Hepatoprotective and neuroprotective tocopherol analogues isolated from the peels of Citrus unshiu Marcovich

Three tocopherol analogues methoxytocopherol (1), α-tocopherol (2) and γ-tocopherol (3) were isolated from the peels of Citrus unshiu Marcovich. The protective effects of the isolated compounds against tert-butyl hydroperoxide-induced hepatotoxicity in human liver-derived HepG2 cells and glutamate-induced oxidative stress in HT22-immortalised hippocampal cells were evaluated. Compounds 1–3 were significantly protective in HepG2 cells with EC₅₀ values of 21.22 ± 2.01, 25.21 ± 2.11 and 25.25 ± 1.21 μM, respectively, and in HT22 cells, compounds 1–3 had EC₅₀ values of 20.62 ± 1.36, 6.44 ± 1.65 and 9.52 ± 1.54 μM, respectively.     

Isolation of a new cytotoxic polyhydroxysterol from the South China Sea soft coral Sinularia sp.

A new polyhydroxysterol, (22E)-24-methylenecholestane-22-ene-3β,5α,6β-triol (1), together with four known analogues (2–5) were isolated from the South China Sea soft coral Sinularia sp. Their structures were elucidated by spectroscopic analyses and comparison with previously reported data. All these compounds exhibited cytotoxic effect against both HepG2 and HeLa cell lines with IC₅₀ values ranging from 8.36 to 37.30 μM. Preliminary structure–activity relationship study identified that the presence of double bonds in the side chains of these polyhydroxysterols significantly reduced the biological effect obtained.     

DIBUTADIENYL PIPERAZINE,DIBUTADIENYL HOMOPIPERAZINES AND BUTADIENYL-SUBSTITUTED PIPERIDINES FROM MONOSUBSTITUTED HALODIENES

Compounds 3a–k were obtained from the reactions of compounds 1a–k with homopiperazine (2) in CH ₂ Cl ₂ . Compounds 1a–b, 1d–f, and 1h–l gave compounds 5a–b, 5d–f, and 5h–l with 2-methylpiperazine (4) in dichloromethane. Compounds 7c and 9c were obtained from the reactions of compound 1c with 4-ethoxycarbonyl piperazine (6) and 4-piperidinol (8) in CH ₂ Cl ₂ . Compounds 1a and 1f gave compounds 11a and 11f with 4-methylpiperazine (10), and compound 13f was obtained from the reactions of compound 1f with 4-methylpiperidine (12) in CH ₂ Cl ₂ .     

Chemical constituents from Gueldenstaedtia verna and their anti-inflammatory activity

A new triterpenoid glycoside (1) and 15 known compounds (2–16) were isolated from the whole plants of Gueldenstaedtia verna. The new compound (1) was identified as complogenin 22-O-β-d-glucopyranoside by extensive spectroscopic techniques including 1D (¹H and ¹³C) and 2D NMR experiments (HSQC, HMBC and NOESY), HR-DART-MS and chemical methods. Most of the isolates were evaluated for their inhibitory activities on LPS-induced NO production in RAW 264.7 cells. The inhibitory effects of the active compounds, sulphuretin (8) and (22E,24S)-5α,8α-epidioxy-24-methyl-cholesta-6,9(11),22-trien-3β-ol (13), on the production of pro-inflammatory mediators (including IL-6, IL1β and PGE₂) were further estimated in vitro by ELISA in RAW 264.7 macrophages.     

Circular Dichroism of Transition Metal Complexes and Sugar Derivatives Having a Free 1,3-Diol System or “Isolated” Hydroxyl Group

Abstract

Heptofuranose derivatives 1–6 having free 1, 3-diol systems form in situ complexes with Mo₂(OAc)₄ whose CD spectra permit the assignment of absolute configuration at C-5 using a sector rule proposed by G. Snatzke.^2–6 The interpretation of CD spectra of analogous complexes formed from derivatives 7–12 was more complicated and did not lead to direct configuralional conclusions. CD spectra of complexes formed from Rh₂(CF₃COO)₄ and sugar derivatives 13–21, containing an “isolated” hydroxyl group, permit the assignment of absolute configuration. Conclusions were corroborated by the investigation of CD spectra of rhodium complexes with compounds 22–27.     

