2D CD Research Articles

Three new quassinoids isolated from the wood of Picrasma javanica and their anti-Vpr activities.

Three new quassinoids, javanicinols A and B (1 and 2) and 4-keto-(16S)-methoxyjavanicin B (3), together with three known quassinoids (4-6) were isolated from the chloroform-soluble fraction of the methanol extract of the Picrasma javanica wood. The structures of 1-3 were determined by spectroscopic analyses, including 1D and 2D NMR, HRESIMS, and CD. The anti-HIV-1 viral protein R (Vpr) assay revealed that 1 and 2 exhibited potent anti-Vpr activities at 1.25μM. Furthermore, the assay also revealed the potent anti-Vpr activities of (16R)-methoxyjavanicin B (7) and (16S)-methoxyjavanicin B (8), which were previously isolated from the Picrasma javanica wood.

Imidazole Multi-Carboxylate-Based 2D Cd(II) MOF: Preparation, Crystal Structure, and Properties

By adopting one imidazole multi-carboxylate ligand, 2-(3-carboxylphenyl)-1H-imidazole-4,5-dicarboxylic acid (m-CPhH4IDC) and one N-containg ligand, 2,2′-bipyridine (2,2′-Bipy) to react with Cd(NO3)2, under solvothermal condition, a two-dimensional metal-organic framework, {[Cd6(m-CPhHIDC)4(2,2′-Bipy)6] · 4H2O}n (I) has been sucessfully constructed. The structure has been determined by single-crystal X-ray diffraction analysis (CIF files CCDC no. 1480230) and further characterized by elemental analyses, IR spectra, and thermogravimetric analysis. MOF I exhibits a rare (3,4)-connected 2D structure bearing two kinds of organic ligands. According to the crystal data, the coordination ability and mode of the imidazole multi-carboxylate ligand are discussed. Furthermore, the thermal stability and solid-state photoluminescent properties of MOF I have been investigated.

Synthesis, Structure and Luminescent Property of a 3D Layered-Pillared Cd(II) Metal–Organic Framework Derived from Mixed Rigid and Flexible Ligands

A new 3D Cd(II) metal–organic framework of [Cd2(HIDC)2(bibp)1.5]n (1) was synthesized hydrothermally by the reaction of imidazole-4,5-dicarboxylic acid (H2IDC) and 4,4′-bis(imidazol-1-ylmethyl)biphenyl (bibp) with Cd(NO3)2·4H2O. Single-crystal X-ray diffraction analysis reveals that this compound crystallizes in triclinic, space group Pī with a = 9.6610(3), b = 15.5866(5), c = 16.0228(6) Ǻ, α = 110.662(3), β = 101.521(3), γ = 107.115(3)˚, V = 2029.46(15) Ǻ3, Z = 2, Dc = 1.644 g cm−3, µ = 1.113 mm−1, F(000) = 1002, the final R1 = 0.0468 and wR2 = 0.0962 for 8932 observed reflections with I > 2σ(I). In 1, the alternately interconnection of Cd(II) ions by µ2-HIDC2− and µ3-HIDC2− anions resulted in the formation of 1D [Cd2(µ2-HIDC)(µ3-HIDC)]∞ with the right- and left-helical chains, which were further linked by the oxygen atoms derived from one of the carboxylate groups of µ3-HIDC2− anions, generating the 1D double helical chain structure of [Cd4(µ2-HIDC)2(µ3-HIDC)2]∞ along a axis. These adjacent 1D double chains are further linked by cis-µ2-bibp ligands to form a 2D network structure of [Cd4(µ2-HIDC)2(µ3-HIDC)2(cis-µ2-bibp)2]n, which are further pillared by trans-µ2-bibp ligands to generate a 3D layered-pillared metal–organic framework architecture of [Cd4(µ2-HIDC)2(µ3-HIDC)2(cis-µ2-bibp)2(trans-µ2-bibp)]n. Furthermore, the thermal stability and luminescent property of 1 have also been investigated. A 3D Cd(II) layered-pillared metal–organic framework was synthesized hydrothermally. This new compound displays high thermal stability and intense fluorescent emission.

Construction of a dual-response luminescent metal-organic framework with excellent stability for detecting Fe3+ and antibiotic with high selectivity and sensitivity

A 3D Cd(II)-based MOF, [Cd4(L)4·H2O·EtOH]n, was successfully constructed by the hydrothermal synthesis and detailly characterized by various methods. The as-made sample not only has excellent water stability but also possesses obvious a luminescent property, leading to that it can be considered as a potentially dual-response luminescent sensor for detecting Fe3+ and antibiotics in water. It is obviously found that the resultant sample has the high sensitive and selectivity for monitoring Fe3+ and NFT in aqueous solution. More importantly, this sensing material owns the excellent recyclability at least seven times.

