Lycobelines A-C, Novel C16N2-type Lycopodium alkaloids from Huperzia goebelii

Novel C₁₆N₂-type Lycopodium alkaloids consisting of a decahydroquinoline with an aminohexyl side chain, lycobelines A-C (1-3), were isolated from the club moss of Huperzia goebelii, and their structures and relative stereochemistry were elucidated on the basis of spectroscopic data and chemical correlations.     

Hupermine A,a novel C16N2-type Lycopodium alkaloid from Huperzia phlegmaria

A novel C₁₆N₂-type Lycopodium alkaloid consisting of a quinolizidine with a 6-dimethylaminohexyl side chain, hupermine A (1), was isolated from the club moss of Huperzia phlegmaria, and the structure and relative stereochemistry were elucidated on the basis of spectroscopic data.     

Senepodines B-E, new C22N2 alkaloids from Lycopodium chinense

Four new C₂₂N₂Lycopodium alkaloids, senepodines B-E (2-5), consisting of an octahydroquinoline ring and a quinolizidine ring have been isolated together with senepodine A (1) from the club moss Lycopodium chinense. The relative and absolute stereochemistry of 2-5 were determined by combination of NOESY correlations and chemical transformation, while the absolute configuration of 1 was assigned by exciton chirality method.     

Feroniellins A-C, novel cytotoxic furanocoumarins with highly oxygenated C10 moieties from Feroniella lucida

Three new furanocoumarins, named feroniellins A (1), B (2), and C (3), were isolated from the roots of Feroniella lucida. Compounds 1-3 are novel structures having an oxolane, oxane, and oxepane moiety. Their overall structures and configurations were determined by spectral and chemical methods. The cytotoxicities of 1-3 were evaluated against human KB and HeLa carcinoma cells.     

The pure rotational Raman spectra of cyanogen, C2N2 and C2N2

The pure rotational Raman spectra of C₂¹⁴N₂ and C₂¹⁵N₂ have been recorded photographically using a 3-metre spectrograph with a reciprocal linear dispersion of 1.4 cm⁻¹ mm⁻¹ at 488.0 nm and analysed to give the rotational and centrifugal distortion constants for both species. Corrections were applied to compensate for the effect of molecules in excited vibrational states on the pure rotational spectra. Comparisons are made with previous infrared vibration—rotational studies on these species and with previous Raman studies on C₂¹⁴N₂. The following bond lengths were calculated: r₀(C---N) = 116 ± 1 pm; r₀(C---C) = 138 ± 2 pm.     

Zn(C3H3N2)2: a novel diamagnetic insulator

We have prepared polycrystalline samples of Zn(C₃H₃N₂)₂ by a liquid-mix technique. Characterization of the obtained samples has been performed with the aid of elemental, thermogravimetric, infrared spectra and X-ray powder diffraction analysis. We have measured electric permittivity (ε′, ε″), ac-conductivity (σ_ac), magnetic susceptibility (χ) and specific heat (C_p). The obtained data indicate that this material is a new diamagnetic insulator. A maximum around is found in C_pT⁻³, and it is suggested that in addition to the Debye lattice contribution, there exists a low-frequency mode assigned as an Einstein mode contribution to the total specific heat. As a main result of the study, we found ε′ to be constant in a wide temperature range and to have a small value of 2.3 at room temperature. This feature in combination with other properties like crystallization, good thermal stability (up to 400°C), weak moisture sensitivity and simple synthesis makes Zn(C₃H₃N₂)₂ to be a promising candidate for good insulating material in various applications.     

Lycopladines F and G, new C16N2-type alkaloids with an additional C4N unit from Lycopodium complanatum

Two new Lycopodium alkaloids, lycopladines F (1) and G (2), have been isolated from the club moss Lycopodium complanatum, and the structures and relative stereochemistries of 1 and 2 were elucidated on the basis of spectroscopic data. Lycopladine F (1) is a rare C₁₆N₂-type Lycopodium alkaloid possessing an amino acid residue (C₄N).     

Malonganenones A-C, novel tetraprenylated alkaloids from the Mozambique gorgonian Leptogorgia gilchristi

Three novel tetraprenylated alkaloids, malonganenones A-C (1-3), were isolated from the gorgonian Leptogorgia gilchristi collected near Ponto Malongane, Mozambique. Compound 1 is the first 3,7-disubstituted hypoxanthine to be discovered from a marine source, while 2 and 3 represent the first formamides to be isolated from gorgonians. The unexpected facile exchange of the formamide proton of 2 with a deuteron originating from the NMR solvent used for spectroscopic analysis hampered initial attempts at the structural elucidation of this compound. The anti-oesophageal cancer activities of 1-3 are compared with that of rietone (4), a related triprenylated compound previously isolated from a South African soft coral.     

Lannotinidines A-G, new alkaloids from two species of Lycopodium

Seven new Lycopodium alkaloids, lannotinidines A-G (1-7), have been isolated from the club moss Lycopodium annotinum and L. annotinum var. acrifolium. Stereochemistry of 1-7 was elucidated by combination of NOESY correlations and chemical transformation. Lannotinidines B-E (2-5) elevated NGF mRNA expression.     

