Active Constituents with Tyrosinase Inhibitory Activities from Waste Tobacco Leaves.

One novel compound, (R)-3, 6-diethoxy-4-hydroxycyclohex-3-en-1-one (1) and thirteen known compounds were isolated from the waste tobacco leaves. The structures of two compounds (1-2) were confirmed and attributed firstly by the extensive spectroscopic data, including 1D/2D NMR, IR, HR-ESI-MS, CD, and ECD spectra. Notably, seven compounds (2, 3, 9, 10, 11, 12, and 13) exhibited better tyrosinase inhibitory activity than the positive control kojic acid. The binding modes of these compounds revealed that their structure formed strong hydrogen bonds and van der Waals forces with the active sites of tyrosinase. These results indicated that waste tobacco leaves are good resources for developing tyrosinase inhibitors.

Three New Constituents with Anti-Inflammatory and Antimicrobial Activities in Vitro from the Roots of Capsicum annuum L.

Three new compounds, including two new sesquiterpenes (1-2), named Annuumine E-F, and one new natural product, 3-hydroxy-2,6-dimethylbenzenemethanol (3), together with seventeen known compounds (4-20) were isolated from the ethanol extract of the roots of Capsicum annuum L. Among them, five compounds (4, 5, 9, 10 and 20) were isolated from this plant for the first time. The structures of new compounds (1-3) were determined via detailed analysis of the IR, HR-ESI-MS and 1D and 2D NMR spectra. The anti-inflammatory activities of the isolated compounds were evaluated by their ability to reduce NO release by LPS-induced RAW 264.7 cells. Notably, compound 11 exhibited moderate anti-inflammatory activity (IC50 =21.11 µM). Moreover, the antibacterial activities of the isolated compounds were also evaluated.

Active constituents with α-glucosidase inhibitory activities from Sabia parviflora.

To identify the active constituents with α-glucosidase inhibitory activities in Sabia parviflora, three new compounds, namely, sabiaparviflora A-C (1, 2 and 8), and seven known compounds were isolated from the plant by repeated column chromatography. The structures of the new compounds were identified by extensive application of spectroscopic methods, including 1H NMR, 13C NMR, IR and HR-ESI-MS. All compounds, except for compounds 3-5, 9 and 10 were isolated for the first time from S. parviflora. Their α-glucosidase inhibitory activities were evaluated for the first time by the PNPG method. Three compounds (1, 7 and 10) exhibited marked activities, with IC50 values ranging from 104 to 324 µM, and their structure-activity relationship is preliminarily discussed herein.

Pentacyclic Triterpenoids from Sabia discolor Dunn and Their α-Glycosidase Inhibitory Activities.

Four new pentacyclic triterpenoids named Sabiadiscolor A-D (1 and 7-9) together with eleven known ones were isolated by repeated column chromatography. Their structures were identified and characterized by NMR and MS spectral data as 6 oleanane-type pentacyclic triterpenoids (1-6), 7 ursane-type ones (7-13), and 2 lupanane-type ones (14-15). Except for compound 15, all other compounds were isolated from Sabia discolor Dunn for the first time. Their α-glycosidase inhibitory activities were evaluated, which showed that compounds 1, 3, 8, 9, 13, and 15 implied remarkable activities with IC50 values ranging from 0.09 to 0.27 µM, and the preliminary structure-activity relationship was discussed.

Hepatoprotective Constituents of Total Dibenzocyclooctadiene Lignans from Schisandra chinensis Based on the Spectrum-Effect Relationship.

To scientifically clarify the hepatoprotective constituents of Fructus Schizandrae chinensis, eleven batches samples of total dibenzocyclooctadiene lignans (TDL) from Schisandra chinensis were prepared by using the optimum extraction technique. Characteristic high-performance liquid chromatography (HPLC) chromatograms were obtained through HPLC analysis technology, and the hepatoprotective effects of the eleven batches of TDL were evaluated by MTT assay. Based on the chemical and biological activity results, the spectrum-effect relationship between the characteristic HPLC fingerprints and the hepatoprotective effect of TDL was established using Minitab 16.0 data analysis software. On the basis of the spectrum-effect relationship, thirteen compounds (1-13) were obtained from the TDL by chemical natural product chemical separation and purification technology, and their structures were identified on the basis of the spectral data and the literature. Based on these compounds, thirteen common peaks among the thirty-three chromatographic peaks in the above HPLC fingerprints were identified. Our findings showed that some components, including, schisandrin B (2), schisandrin A (3), and schisandrol B (7) had significant roles in promoting hepatoprotective activity. Preliminary verification of the spectrum-effect relationship of TDL from S. chinensis was carried out, and the results confirmed that the activity of a composite of these three key components in optimal ratios was better than that of any individual compound, which potentially confirmed the reliability of the spectrum-effect relationship and the synergistic effects of traditional Chinese medicine.

Regioselective alkali metal reduction of dibenzocyclooctadiene lignan derivatives, demethoxylation followed by dehalogenation.

The regioselective demethoxylation and dehalogenation of dihalogenated dibenzocyclooctadiene lignans derivatives were realized in a one-step reaction with excellent yields in the sodium and t-butanol reaction system.