Reversible Dynamic Structural Transformation between 3D and 1D Cd–Co Heterometallic MOFs Showing Switchable Spin-Canted Antiferromagnetism

Two Cd-Co heterometallic frameworks based on the ligand methylenesuccinate acid (H2MSA), three-dimensional (3D) [CdCo6(MSA)6(μ3-OH)2(H2O)2]·H2O (1) and one-dimensional (1D) [CdCo(MSA)2(H2O)5]·3H2O ...

Synthesis, structure and properties of a one-dimensional Cd(II) complex based on a chiral ligand

A new 1D Cd(II) complex [Cd(L-pheA)(Ac)]n (1) where the L-pheA– anion stands for the chiral ligand (L-phenylalanine hydroxamic acid) is synthesized and characterized. The single crystal X-ray analysis reveals that each Cd(II) atom is coordinated by three L-pheA– ligands and two acetate anions in a distorted seven-coordinated pentagonal bipyramidal configuration. By the interactions of two N—H⋯O and one N—H⋯N hydrogen bonds a 2D supramolecular network is formed. The solid-state luminescent properties of complex 1 are observed.

Template effect of innocent and coordinating anions on the formation of interpenetrated 2D and 3D networks: methyl orange and iodine sorption studies

A pyridyl based Schiff base resulted in a 2D staircase network (CP1) with Cd(ii) when ClO4− is the counter anion while the use of benzene-1,3-disulphonate counter anion resulted in a novel 3D Cd(ii) coordination polymer with threefold interpenetration (CP2).

Structural variability and photoluminescence properties of four neoteric 3D Cd(II) coordination polymers based on semirigid Bis(Thiazolylbenzimidazole) and different types of carboxylic acid linkers

Four Cd(II) coordination complexes, formulated as [Cd(dbim)0.5(H2oba)]n (1), [Cd(dbim)(m-H2ada)]n (2), [Cd2(dbim)(1,2,4-H3btc)1.5]n (3) and [Cd(dbim)(H2sdba)]n (4), (dbim = 1-(4-((2,5-dimethyl-3aH-benzo[d]imidazole-1(7aH)-yl)methyl)benzyl)-3a,7a-dihydro-2,5-dimethyl-1H-benzo[d]imidazole, H2oba = 4,4′-oxybis(benzoic acid), m-H2ada = 1,3-adamantanediacetic acid, 1,2,4-H3btc = 1,2,4-Benzenetricarboxylic acid, H2sdba = 4,4′-sulfonyldibenzoic acid), have been prepared by hydrothermal reactions. Complex 1 reveal a 2-fold interpenetrating 3D frameworks with (412·63)-pcu topology. 2 display a 3-fold interpenetrating 3D frameworks with 63-dia Diamond topology. 3 exhibit a (3,6)-connected 3D topology net with point symbol of (42·610·72·8)(42·6). 4 is a 3D framework with a point symbol of (65·8). The structural comparison of complexes 1–4 shows that the final frameworks can be tuned by various carboxylate coligands and dbim ligand with changeable conformations. Moreover, thermal stability and photoluminescent properties of complexes 1–4 have also been investigated.

Influence of Process Variables on Morphology and Field Emission Properties of Aligned 2D Cd(OH)2 Nanosheets

Influence of Process Variables on Morphology and Field Emission Properties of Aligned 2D Cd(OH)₂ Nanosheets

A ciprofloxacin based 1D Cd(II) coordination polymer with highly efficient humidity sensing performance

Coordination polymers (CPs) have recently be considered as promising candidates for electrical sensors, especially impedimetric ones, yet still limited by low sensitivity, slow response, and large humidity hysteresis. In this contribution, {[Cd0.5(cfH)(4, 4′-bpy)0.5](NO3)·H2O}n (named as CdL, cfH = ciprofloxacin, 4,4′-bpy = 4,4′-bipyridine) has been synthesized via a facile solvent evaporation method at room temperature. The CdL CP possesses a one dimensional (1D) structure that is further connected by hydrogen bonds forming a three dimensional (3D) supramolecular network. Taking into account of rich hydrogen bonds and uncoordinated atoms (N, O, and F), the CdL CP was assembled into an impedimetric sensor and thus the humidity sensing performance was investigated systemically. The CdL based sensor exhibited good humidity sensing performance in a wide humidity range, including high sensitivity, small hysteresis, and relatively rapid response–recovery. Moreover, the sensing mechanism was discussed by complex impedance analysis in detail, so as to confirm the charge carrier contribution at different relative humidity (RH) range. These results indicate the potential application of CdL in humidity sensors, and further reveal the promising prospects for construction of CP-based electrical sensory devices.

