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.     

Two New Compounds Isolated from<em> Liriope muscari</em>

Two new compounds, (2S,3R)-methyl 7-hydroxy-2-(4-hydroxy-3-methoxy-phenyl)-3-(hydroxymethyl)-2,3-dihydrobenzofuran-5-carboxylate (1) and (4R,5S)-5-(3-hydroxy-2,6-dimethylphenyl)-4-isopropyldihydrofuran-2-one (2), tentatively named norcurlignan and limlactone, respectively, were isolated from Liriope muscari, together with the known compound (-)-pinoresinol (3). The structures of these compounds were elucidated and characterized on the basis of 1D NMR, 2D NMR, CD and MS data. The in vitro antioxidant activities of compounds 1-3 were assessed by the DPPH and ABTS scavenging methods.     

Constituents from Bupleurum montanum (Coss. & Dur.) (Apiaceae)

A chemical investigation of the aerial parts of Bupleurum montanum (Coss. & Dur.) (Apiaceae) afforded five compounds, quercitin 1, tamarexetin 2, isorhamnetin-3-rutinoside 3, kaempferol-3-O-β-rutinoside 4, and 3,4-dihydroxybenzoic acid (Protocatechuic acid) 5. The structural elucidation was performed mainly by MS, 1D and 2D NMR spectrum data.     

A new isoflavane from processed Astragalus membranaceus

A new isoflavane named astraganoside,together with five known compounds had been isolated from the processed Astragralus membranaceus.The structure of the novel compound was elucidated as(3R,4R)-3-(2-hydroxy-3,4-dimethoxyphenyl)chroman- 4,7-diol-7-O-β-D-glucopyranoside(1)based on spectroscopic methods including UV,IR,ESI-MS,1D NMR and 2D NMR techniques.     

A novel dimeric diarylheptanoid from the rhizomes of Alpinia officinarum

A novel dimeric diarylheptanoid,named alpinin A(1),along with two known compounds,1,7-diphenyl-5-ol-3-heptanone and 7- (4’-hydroxy-3’-methoxyphenyl)-l-phenyl-4-heptene-3-one,were isolated from the rhizomes of Alpinia officinarum Hance.The structure of compound 1 was elucidated on the basis of spectral analysis,including HR-IT-TOF-MS,1D and 2D NMR.And a possible biogenetic pathway had been proposed for 1.     

Synthesis of mono- and dihydroxy-substituted 2-aminocyclooctanecarboxylic acid enantiomers

(1R,2S,6R)-2-Amino-6-hydroxycyclooctanecarboxylic acid (?)-10 was synthesized from (1R,2S)-2-aminocyclooct-5-enecarboxylic acid (+)-2 via an iodolactone intermediate, while (1R,2S,3R,4S)-2-amino-5,6-dihydroxycyclooctanecarboxylic acid (?)-12 was prepared by using the OsO₄-catalyzed oxidation of Boc-protected amino ester (?)-5. The stereochemistry and relative configurations of the synthesized compounds were determined by 1D and 2D NMR spectroscopy (based on 2D NOE cross-peaks and ³J(H,H) coupling constants) and X-ray crystallography.     

A new eudesmane sesquiterpene glycoside from Parepigynum funingense

A new eudesmane sesquiterpene glycoside,1α,6β-dihydroxy-5,10-bis-epi-eudesm-4(15)-ene-6-O-β-D-glucopyranoside(2), together with a known analogue compound,1α,6β-dihydroxy-5,10-bis-epi-eudesm-3-ene-6-O-β-D-glucopyranoside(1),were isolated from the roots of Parepigynumfuningense.The structure of 2 was determined by 1D and 2D NMR spectroscopy.Compound 1 was isolated from this plant for the first time.     

Three new eudesmane sesquiterpenes from Artemisia vestita

Three eudesmane sesquiterpene lactones,namely artemivestinolides A–C(1–3),along with three known 11-epimeric lactones(4–6),were isolated from the aerial parts of Artemisia vestita.Their structures were elucidated on the basis of extensive spectroscopic analyses(IR,HR-ESIMS,1D NMR and 2D NMR),and the absolute confgurations were determined by single-crystal X-ray diffraction(with copper radiation).Furthermore,in an in vitro assay,the three new compounds exhibited a moderate inhibition of the lipopolysaccharide(LPS)-induced nitric oxide(NO)production in BV-2 microglial cells.     

A novel bacteriohopanoid from Celtis australis L.bark

A novel bacteriohopanoid elucidated as 3β-hydroxy-35-(cyclohexyl-5’-propan-7’-one)-33-ethyl-34-methyl-bactereohopane(1) has been isolated from the bark of Celtis australis(Ulmaceae) together with three known compounds apigenin,quercetin and its glucoside.The structure of 1 was characterized by means of chemical and spectral methods including advanced 2D NMR studies.     

