-5 were also proposed.

Two new isoxazolines from the husks of Xanthoceras sorbifolia Bunge.

Two new isoxazoline compounds, 1-oxa-2-azaspiro[4.5]dec-2-ene-8ß-ol (1) and 1-oxa-2-azaspiro[4.5]dec-2-ene-8α-ol (2), were isolated from the husks of fruits of Xanthoceras sorbifolia Bunge and their structures were determined by spectroscopic analyses, including X-ray crystallography, HRESI-MS, UV, IR, and 1D and 2D NMR (HSQC, HMBC, NOESY) methods. Neither compound showed significant inhibitory effects on butyrylcholinesterase (BuchE) and acetylcholinesterase (AChE), nor the selected tumor cells growth. Based on an online activity prediction program (PASS ONLINE), the structures with isoxazoline skeletons were found to show potential anti-asthmatic (AM) and anti-anaphylaxis (AP) activities; moreover, compounds 1 and 2 were predicted to possess high affinities for many enzymes involved in AM and AP according to the RCSB Protein Data Bank. High-affinity binding to phosphodiesterase IV (PDE-4), an important inflammatory modulator in asthma, was demonstrated experimentally, beside that, the predicted structures based on compounds 1 and 2 were analyzed for PDE-4 interactions using the molecular docking methodology of Discovery Studio 3.0 (DS 3.0). The predicted structure 2A-6 exhibited much higher affinity and stability of PDE-4 binding than the clinical PDE-4 inhibitor rolipram.

Identification and analysis of alkaloids in cortex Phellodendron amurense by high-performance liquid chromatography with electrospray ionization mass spectrometry coupled with photodiode array detection.

Alkaloids from Cortex Phellodendron amurense Rupr. were identified to determine the material basis for the bioactivity of this herb. HPLC-ESI-MS with photodiode array detection coupled to XCharge C18 column was applied to analyze the alkaloids qualitatively and quantitatively. A total of 37 alkaloids were identified and tentatively characterized from the ethanol extract by online ESI-MS(n) fragmentation and UV spectral analysis. A total of ten alkaloids, including four novel natural products, were tentatively identified for the first time in P. amurense. The fragmentation pathways for certain compounds were analyzed. The contents of a pair of isomers (columbamine and jatrorrhizine) and four main alkaloids (phellodendrine, magnoflorine, berberine, and palmatine) were simultaneously quantified using the aforementioned method. Results showed that the newly discovered and known components of P. amurense were helpful in determining the material basis for the bioactivity of the herb. The application of the XCharge C18 column is a suitable and practical method for the isolation of alkaloids in plants.

Three new triterpenoids from Panax ginseng exhibit cytotoxicity against human A549 and Hep-3B cell lines.

Three new triterpenoid derivatives, 3-O-ß-D-glucopyranosyl-20(S)-protopanaxtriol (1), 3-formyloxy-20-O-ß-D-glucopyranosyl-20(S)-protopanaxtriol (2) and 26-hydroxyl-24(E)-20(S)-protopanaxtriol (3), along with six known ginsenosides, were isolated from leaves of Panax ginseng. Their structures were established on the basis of spectral analysis (IR, 1D and 2D NMR, HRESI-MS). Compounds 1-3 exhibited various degree of cytotoxicity towards human A549 pulmonary carcinoma cells and Hep3B hepatoma cells.

Constituents from the testas of Castanea mollissima Blume with alpha-glucosidase inhibitory activity.

In the screening of biologically active constituents from medicinal plants, the 75% EtOH extract of the testas of Castanea mollissima Blume showed potent alpha-glucosidase inhibitory activity. By means of various chromatographic methods, the extract gave a new dammarane-type triterpene 1 along with 17 known compounds. The structure of 1 was determined to be 3beta-acetoxy-20-oxo-21-nordammaran-23-oic acid by HRMS and NMR studies including 2D NMR experiments. The new compound and some known compounds showed potent alpha-glucosidase inhibitory activity with acarbose as a positive control.

Structure and absolute configuration of a diterpenoid from Castanea mollissima.