Pterocaullins A−D, four sesquiterpene lactones from Inula pterocaula

Four new sesquiterpenes, pterocaullins A−D (1−4), along with ten known compounds were isolated from the whole plants of Inula pterocaula. Structures of new compounds were elucidated by the combined use of HRESIMS, 1D and 2D NMR and CD spectroscopic methods. The absolute structures of 1 and 2 were further confirmed by Cu Kα X-ray crystallographic analyses. In addition, all isolated compounds were tested for their inhibitory effects against LPS-induced NO production in RAW 264.7 macrophages. Pterocaullin B displayed potential anti-inflammatory activity with IC50 value of 7.03 μM.

Chemical constituents from the stems of Securidaca inappendiculata Hassk

Three new neolignan glycosides, (7R,8S)-4-hydroxy-3,3′-dimethoxy-8,4′-oxyneoligna-7,9,9′-triol-4-O-β-d-glucopyranosyl-(1 → 4)-β-D-glucopyranoside (1), (7R,8S)-4-hydroxy-3,5′-dimethoxy-4′,7-epoxy-8,3′-neoligna-9,9′-diol-9’-O-β-d-glucopyranosyl-4-O-[β-d-glucopyranosyl-(1 → 4)]-β-D-glucopyranoside (2), and (7R,8S)-4-hydroxy-3,5,5′-trimethoxy-4′,7-epoxy-8,3′-neoligna-9,9′-diol-9’-O-β-d-glucopyranosyl-4-O-[β-d-glucopyranosyl-(1 → 4)]-β-D-glucopyranoside (3), one new phenolic glycoside, securiphenoside B (4) and two new hemiterpene glycosides, securiterpenoside E-F (5–6) were isolated from the stems of Securidaca inappendiculata Hassk. Their structures were elucidated on the basis of 1D and 2D NMR, HRESIMS, CD and chemical evidence. Furthermore, compound 2 showed moderate hepatoprotective activity compared with bicyclol in vitro.

Bioactive cembrane-type diterpenoids from the gum-resin of Boswellia carterii

Chemical examination of the gum-resin of Boswellia carterii resulted in the isolation and characterization of eighteen new cembrane-type diterpenoids, named as Boscartins P-AG (1–18) and eight known ones. Their structures were established on the basis of extensive spectroscopic (2D NMR, IR, CD, MS and X-ray) analysis in combination with modified Mosher’s method. All compounds featured unusual 1,12-oxygenated tetrahydrofuran functionalities, and were evaluated for hepatoprotective activity against D-galactosamine-induced HL-7702 cell damage and cytotoxic activity against MCF-7 human breast cancer cell in vitro. Compounds 1, 6–10, 12–13, 16–17 and 21–25 (10 μM) showed some hepatoprotective activity against D-galactosamine-induced HL-7702 cell damage.

Two Zinc(II)/Cadmium(II) Coordination Polymers Constructed by Semirigid Carboxylic Acid Ligand: Syntheses, Structures, and Photoluminescence Properties

Two new coordination polymers {[Zn(HL)(HBpp)] · H2O}n (I) and [Cd(HL)(HBpe)]n (II) (H4L = 5-(2,3-dicarboxy phenoxy) isophthalic acid, Bpp = 1,3-bis(4-pyridyl)propane, Bpe = 1,2-bis(4-pyridyl)ethylene) were prepared and characterize by element analysis, powder XRD and single crystal X-ray diffraction (CCDC nos. 1836060 (I), 1844999 (II)). The single-crystal X-ray diffractions reveal that the complex I is a 2D carboxylate layer with the HBpp suspension arms, in which the zinc(II) is four-coordinated with a tetrahedral geometry. Compound II is a 1D Cd(II)-carboxylate chains, in which the cadmium(II) is seven-coordinated with a distorted pentagonal bipyramidal geometry. Complexes I and II are further extended into three-dimensional supramolecular framework via hydrogen bonds. The solid state luminescent properties of compounds I and II have been investigated.

Two new diarylheptanoids from the green husks of Juglans regia L. and their cytotoxic activities

Two new diarylheptanoids, 3- hydroxy- 3′,4″- epoxy- 1- (4′- methoxyphenyl) - 7- (3″- hydroxylphenyl)– heptane (1) and 2,3- dihydroxy- 1- (4′- hydroxy- 3′- methoxyphenyl)- 7- (4″- hydroxyphenyl)– heptanes (2), along with two known compounds, JuglaninB (3) and 4,17- dimethoxy- 2- oxatricyclo [13.2.2.13,7] eicosa- 3,5,7 (20),15,17,18- hexaene- 10,16- diol (4), were isolated from the green husks of Juglans regia L. Their structures were elucidated using1D and 2D NMR spectroscopic methods, HRESIMS, and CD spectra. Against MCF-7, compounds 1–4 have moderate cytotoxic activity, ranging from 11.4–32.7 μg · mL−1, compared with 31.9 μg · mL−1 forthe positive control cisplatin.