Synthesis and evaluation of antifungal activity of C21-steroidal derivatives.

The antifungal activities of eleven C21-steroidal compounds isolated from Cynanchum wilfordii, together with thirty-six derivatives of caudatin and qingyangshengenin were evaluated on Sclerotinia sclerotiorum and other five fungal strains by the mycelium growth rate method. Four derivatives 1k, 1y, 10d, and 10j exhibited much stronger inhibitions on growth of S. sclerotiorum with IC50 values of 0.0084, 0.0049, 0.0053, and 0.0034 µM, respectively.

Schisanhenol derivatives and their biological evaluation against tobacco mosaic virus (TMV).

Schisanhenol (Sol) was isolated from Schisandra rubriflora, and a series of derivatives (1-16, 15a-16a, and 15b-16b) were designed and prepared by chemical modification. The curative and protective effects of these dibenzocyclooctadiene lignan analogues against tobacco mosaic virus (TMV) were evaluated. Most analogues exhibited stronger protective effects than the positive control ningnanmycin. Dibromoschisanhenol (6) at 0.25mM exhibited the strongest protective activity (83.5±1.8% at 0.25mM), and 14-(3, 5-dibenzyloxy)-benzoyloxyschisanhenol (16) showed a significant curative effect (78.0±3.8% at 0.15mM) that was much stronger than that of the commercial virucide ningnanmycin. This study is the first to demonstrate that natural dibenzocyclooctadiene lignans and analogues are active against plant viruses.

Studies on cytotoxic pregnane sapogenins from Cynanchum wilfordii.

To investigate their cytotoxicity, seventeen C21-steroidal pregnane sapogenins 1-17 were isolated from the hydrolytic extracts of the roots of Cynanchum wilfordii. Among them, sapogenins 1-7 are new compounds, whose structures were determined by extensive analysis of spectroscopic data and X-ray crystallographic analysis. Especially, sapogenins with salicyl or vanilloyl group, and a new aberrant pregnane skeleton with ether linkage between C-12 and C-20 were found for the first time. Compound 1 revealed significant cytotoxicities on HL-60 (IC50 6.72µM) and MCF-7 (IC50 2.89µM), and compounds 14 and 15 also revealed strong inhibitory activities against K-562 (IC50 6.72µM) or MCF-7 (IC50 2.49µM), respectively.

Triterpenoids with anti-tobacco mosaic virus activities from Melia toosendan.

Four new triterpenoids, named Toosendansins A-D (1-4), along with nine known ones (5-13) were isolated from the fruits of Melia toosendan Sieb. et Zucc. Their structures were established on the basis of spectroscopic data. The isolation of compounds 1-12 were reported for the first time from this plant. All compounds were analyzed for the anti-Tobacco Mosaic Virus (TMV) activity and protective effect on H2O2-induced damage of SH-SY5Y cells. Compound 7 showed evident anti-TMV activity. Compounds 2 and 9 exhibited modest protection against H2O2-induced damage of SH-SY5Y cells.

Seco-pregnane steroidal glycosides from the roots of Cynanchum atratum and their anti-TMV activity.

Fifteen new seco-pregnane steroidal glycosides cynanosides A-O (1-15) together with twenty-seven known ones were isolated from the roots of Cynanchum atratum. The structures of 1-15 were determined by extensive analysis of spectroscopic data. The anti-tobacco mosaic virus (TMV) activity of these steroidal glycosides was screened by the conventional half-leaf method, enzyme-linked immunosorbent assay, and Western blot methods, most of them showed potent anti-TMV activity. Among them, compounds 1, 7, 13, 28 and 31 showed significantly anti-TMV activity with an IC50 value of 20.5, 18.6, 22.0, 19.2 and 22.2 µg/mL, respectively, and were much more effective than the positive control, ningnanmycin (IC50=49.6 µg/mL).

Synthesis and the hepatoprotective activity of dibenzocyclooctadiene lignan derivatives.

The halogenated and oxidized derivatives (1a-1e, 1a'-1c', 2a-2d, 2a'-2b', 3a-3e, 3' and 3a'-3b') of schizandrin (1), schizandrin B (2) and schisanhenol (3) were synthesized. The hepatoprotective effects of these dibenzocyclooctadiene lignan analogues against CCl4-induced injury were preliminarily evaluated. Most of the analogues exhibited higher protective effects than the positive control biphenyldicarboxylate (DDB). Among these active analogues, dichloroschisanhenol (3a) exhibited the strongest protective activity (cell survival rate exceeding 98.0%).

[Study on chemical constituents of Euphorbia helioscopia and their antitumor activities].

