Structures of New Aromatics Glycosides from a Japanese Folk Medicine, the Roots of Angelica furcijuga

Phytochemicals with Chemopreventive Activity Obtained from the Thai Medicinal Plant Mammea siamensis (Miq.) T. Anders.: Isolation and Structure Determination of New Prenylcoumarins with Inhibitory Activity against Aromatase

With the aim of searching for phytochemicals with aromatase inhibitory activity, five new prenylcoumarins, mammeasins K (1), L (2), M (3), N (4), and O (5), were isolated from the methanolic extract of Mammea siamensis (Miq.) T. Anders. flowers (fam. Calophyllaceae), originating in Thailand. The stereostructures of 1–5 were elucidated based on their spectroscopic properties. Among the new compounds, 1 (IC₅₀ = 7.6 µM) and 5 (9.1 µM) possessed relatively strong inhibitory activity against aromatase, which is a target of drugs already used in clinical practice for the treatment and prevention of estrogen-dependent breast cancer. The analysis through Lineweaver–Burk plots showed that they competitively inhibit aromatase (1, Ki = 3.4 µM and 5, 2.3 µM). Additionally, the most potent coumarin constituent, mammea B/AB cyclo D (31, Ki = 0.84 µM), had a competitive inhibitory activity equivalent to that of aminoglutethimide (0.84 µM), an aromatase inhibitor used in therapeutics.

Polyphenolic Glycosides from the Fruits Extract of Lycium ruthenicum Murr and Their Monoamine Oxidase B Inhibitory and Neuroprotective Activities

The fruits ofLycium ruthenicum Murr have long been consumed as health food and used in folk medicine in China. Apart from the well-known polysaccharides, the active small molecular constituents in this fruit have not been fully studied. In this work, a systematic phytochemical study was carried out to investigate the small molecules and their potential health benefits. Nine new polyphenolic glycosides, lyciumserin A-I (1-9), together with 16 known compounds (10-25), were isolated and elucidated by high-resolution electrospray ionization mass spectrometry and comprehensive NMR analyses in combination with chemical hydrolysis. Compounds 1, 2, and 16 exhibited moderate inhibitory activity of monoamine oxidase B (MAO-B), while compounds 1 (50 μM) and 2 (100 μM) displayed significant neuroprotective effects (69.22 and 72.38% of cell viability, respectively) in the 6-hydroxydopamine-induced injury of the PC12 cell model (54.41%), comparable to the positive drug rasagiline (70.45%). The neuroprotective effect of 1 and 2 was further evidenced by the observation of the morphological change and fluorescein diacetate/propidium iodide staining. In addition, the levels of the major active compounds (1, 3, 5/6, and 16-18) vary from 21.5 to 892.3 μg/g. This is the first report on phenolic glycosides from the fruits ofL. ruthenicum Murr that possess both significant MAO-B inhibitory and neuroprotective effects, indicating the promising potential of the fruits for the development of health care products and even therapeutic agents for the treatment of Parkinson's disease and other neurodegenerative diseases.

A concise approach for determining the relative configuration of H-7 and H-8 in 8,4′-oxyneolignans by 1H NMR spectroscopy

The chemical shift difference between H-9a and H-9b can be used to accurately and rapidly determine the relative configuration of H-7 and H-8 in three types of 8,4′-oxyneolignan glucosides.

A new C-glycosyl flavone and a new neolignan glycoside from Passiflora edulis Sims peel

A new C-glycosyl flavone, Chrysin-8-C-(2″-O-β-6-deoxy-glucopyranosyl)-β-D-glucopyranoside (1), a new neolignan glycoside, citrusin G (2), as well as 15 known compounds (3-17) were isolated from the peel of Passiflora edulis Sims. The structure determinations were primarily based on comprehensive spectroscopic analyses, and the absolute configuration of 2 were unequivocally determined by the CD experiment and chemical transformation. Compound 1 represents the rare examples of the flavonoid featuring a deoxy glucose sugar moiety. Compounds 5, 7 and 9 exhibited moderate inhibitory effects on nitric oxide (NO) production stimulated by lipopolysaccharide (LPS) in RAW 264.7 cells, with IC₅₀ values of 34.92, 16.12 and 26.67 μM, respectively.