From the nuts of Castanea mollissima Blume, a new kauranoid diterpene glycoside, named mollioside (1), was isolated. Its structure was established as (4R, 5S, 6R, 8R, 9S, 10S, 13R, 16R) 17-O-beta-D-glucopyranoside, ent-6,7-epoxy-6alpha-hydroxyl-6,7-secokaur-19-oic acid, 6, 19-lactone-16beta, 17-diol on the basis of HR-FAB-MS, 1D, 2D-NMR and CD spectral analysis. The aglycone (1a, named mollissin), also as a new compound, was obtained after enzymatic hydrolysis of 1. Both compounds exhibited significant growth inhibitory activity on HeLa tumor cells, but no activity on A375-S2.

Two novel A-seco-rearranged lanostane triterpenoids from Abies sachalinensis.

Further chemical study led to two new A-seco-rearranged lanostane triterpenoid derivatives (1-2) and one known compound Abiesanolide C (3) from the ethyl acetate (EtOAc) soluble fraction of the MeOH extract of Abies sachalinensis needles. The new compounds were identified as 3,4-seco-8-(14-->13R)abeo-17,13-friedo-9beta-lanosta-4(28), 7, 14, 24-tetraen-26,23-olide-23-hydroxy-3-oic acid and methyl-3,4-seco-8-(14-->13R) abeo-17,13-friedo-9beta-lanosta-4(28), 7, 14, 24-tetraen-26,23-olide-23-hydroxy-3-oate, respectively. Structural determination of these compounds were carried out by the spectral studies especially by the two digital (2D)-NMR and high-resolution (HR)-MS experiences.

[Neocaesalpin L1, a new diterpenoid compound from Caesalpinia minax].

OBJECTIVE: To study the chemical constituents of Caesalpinia minax. METHOD: The chemical constituent was isolated by various chromatographic metheds and its structure was elucidated by the analysis of spectral data and physiochemical properties. RESULT: One diterpenoid compound was isolated from the 95% ethanolic extract of C. minax, and identified as 12alpha -methoxyl-14beta-hydroxy-lalpha, 6alpha, 7beta-triacetoxycass-13 (15)-en-16, 12-olide. CONCLUSION: Neocaesalpin L1 was a new compound and named as neocaesalpin L1.

Bioactive constituents from Chinese natural medicines. XIV. New glycosides of beta-carboline-type alkaloid, neolignan, and phenylpropanoid from Stellaria dichotoma L. var. lanceolata and their antiallergic activities.

A new beta-carboline-type alkaloidal glycoside, glucodichotomine B, four new neolignan glycosides, dichotomosides A, B, C, and D, and a new phenylpropanoid glycoside, dichotomoside E, were isolated from a Chinese natural medicine, the roots of Stellaria dichotoma L. var. lanceolata. The structures of the new glycosides were determined on the basis of chemical and physicochemical evidence. Among them, dichotomoside D inhibited the release of beta-hexosaminidase (IC(50)=64 microM) as well as tumor necrosis factor-alpha and interleukin-4 (IC(50)=16, 34 microM) in RBL-2H3 cells. These findings suggest that dichotomoside D is more effective against the late-phase reactions in type I allergy than in the immediate phase.

Structures of new beta-carboline-type alkaloids with antiallergic effects from Stellaria dichotoma(1,2).

The aqueous ethanolic extract from the roots of Stellaria dichotoma showed an antiallergic effect on ear passive cutaneous anaphylaxis (PCA) reaction in mice (in vivo) and inhibitory activity on the release of beta-hexosaminidase in RBL-2H3 cells (in vitro). From the aqueous ethanolic extract, new beta-carboline-type alkaloids, dichotomines A (1), B (2), C (3), and D (4) and dichotomides I (5) and II (6), were isolated. The structures of the new constituents (1-6) were determined on the basis of chemical and physicochemical evidence, including the application of the modified Mosher's method. The effects of the isolated constituents on the release of beta-hexosaminidase in RBL-2H3 cells were examined, and 3 was found to show inhibitory activity (IC(50) = 62 microM). Moreover, 3 also inhibited the releases of antigen-IgE-mediated TNF-alpha and IL-4 (19 and 15 microM, respectively) in RBL-2H3 cells, both of which participate in the late phase of type I allergic reactions.