Pictalignans D-F,three new neolignan derivatives from Selaginella picta

Abstract

Three new neolignan derivatives (1–3), together with three known isolariciresinol derivatives (4–6) were isolated from Selaginella picta. Their structures were elucidated by spectroscopic methods (1D/2D NMR, HRESIMS and CD). All isolated compounds were assayed on the neuroprotective activity against the injury of HT-22 cells induced by L-Glutamate in vitro. All compounds displayed potent protective effect on HT-22 cells.     

Coumarins and flavones from the fruit and root extracts of Micromelum integerrimum

A phytochemical investigation of the fruit and root extracts of Micromelum integerrimum resulted in the isolation and identification of a new compound, integerravone (1), together with 23 known compounds (2–24). Their structures were characterized by spectroscopic methods as well as comparisons made from the literature. Compounds 2, 3–15, 17–18 and 20–23 were evaluated for their cytotoxicities against the colon cancer cell line, HCT116. All of them were inactive at 50?µM. Most of the phenolic compounds were evaluated for their antioxidant activity using the DPPH assay. Compounds 14 and 22–24 showed antioxidant activity with IC₅₀ values ranging from 24.83-135.05?µM.     

Five macrocyclic glycosides from Schoenoplectus tabernaemontani

Macrocyclic glycosides with unique 22-membered dimeric lactone skeleton, are rare occurring natural products. There are only ten compounds reported so far. Herein we reported the isolation and characterisation of five macrocyclic glycosides from Schoenoplectus tabernaemontani, including three new compounds (Schoenopolide A-C, 1–3) and two known ones, Berchemolide (4) and Clemoarmanoside B (5). Their structures were established on the basis of extensive analysis of spectroscopic data. In addition, the anti-oxidative activity of Berchemolide (4) against H₂O₂-induced of renal tubular epithelial (HK-2) cells was also evaluated.     

Lignans from the seeds of Chinese hawthorn (Crataegus pinnatifida var. major N.E.Br.) against β-amyloid aggregation

Phytochemical investigation on the seeds of hawthorn (Crataegus spp.) led to the isolation of a new compound, (7′R, 8′R, 8S)-isolariciresinol (1), along with six known compounds (2–7). The structures of all compounds were determined based on spectroscopic data interpretation. The Aβ_1–42 inhibition activity of all isolated compounds was evaluated in vitro. As a result, compounds 5 and 6 showed stronger inhibition of Aβ_1–42 aggregation than curcumin, with inhibition rates of 70.59 and 68.14% at 20 μM. The possible mechanism of interaction between Aβ_1–42 and the active compounds 5 and 6 was also investigated by molecular docking.     

SYNTHESIS OF FUSED AND SPIRO HETEROCYCLIC COMPOUNDS DERIVED FROM 3,5-PYRAZOLIDINEDIONE DERIVATIVES

Abstract

The reaction of compound 1 with triethyl orthoformate afforded 2, which in turn reacted with CS₂ and active methlyene compounds or malononitrile to give dithiolane and 4-malononitrile methylene derivatives 3,4, respectively. Treatment of compound 4 with active methylene compounds afforded spiro cyclopentene derivatives 5_a-c. Compound 1 was reacted with bromomalononitrile or CS₂ and halocompounds to afford furo-. thieno- and dithiolano-pyrazole derivatives 6–11, respectively. The reaction of compound 12 with phenacyl bromide or benzylidenemalononitrile furnished oxathiol-2-ylidene and pyridinethione derivatives 13,14, respectively. The dibromo derivative 16 was reacted with CS₂ and active methylenes or malononitrile to obtain spiro dithietanes 17a-e and 4-dicyano-methlyene derivative 22, respectively. Compounds 17 underwent a cycloaddition reaction with thioglycolic acid, N-phenylbenzohydrazindoyl bromide, 2,5-dimethylfuran and 1-phenyl-3,5-pyrazolidinedi one to give cycloadducts 18–21, respectively. Treatment of > o-aminothiophenol or o-phenylenediamine with the dicyano compound 22 leads to the formation of spiro thiazepine or spiro diazine derivatives 23_a,b . The arylidene derivatives 24 was reacted with S,S-acetals, N,S-acetals or ammonium dithiocarbamate to afford dithiane, oxazine or pyrazolodithiocarbamate derivatives 25–29, respectively. Chemoselective cyclization of compound 29 with H₂SO₄, NaOH or MeI gave compounds 30–32, respectively. Benzopyrano derivatives 34,36 were obtained through the reaction of compound 1 with a mixture of thiourea, triethyl orthoformate and ethyl cyanoacetate or with cyanoketene S,S diacetals, respectively.     