Evaluation of a furochromone from the halophyte Corydalis heterocarpa for cytotoxic activity against human gastric cancer (AGS) cells

A furochromone, heterocarpin (1), was isolated from the halophyte Corydalis heterocarpa, along with four known compounds (2-5), which were obtained for the first time from this genus. The chemical structures of these compounds were determined by extensive 2-D NMR experiments and by comparison with the data reported in the literature. Compound 1 showed significant cytotoxic activities against four human cancer cells, AGS (human gastric cancer), HT-29 (human colon cancer), HT-1080 (human fibrosarcoma) and MCF-7 (human breast carcinoma). According to the cytotoxicity results, the mechanism behind the cytotoxic presence of compound 1 on AGS cells was investigated through the mRNA and protein levels of apoptotic pathway factors such as p21, p53, Bax, Bcl-2, XIAP, and caspases-3 and -9. The results indicated that heterocarpin (1) showed the cytotoxic effect on cancer cells by inducing apoptosis via regulated Bax-Bcl-2 ratio, overproduced caspases and suppressed XIAP. The inhibition of NFκB and activation of JNK and ERK pathways were also observed in the presence of heterocarpin (1). Therefore, heterocarpin and its source C. heterocarpa were suggested to be utilized as a functional food with potential pro-apoptotic activity against cancer cells.

Anti-Inflammatory Activity of Heterocarpin from the Salt Marsh Plant Corydalis heterocarpa in LPS-Induced RAW 264.7 Macrophage Cells

The inhibitory effect of three chromones 1-3 and two coumarins 4-5 on the production of nitric oxide (NO) was evaluated in LPS-induced RAW 264.7 macrophage cells. Among the compounds tested heterocarpin (1), a furochromone, significantly inhibited its production in a dose-dependent manner. In addition, heterocarpin suppressed prostaglandin E2 (PGE2) production and expression of cytokines such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6).

Enantiomeric determination of four diastereoisomeric oxyneolignans from Bambusa tuldoides Munro

INTRODUCTION

Bambusa tuldoides Munro, a bamboo species, is used as a health food, dietary supplement and folk medicine in China, and produces lignans that can be used to supplement other natural sources.

OBJECTIVE

To simultaneously separate eight stereoisomers of a particular type of oxyneolignan by chiral chromatography.

METHODS

Ninety-five per cent ethanol extracts of B. tuldoides Munro were analysed using HPLC/UV with a chiral column. The structures and configurations of isolated compounds were elucidated using NMR and circular dichroism (CD).

RESULTS

Four diastereoisomers were characterised and given the names oxyneolignans A, B, C and D. Furthermore, each oxyneolignan occurred as a pair of enantiomers. The oxyneolignans A-D consisted of the erythro-diastereoisomer of oxyneolignan at C7 and C8.

CONCLUSION

The chiral chromatography combined with the analysis techniques of NMR and CD reported here were reliable methods for discovering and separating the enantiomers.

Lignans and neolignans from Sinocalamus affinis and their absolute configurations

Twenty-two new lignans and neolignans (1-22), together with 14 known analogues, have been isolated from an ethanolic extract of the stem (with skin removed) of Sinocalamus affinis. Their structures were elucidated by spectroscopic and chemical methods. On the basis of systematic NMR and circular dichroism (CD) data analysis, the validity of J7,8 and ΔδC8-C7 values to distinguish threo and erythro aryl glycerol units in different neolignans and the CD data [particularly the Rh2(OCOCF3)4-induced CD data (the E band)] to determine the absolute configurations at C-8 (C-7) of the aryl glycerol units are discussed. At a concentration of 10 μM, compounds 20 and 22 inhibited NO production in mouse peritoneal macrophages 84.2±5.9% and 71.7±1.0%, respectively. Compounds 19, 20, and 22 showed activity against serum deprivation induced PC12 cell damage by increasing the cell viability from 80.7±2.8% to 91.6±6.4%, 107.2±8.0%, and 97.6±8.5%, respectively.

Glycosides from Breynia fruticosa and Breynia rostrata

Glycosides, 3-acetyl-(-)-epicatechin 7-O-beta-glucopyranoside (1), 3-acetyl-(-)-epicatechin 7-O-(6-isobutanoyloxyl)-beta-glucopyranoside (2), 3-acetyl-(-)-epicatechin 7-O-[6-(2-methyl-butanoyloxyl)]-beta-glucopyranoside (3), (5Z)-6-[5-(2-hydroxypropan-2-yl)-2-methyl-tetrahydrofuran-2-yl]-3-methylhexa-1,5-dien-3-O-beta-glucopyranoside (4), hydroquinone O-[6-(3-hydroxyisobutanoyl)]-beta-galactopyranoside (5), 4-(4-O-beta-glucopyranosyl-phenoxy)-1-O-beta-glucopyranosyl-1,3-benzenediol (6), 7,8-erythro-dihydroxy-3,4,5-trimethoxy-phenyl-propane8-O-beta-glucopyranoside (7), 6,7-dimethylbenzofuranol 5-O-beta-xylopyranosyl-(1-->6)-beta-glucopyranoside (8), along with 30 known glycosides, were isolated from Breynia fruticosa and Breynia rostrata (Euphorbiaceae). Their structures were determined on the basis of spectroscopic analysis and chemical methods.