New cytotoxic biflavones from Selaginella doederleinii

Three new biflavones, apigenin-(3′,8″)-chrysin (1), (2S)-2,3-Dihydroametoflavone 5,4′-dimethyl ether (2), and (2S)-5″,7″-Dihydroxy-2″-phenoxychromonyl-(4′″,3′)-naringenin (3), together with seven known biflavones (4–10) were isolated from the 75% EtOH extract of Selaginella doederleinii. The structures of new compounds were established by application of spectroscopic methods, including 1D and 2D NMR, HRMS, and CD measurements. In addition, all new compounds were evaluated for their cytotoxic potential against three human cancer cell lines A549, MCF-7, and SMMC-7721 in vitro. Compound 2 exhibited potent cytotoxic activity with IC50 values ranging from 6.35 to 10.18 μM.

Six new monacolin analogs from red yeast rice.

Six novel monacolin analogs, monacolins V1-V6 (1-6), together with seven known ones (7-13), were isolated from the ethyl acetate extract of red yeast rice. Their structures and absolute configurations were determined by spectroscopic methods, especially 2D NMR (1H-1HCOSY, HSQC, HMBC, and NOESY/ROESY) and CD spectroscopic analyses as well as chemical derivation. Monacolins V2 (2) and V3 (3) represent the first examples of monacolins with 3-hydroxybutyrate substitute. The anti-inflammatory inhibitory activities against the lipopolysaccharide (LPS) induced NO production in BV-2 cells as well as antioxidant activities against rat liver microsomal lipid peroxidation were evaluated.

New acetylenic compounds and lignans from Dolomiaea berardioidea (Franch.) Shih

Two new acetylenic compounds (1 and 2), two new lignans (3 and 4) along with eight known lignans (5−12), ten known terpenoids (13−22) and one known aromatic compound (23) were isolated from the whole plants of Dolomiaea berardioidea (Franch.) Shih. Structures of new compounds were elucidated by combined use of HRESIMS, 1D and 2D NMR and CD spectroscopic methods. The absolute structures of 1 and 3 were further confirmed by Cu Kα X-ray crystallographic analyses. In addition, all isolated compounds were also tested for their inhibitory effects against LPS-induced NO production of RAW 264.7 macrophage. Compound 22 displayed potential anti-inflammatory activity with IC50 value of 7.4 μM.

New lignan glycosides from the stems of Securidaca inappendiculata Hassk

Three new lignan glycosides, (7R,8S)-4-hydroxy-3,5′-dimethoxy-4′,7-epoxy-8,3′-neoligna-9,9′-diol-4-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (1), (7S,8R)-4-hydroxy-3,5,5′-trimethoxy-4′,7-epoxy-8,3′-neoligna-9,9′-diol-4-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (2) and (7S,7′S,8R,8′R)-4,4′-dihydroxy-3,5,3′,5′-tetramethoxy-7,9′:7′,9-diepoxylignane-4-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (3) were isolated from the stems of Securidaca inappendiculata Hassk. Their structures were elucidated on the basis of spectroscopic analyses, including 1D and 2D NMR, HRESIMS, CD and chemical evidence. The MTT assay showed that compounds 1-3 exhibited moderate hepatoprotective activities against acetaminophen-induced HepG2 cell injury at respective 10 μM concentrations (Bicyclol as positive contrast).

Secondary metabolites from the leaves of Juglans regia L.

One new diarylheptanoid (1) and one previously unknown ascorbic acid derivative (2) along with 48 known compounds including three ascorbic acid derivatives (3-5), three diarylheptanoids (6-8), three juglone derivates (9-11), six racemic α-tetralones (12a/b-17a/b), four anthraquinones (18-21), eight flavonoids (22-29), nine oligomeric proanthocyanidins (30-38), one phenolic aldehyde (39), one aromatic ketone (40), one pyrrole alkaloid (41), one steroid (42), six terpenes (43-48) and two fatty acids (49-50) were isolated from the leaves of Juglans regia. Their chemical structures were elucidated on basis of 1D and 2D NMR techniques, HRESIMS, polarimetry and CD spectroscopy as well as chiral HPLC and literature data. Furthermore, the chemotaxonomic significance is discussed.