New azaphilones from Chaetomium globosum isolated from the built environment

A strain of Chaetomium globosum (DAOM 240359) was isolated from an indoor air sample in Ottawa, Ontario, Canada. When fermented in liquid culture, this strain produced a number of known metabolites including chaetoglobosins A (6), C, and F (7), chaetomugilin D (5), chaetoviridin A (4), and three new nitrogenous azaphilones; 4′-epi-N-2-hydroxyethyl-azachaetoviridin A (1), N-2-butyric-azochaetoviridin E (2), and isochromophilone XIII (3). The structures were elucidated by spectroscopic analysis including; HRMS, 1D and 2D NMR, UV, and ORD. Compounds 2–7 were antimicrobial when tested using quantitative growth inhibition assays.     

Synthesis,characterization and ethylene polymerization of 1-(2,6-dimethyl-4-fluorenylphenylimino)-2-aryliminoacenaphthylnickel bromides

A series of 1-(2,6-dimethyl-4-fluorenylphenylimino)-2-aryliminoacenaphthylene compounds (aryl = 2,6-di(Me)Ph (L1), 2,6-di(Et)Ph (L2), 2,6-di(i-Pr)Ph (L3), 2,4,6-tri(Me)Ph (L4), 2,6-di(Et)-4-MePh (L5)) was prepared and used to form their corresponding dibromonickel complexes (D1–D5). Both L1–L5 and D1–D5 were fully characterized by FT-IR and elemental analysis as well as NMR measurements in the case of ligands L1–L5. The molecular structure of the representative complex D5 was confirmed by single crystal X-ray diffraction revealing a distorted trigonal bipyramidal geometry around the nickel center. On activation with either ethylaluminium sesquichloride (Et₃Al₂Cl₃, EASC) or methylaluminoxane (MAO), all nickel complexes exhibited high activities up to 9.82 × 10⁶ g of PE (mol of Ni)⁻¹ h⁻¹ for ethylene polymerization. In comparison with the polyethylenes obtained with related Ni pre-catalysts, the polyethylenes obtained in this work possessed relatively higher molecular weights and lower levels of branching, highlighting the significant influence of the remote fluorenyl substituent.     

Bioactive compounds from Selaginella involven Spring that protect PC-12 cells

Two new compounds named as 3b 12 16-trihydroxy-6 8 11 13-abietatrien（1） （8R 80S）-4 40 8-trihydroxyl-3 30-dimethoxyl-90-lignanolide（2） and a new natural product 4 40-dihydroxyl-3 30 5 50-dimethoxyldiphenyl diketone（3） were isolated from the whole herbs of Selaginella involven Spring.The structures were elucidated by spectroscopic analyses including UV,IR,1D,2D NMR and MS methods.Additionally,these three compounds exhibited potent protective effect against the injury of PC-12 cells induced by hypoxia/reoxygenation.     

Two new isoflavonoids from the rhizomes of Belamcanda chinensis

Two new isoflavonoids, 6-methoxy-5,7,8,4'-tetrahydryoxyisoflavone (1) and 4'-methoxy -5,6-dihydroxyisoflavone-7-O-β-D-glucopyranoside (2), were isolated from the rhizomes of Belamcanda chinensis (L.) DC. Their structures were elucidated by extensive spectroscopic evidence including ID NMR, 2D NMR, MS and IR spectra.     

New steroidal sapogenins from the acid hydrolysis product of the whole glycoside mixture of Welsh onion seeds

Two new steroidal sapogenins(1,2) along with five known steroidal sapogenins were isolated from the acid hydrolysis product of the whole glycoside mixture of Welsh onion(Allium fistulosum L.) seeds.Based on comprehensive spectroscopic analyses, including 2D NMR spectroscopy and mass spectrometry,their structures were elucidated as(25R)-19-norspirosta-l,3,5(10)-triene-4 -methyl-2-ol(1),(25R)-spirost-l,4-diene-3-one-2,6-diol(2),(25R)-spirost-l,4-diene-3-one-2-ol(3),(25R)-spirost-4-ene-3-one-2-ol (4),yuccagenin(5),gitogenin(6) and tigogenin(7).     

N-[2-(1H-吲哚-3)乙基]-2-乙酰噻唑-4-甲酰胺及其类似物的合成

N-[2-(1H-吲哚-3)乙基]-2-乙酰噻唑-4-甲酰胺是最近从海洋细菌中分离得到的一种新型的天然杀藻剂, 以D-丙氨酸为原料合成了该化合物, 并用类似的方法首次合成了它的类似物2, 3和4. 其关键步骤为通过将取代的4-噻唑甲酸制成混酐与色胺连接的偶联反应. 各中间体都通过¹H NMR和¹³C NMR得到证实. 最终产品通过¹H NMR, ¹³C NMR和HRMS证实, 与文献所报道相一致.     