Two new neolignans from Syringa velutina Kom

Two new neolignans, (7S,8R)-guaiacylglycerol-8-O-4′-sinapyl ether 9′-O-β-D- glucopyranoside (1) and (7S,8R)-syringylglycerol-8-O-4′-sinapyl ether 9′-O-β-D-gluco- pyranoside (2) were isolated from the leaves of Syringa velutina Kom.. Their structures were established by chemical properties and spectroscopic evidence.

Glycosides from the root of Iodes cirrhosa

Seven new neolignan glycosides ( 1- 7), two arylglycerol glycosides ( 8, 9), and 18 known glycosides have been isolated from an ethanolic extract of the root of Iodes cirrhosa. Their structures including absolute configurations were determined by spectroscopic and chemical methods. Based on analysis of the NMR data of threo and erythro 8-4'-oxyneolignans and arylglycerols in different solvents, the validity of J 7,8 and Deltadelta C8-C7 values to distinguish threo and erythro derivatives was discussed. In the in vitro assays, compound 4 and liriodendrin ( 17) both showed activity against glutamate-induced PC12 cell damage at 10 (-5) M.

Antioxidative flavanone glycosides from the branches and leaves of Viscum coloratum

Two new flavanone glucosides, (2S)-homoeriodictyol 7,4'-di-O-beta-D-glucopyranoside (4) and (2R)-eriodictyol 7,4'-di-O-beta-D-glucopyranoside (5) were isolated from the branches and leaves of Viscum coloratum (KOMAR) NAKAI (Loranthaceae), along with three known flavanone glucosides: (2S)-homoeriodictyol 7-O-beta-D-glucopyranoside (1), (2S)-eriodictyol 7-O-beta-D-glucopyranoside (2), and (2S)-naringenin 7-O-beta-D-glucopyranoside (3). The structures of these compounds were elucidated using spectroscopic methods. The antioxidant activities of these isolated compounds were evaluated by colorimetric methods based on their scavenging effects on hydroxyl radicals and superoxide anion radicals, respectively. All the compounds showed potent albeit varied degrees of antioxidative activities and the structure-activity relationship is discussed.

Inhibitory effects of coumarin and acetylene constituents from the roots of Angelica furcijuga on d-galactosamine/lipopolysaccharide-induced liver injury in mice and on nitric oxide production in lipopolysaccharide-activated mouse peritoneal macrophages

The methanolic extract (200 mg/kg, p.o. and i.p.), principal coumarin constituents (isoepoxypteryxin, anomalin, and praeroside IV), and a polyacetylene constituent (falcarindiol) (25 mg/kg, i.p.) from the roots of Angelica furcijuga protected the liver injury induced by D-galactosamine (D-GalN)/lipopolysaccharide (LPS) in mice. In in vitro experiments, coumarin constituents (hyuganins A-D, anomalin, pteryxin, isopteryxin, and suksdorfin) and polyacetylene constituents [(-)-falcarinol and falcarindiol] substantially inhibited LPS-induced NO and/or TNF-alpha production in mouse peritoneal macrophages, and isoepoxypteryxin inhibited D-GalN-induced cytotoxicity in primary cultured rat hepatocytes. Furthermore, hyuganin A, anomalin, and isopteryxin inhibited the decrease in cell viability by TNF-alpha in L929 cells.

Inhibitors of Nitric Oxide Production from the Flowers of Angelica furcijuga: Structures of Hyuganosides IV and V

The methanolic extract from the flowers of Angelica furcijuga KITAGAWA was found to inhibit nitric oxide production in lipopolysaccharide-activated mouse peritoneal macrophages. From the methanolic extract, two new glycosides, hyuganosides IV and V, were isolated together with 28 known constituents. The structures of the new constituents were determined on the basis of chemical and physicochemical evidence. Furthermore, the inhibitory effects of 11 coumarin constituents on nitric oxide production were examined. Among them, 3'-angeloyl-cis-khellactone (IC(50)=82 microM), (S)-(-)-oxypeucedanin (57 microM), imperatorin (60 microM), isoepoxypteryxin (53 microM), and isopteryxin (8.8 microM) showed inhibitory activity.