OBJECTIVE: To investigate the chemical constituents of Euphorbia helioscopia and their antitumor activities. METHODS: Normal phase silica gel, RP-18 silica gel and Sephadex LH-20 column chromatographies combined with recrystallization were used to isolate and purify the constituents. Their structures were identifided by spectroscopic methods, including 1H-NMR, 13C-NMR, ESI-MS and EI-MS. And the antitumor activities of some of chemical constituents in vitro were detected by sulphorhodamine B protein staining. RESULTS: Nine compounds were isolated and their structures were identified as euphohelioscopin A (1), euphoscopin (2), 9, 19-cyclolanost-23E-ene-3, 25-diol (3), euphoscopin C (4), euphornin A (5), euphoheliosnoid A (6), ent-kaurane-3-oxo-16beta, 17-diol (7), 9, 19-cyclolanost-25-ene-3beta, 22-diol (8) and helioscopinolide A(9) Compound 9 showed effect on inhibiting the cell proliferations of MCF-7 cell line. CONCLUSION: Compounds 3, 7, 8 and 9 are obtained from this plant for the first time, and compound 9 shows the potential antitumor activity.

The limonoids and their antitobacco mosaic virus (TMV) activities from Munronia unifoliolata Oliv.

Five new limonoids, named munronoids K-O (1-5), together with three known limonoids were isolated from Munronia unifoliola Oliv. These limonoids were involved in the skeletons of evodulone, gedunin, and peieurianin types of limonoids, and their structures were established on the basis of spectroscopic data. Compound 5 featuring a γ-lactone ring instead of the ß-substituted furan ring was found in the peieurianin type for the first time. The antitobacco mosaic virus (anti-TMV) activities of compounds 1-8 were also evaluated with half-leaf, enzyme-linked immunosorbent assay, and Western blot methods, and limonoids 1, 5, and 8 showed stronger anti-TMV treatment activities than the positive control ningnanmycin. Six compounds (1-5 and 8) exhibited infection inhibition activities against TMV.

[Study on the chemical constituents of fructus gardeniae].

OBJECTIVE: To investigate the chemical constituents of Fructus Gardeniae. METHODS: Normal phase silica gel, RP-18 silica gel and Sephadex LH-20 column chromatographies combined with recrystallization were used to isolate and purify the constituents. Their structures were identified by spectroscopic methods, including 1H-NMR, 13C-NMR, ESI-MS and EI-MS. RESULTS: Seven compounds were isolated. Their structures were identified as geniposide (I), 6alpha-hydroxygeniposide (II), genipin-gentiobioside (III), adian-5-en-3alpha-ol (IV), (23Z) -cycloart-23-en-3beta,25-diol (V), 7alpha-hydroxy sitosterol (VI) and 5,8-epidioxystigmasta-6,22-dien-3-ol (VII) from ethanol extract of Fructus Gardeniae. CONCLUSION: Compounds IV, V, VI and VII are obtained from this plant for the first time.

New diterpenoids from the roots of Euphorbia ebracteolata Hayata.

Three new diterpenoids, ingenol-5ß,20-O,O-isopropylidene-3ß-palmitate, ingenol-5ß,20-O,O-isopropylidene-3ß-myristinate and 3ß,19-dihydroxy-1(10),15-rosadien-2-one, were isolated from the roots of Euphorbia ebracteolata Hayata. Their structures were deduced by spectroscopic means and analytic techniques.

[Studies on the chemical constituents from Euphorbia chrysocoma].

OBJECTIVE: To study the chemical constituents from the aerial part of Euphorbia chrysocoma. METHODS: All compounds were isolated and purified by many methods, including siliga gel and reversed phase RP-18 column chromatographies, preparative thin layer chromatography, Sephadex LH-20, and recrystallization. Their structures were mainly elucidated by ESI-MS and NMR spectra and their physical characters. RESULTS: Six compounds were isolated from the petroleum ether section from 75% ethanol extraction of the material. Their structures were identified as taraxerol (1), epitaraxerol (2), beta-sistosterol (3), beta-sitostenone (4), jolkinolide E (5), and sesamin (6). CONCLUSION: Compounds 1, 2, 4, 5, and 6 are isolated from this plant for the first time.

Daphhimalenine A, a new alkaloid with an unprecedented skeleton, from Daphniphyllum himalense.

Daphhimalenine A (1), a novel alkaloid with a rearrangement C-21 skeleton, containing a unique 1-azabicyclo[5.2.1]decane ring system, was isolated from the leaves of Daphniphyllum himalense, along with biogenetically related alkaloids daphhimalenine B (2) and daphnezomine T. Their structures were established on the basis of spectroscopic data, and the absolute configuration of 1 was assigned by computational methods. A plausible biosynthetic pathway of 1 was also proposed.

Dapholdhamines A-D, alkaloids from Daphniphyllum oldhami.

Four new Daphniphyllum alkaloids, dapholdhamines A-D (1-4), were isolated from the leaves of Daphniphyllum oldhami. The structures and relative configurations of 1-4 were elucidated on the basis of spectroscopic data.

Daphniphyllum and diterpenoid alkaloids from Daphniphyllum longeracemosum.

Four new Daphniphyllum alkaloids, daphlongamines A-D (1-4), were isolated from the fruits of Daphniphyllum longeracemosum. Their structures were characterized by spectroscopic methods, especially 2D NMR techniques. A single-crystal X-ray diffraction analysis was used to confirm the stereochemistry of 3. Remarkably, this is the first report of aconitine- and veatchine-type diterpenoid alkaloids from the genus Daphniphyllum.