Lanostane triterpenoids from cultivated fruiting bodies of the basidiomycete Ganoderma australe

A new lanostane triterpene (1), together with three known compounds (2–4), were isolated from cultivated fruiting bodies of the basidiomycete Ganoderma australe. The structure was elucidated on the basis of NMR spectroscopic and mass spectrometry data. The olefinic geometry of methyl australate (2) was revised from 20(22)Z to 20(22)E. These compounds (1–4) were different from the lanostanes isolated from mycelial cultures of the same strain source.     

A new caffeic acid tetramer from the Dracocephalum moldavica L.

A new caffeic acid tetramer compound, named (+) methyl rabdosiin (4), together with seven known caffeic acid multimers (1–3, 5–8) and one caffeic acid monomer (9), were isolated from the aerial parts of Dracocephalum moldavica L. The structures of these compounds were assigned on the basis of 1D and 2D NMR spectroscopic and mass spectrometry analyses. The protective effects of compounds 2–4 against hydrogen peroxide (H₂O₂)-induced apoptosis were evaluated in primary cardiomyocytes of SD neonatal rats in vitro by the MTT method. Three compounds exhibited potent protective activities at 12.5 μg/mL.     

New red-luminescent cadmium coordination polymers with 4-amino-2,1,3-benzothiadiazole

New polymeric cadmium complexes, α-[CdLCl₂]_n (1), [CdL₂Cl₂]_n (2) and β-[CdLCl₂]_n (3) (L = 4-amino-2,1,3-benzothiadiazole), were obtained as products of the reaction of CdCl₂ with L. The synthetic procedures allowing isolation of pure 1–3 were optimized. The structures of 1–3 were established by single-crystal X-ray diffraction and the compounds were characterized by UV–Vis and IR spectroscopy. In these compounds, L is either μ-bridging (1) or terminal (2 and 3). The UV–Vis spectra of the complexes in the solid state resemble that of free L. However, coordination of L leads to a significant shift of emission in photoluminescence spectra from yellow (free L) to red (1–3).     

Synthesis and antibacterial evaluation of fused pyrazoles and Schiff bases

Abstract

For the discovery of new antibiotic drugs to face the problem of microbial resistance, a series of fused pyrazoles such as pyrazolopyrimidines 15a–f, pyrazoloquinazolines 18a, b and pyrazolotriazines 20a, b was synthesized via the reaction of 5-aminopyrazoles 8a, b with 3-(dimethylamino)-1-aryl-prop-2-en-1-ones 9a–d, 2-((dimethylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione (16) and sodium nitrite (NaNO₂), respectively. Finally, Schiff bases 22a–g were obtained by the condensation of 8a, b with aromatic aldehydes 21a–d. The chemical structure of the new compounds was confirmed by spectroscopy. The structure of 15?b was confirmed by X-ray crystallography analysis. All compounds were screened for antibacterial properties toward multi-drug resistant bacteria (MDRB).     

Bioactive furanocoumarins from the stems and leaves of Clausena hainanensis

A new furanocoumarin, clauhainanin A (1), together with seven known furanocoumarins (2–8), were isolated from the stems and leaves of Clausena hainanensis. The structure of 1 was elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with data reported in the literature. All known compounds (2–8) were isolated from C. hainanensis for the first time. All isolated compounds were evaluated for their cytotoxicities against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 in vitro. Compounds 1–8 exhibited significant inhibitory effects with IC₅₀ values ranging from 1.36 to 18.96 μM.     

Two new triterpenoid glycosides from the stems of Camellia oleifera Abel

Two new oleanane-type triterpenoid glycosides, 3-O-β-D-xylopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→3)-[β-D-glucuronopyranosyl-(1→2)]-β-D-glucuronopyranosyl-22α-angeloyloxyolean-12-ene-15α,16α,28-triol(1) and 3-O-β-D-xylopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→3)-[β-D-glucuronopyranosyl-(1→2)]-β-D-glucuronopyranosyl-21β-acetyl-22α-angeloyloxyolean-12-ene-16α,28-diol (2) were isolated from the stems of Camellia oleifera Abel. Their structures were elucidated by means of spectroscopic methods and chemical evidence. The cytotoxic activities of compounds 1–2 were evaluated against five human tumour cell lines (HCT-8, BGC-823, A5049, and A2780). Compounds 1–2 showed cytotoxic activity against five human cancer cell lines, with IC₅₀ values ranging from 3.15 to 7.32 μM.     