Stereoselective enzymatic synthesis of monoglucosyl-myo-inositols with in vivo anti-inflammatory activity

The monoglucosyl-inositols α-d-glucopyranosyl-(1→4)-4d-myo-inositol 3 and α-d-glucopyranosyl-(1→1)-1d-myo-inositol 4 were synthesized by a combined enzymatic transglucosylation and hydrolysis strategy, using cyclodextrin glucosyl transferase (CGTase) from Thermoanaerobacter sp., followed by hydrolysis with Aspergillus niger glucoamylase. The glucosides were separated by preparative HPLC and fully characterized by extensive 1D and 2D NMR studies. The structure of the regioisomer 4 was confirmed by X-ray crystallography of its perbenzoylated derivative 4a. Both isomers demonstrated in vivo anti-inflammatory activity at comparative levels to corticosterone on mouse ear oedema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) and in rat hind paw oedema induced by carrageenan.     

Trefoil-shaped metallacycle and metallacage via heteroleptic self-assembly

Template-oriented multi-component synthesis method has been proven to be an exceedingly reasonable and excellent method for the synthesis of giant two-dimensional (2D) and three-dimensional (3D) supramolecules, but designing and constructing heteroleptic and controllable self-assembly without unexpected by-products remains a challenge. Here we report two discrete trefoil-shaped metallacycle S1 and metallacage S2 by heteroleptic self-assembly using one hexaphenylbenzene core ligand and two capping ligands. The 2D trefoil-shaped metallacycle S1 could resemble the emblem of the classic ‘Mitsubishi’ motif. The use of template-oriented ligand and bent spacer ligand promotes the quantitative formation of the desired 3D trefoil-shaped metallacage S2. The formed metallacage S2 possesses a molecular weight up to 36 kDa, diameter 6.6 nm and height 3.0 nm. All supramolecular coordination complexes were fully characterized by NMR spectroscopy (¹H NMR, 2D COSY, 2D NOESY, 2D DOSY), high-resolution electrospray ionization mass spectrometry ESI-MS, ESI-TWIM-MS, TEM and AFM.     

Pimprinols A–C,from the terrestrial actinomycete,Streptomyces sp.

A Streptomyces sp. Lv3-13, isolated from the rhizosphere soil of the plant Mespilus germanica, has yielded three new pimprinine derivatives, named pimprinols A–C (1–3) and the unknown (2-aminophenyl)(2-ethyloxazol-5-yl) methanone (4) along with the known compounds 2-ethyl oxazole pimprinine and 2-propyl oxazole pimprinine. The structures of the compounds were elucidated based on spectroscopic methods including UV, HR-ESIMS and 1D, 2D NMR data. Compounds 1–4 were screened for antimicrobial and cytotoxic activities.     

Chiral solvating properties of (S)-1-benzyl-6-methylpiperazine-2,5-dione

In CDCl₃ solution, enantiopure (S)-1-benzyl-6-methylpiperazine-2,5-dione (S)-1a formed diastereomeric CO⋯H–N hydrogen-bonded associates with racemic (RS,Z)-1-benzyl-3-[(dimethylamino)methylidene]piperazine-2,5-diones 2a and 2b, (RS)-tert-butyl pyroglutamate (RS)-2c and (RS)-N-benzoylalanine methyl ester (RS)-2d. This resulted in splitting (doubling) of the characteristic signals in the ¹H NMR and ¹³C spectra of racemic compounds 2a–d in the presence of 1 equiv of (S)-1a. The formation of hydrogen-bonded dimers in CDCl₃ solution was studied by ¹H NMR, ¹³C NMR and 2D NMR and confirmed by the intermolecular NOE observed between the hydrogen-bonded amide protons from each of the monomeric units, (S)-1a and 2a–c. On the other hand, a slightly different binding mode was proposed for association of (S)-1a with alaninamide (RS)-2d. Enantiomer compositions of known (weighed) mixtures of both enantiomers of tert-butyl pyroglutamate 2c were re-determined by ¹H NMR in the presence of (S)-1a in CDCl₃. The experimental values were in good agreement with the theoretical values, thus indicating the potential applicability of (S)-1a and related diketopiperazines as chiral solvating agents in NMR spectroscopy.     

Two new ent-kaurane diterpenoids from the aerial parts of Isodon excisoides简

Two new ent-kaurane diterpenoids, ent-7a,14b-dihydroxykaur-16-en-15-one-20-oic acid(1) and 1,7a,12b,14b-tetrahydroxy-1,10-seco-ent-kaur-10,16-dien-15-one(2), together with six known ones(3–8), were isolated from the EtOAc extract of the aerial parts of Isodon excisoides. Their structures were elucidated on the basis of 1D NMR and 2D NMR analyses as well as HR-ESI-MS experiments.