Two new triterpenoids from the fungus Diplodia cupressi

Abstract

One new pentanortriterpenoid, 23,24,25,26,27-pentanorlanost-7,9(11)-dien-3β,22-diol (1), one new triterpenoid, lanost-8-en-3β,22S,23S-triol (2), together with the known triterpenoid, 23,24,25,26,27-pentanorlanost-8-en-3β,22-diol (3), were obtained from culture of the fungus Diplodia cupressi associated with the moss Polytrichum commune. The structures of the new compounds were elucidated by extensive spectroscopic techniques including HR-ESIMS and 1?D and 2?D NMR experiments. The cytotoxicity of these compounds against human cancer cell lines (A549, Hep G2, Hepa 1c1c7, and Hela) was evaluated and compound 2 exhibited weak inhibitory activity with IC₅₀ value of 35.0?±?2.3?μM against the proliferation of the Hepa 1c1c7 cells.     

Two new 5,6-epoxysterols from calcareous marine sponge Leucetta chagosensis

Chemical investigation on CH₂Cl₂ extract of the marine sponge Leucetta chagosensis, collected from the South China Sea, afforded two new 5,6-epoxysterols, 5α,6α-epoxycholesta-8(14),22(E)-diene-3β,7α-diol (1) and (24R)-24-ethyl-5α,6α-epoxycholesta-8(14),22(E)-diene-3β,7α-diol (2) along with ten known related steroid analogs (3–12). Their structures were elucidated on the basis of NMR spectroscopic analyses, and comparison with the literature. All isolates were tested for cytotoxicity against three tumor cell lines only known compounds 11 and 12 exhibited notable cytotoxic activity against A549 (IC₅₀: 3.0 and 5.6?μM), PC9 (2.0 and 15.6?μM), and MCF-7 (9.4 and 11.8?μM) cell lines, respectively.     

Synthesis,antioxidant and antitumor activities of some of new cyclobutane containing triazoles derivatives

Abstract

Thiosemicarbazides (2a–e) were obtained by the interaction of furan-2-carboxylic acid hydrazide (1) with five different isothiocyanate (RNCS) derivatives. By addition of KOH to the reaction medium, ethyl, allyl, phenyl and benzyl, p-tolyl substituted 1,2,4-triazoles (3a–e) were obtained. 3a–e were dissolved in dry acetone containing K₂CO₃ in the presence of 2-chloro-1-(3-methyl-3-mesitylcyclobutyl) ethanone (4) to give 3,4,5-trisubstituted 1,2,4-triazole sulfanyl compounds containing a cyclobutane ring (5a–e). The structures of the final compounds were confirmed by elemental analyses, FT-IR, ¹H-NMR and ¹³C-NMR. The antioxidant and antitumor properties of the synthesized compounds were also investigated. Three of the triazole derivatives with p-tolyl, benzyl and phenyl substituents (5c–e) displayed good antioxidant and antitumor activity in comparison to the standards.     

Chemical constituents,cytotoxic and antioxidant activities of extract from the rhizomes of Osmunda japonica Thunb

Abstract

Thirty-three compounds (1–33) were isolated from the rhizomes of Osmunda japonica. Their structures were elucidated on the basis of spectral analysis and identified as ent-kaurene terpenoids (1–3), anthraquinones (4–8), flavonoids (9–12), steroids (13–15), and other compounds (16–33). Compound 1–14, 19–27 were isolated from the genus osmunda for the first time. Compound 28–29 were isolated from the plant for the first time. Cytotoxicities of all compounds against Hela, HepG2 and A549 cell lines were measured by MTT assay, and their antioxidant activities were determined by DPPH and ABTS radical scavenging assays. Compound 2 exhibited potent cytotoxicity against Hela, HepG2 cell lines with IC₅₀ values of 9.31 and 9.66?μM, respectively. Compound 9 showed good antioxidant activity. The Trolox-equivalent antioxidant capacity (TEAC) value was 0.95?mM in ABTS assay, and the IC₅₀ value was 18.63?μM in DPPH assay.