Lyconadins C and F, new Lycopodium alkaloids from Lycopodium complanatum

New Lycopodium alkaloids, lyconadins C (1) and F (2), were isolated from the club moss Lycopodium complanatum. Lyconadin C (1) is a new C₁₆N₂-type Lycopodium alkaloid possessing unique fused-tetracyclic ring system consisting of a cycloheptene ring fused to a decahydroquinoline and pyridone rings. Lyconadin F (2) possesses a primary amide moiety in its molecular, which is the first example of Lycopodium alkaloids. Biogenetically, lyconadins C (1) and F (2) might be related to lyconadins A (4) and B (5). The structures and relative stereochemistry of 1 and 2 were elucidated on the basis of spectroscopic data. The absolute stereochemistry of 2 was elucidated by chemical correlations with lyconadin B (5) through hemiaminal form of lyconadin F (3).     

Synthesis, structure and optical properties of new organic-inorganic haloplumbates complexes (C5H10N3)PbX4 (X=Br, Cl), (C2H2N4)PbBr3

Layered organic-inorganic composite materials (C₅H₁₀N₃)PbX₄ (X=Br 1, Cl 2) containing histaminium dications were grown via a solution-cooling process, and their structure and optical properties were determined. The organic ligand-histaminium introduced into the corner-sharing octahedra of the ‘PbX₄-layer’ contains both primary ammonium and imidazolium different from the traditionally primary amine found in this system. As comparison, another analogous amine of 3-amino-1,2,4-triazol was used as ligand to coordinate with PbBr₂ in acid solution. A novel complex (C₂H₂N₄)PbBr₃ (3) was obtained with zigzag PbBr₂ chains different from the PbX₄ layer in compound as 1 and 2. The hybrid (C₅H₁₀N₃)PbX₄ show exciton absorption at 339 nm for X=Cl and 419 nm for X=Br with the corresponding emission at 360 and 436 nm, respectively. The different PbBr₂ chain structure of compound 3 does not show photoluminescence.     

Ten new fawcettimine-related alkaloids from three species of Lycopodium

Ten new fawcettimine-related alkaloids, i.e., lycopoclavamines, lycoposquarrosamine-A, and other hydroxylated fawcettimine derivatives, were isolated from three species of Lycopodium (Lycopodium clavatum, Lycopodium serratum, and Lycopodium squarrosum). The structures of the new alkaloids were elucidated by spectroscopic methods and chemical correlation.     

Antimicrobial indole alkaloids with adductive C9 aromatic unit from Gelsemium elegans

Gelselegandines A-C (1–3), three unprecedented gelsedines incorporating additional C₉ aromatic unit as side chain, were isolated from Gelsemium elegans. Their structures were elucidated by means of spectroscopic techniques and electronic circular dichroism (ECD) calculation. Additionally, gelselegandines A–C showed moderate antimicrobial activities against four bacterial strains and two fungi.     

Theoretical study of C24N4 molecule

Both ab initio 6-31G, 3-21G and STO-3G basis sets and semiempirical PM3 and AM1 molecular orbital calculations are carried out on the C₂₄N₄ molecule of the T_d symmetry group. Results on the fully optimized structure which constrained T_d symmetry, molecular orbitals and vibrational frequency were obtained by both ab initio and semiempirical methods. The binding energy and various thermodynamic properties were also calculated via the PM3 and AM1 semiempirical methods. All the evidence of this work proves that the C₂₄N₄ molecule is stable and that its four six-membered rings with a remarkable delocalized C…C bond are similar to the related rings in the C₆₀ buckminsterfullerene structure.     

Lycogladines A-H,fawcettimine-type Lycopodium alkaloids from Lycopodium complanatum var. glaucum Ching

Five new fawcettimine-type alkaloids (1–5) and three new natural products (6–8), along with four known analogues, fawcettimine (9), fewcettidine (10), lycopoclavamine B (11), and lycopladine B (12), were isolated from the whole plant of Lycopodium complanatum var. glaucum Ching. The structures of lycogladines A-H (1–8) were determined based on HRESIMS, 1D and 2D NMR spectroscopic analysis, as well as single-crystal X-ray diffraction. Compound 1 possesses a new ring system that is formed through the linkage of C-13-OC-2, which is rarely present in Lycopodium alkaloids (LAs). Compounds 1–8 were tested for their β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) and acetylcholinesterase (AChE) inhibitory activities.     

Three new Lycopodium alkaloids from Huperzia carinata and Huperzia squarrosa

Eleven Lycopodium alkaloids with lycodine-type, lycopodine-type, and fawcettimine-related skeletons were isolated from the whole plants of Huperzia carinata (Desv. Ex. Poir.) Trevis and Huperzia squarrosa (G. Forst) Trevis (Huperziaceae). Among them, 8,15-dihydrohuperzine A (2), lycocarinatine A (3), and lycoposerramine U N-oxide (11) are new compounds. The structures of these new alkaloids were elucidated on the basis of 2D NMR correlations. Some of these isolated alkaloids were assayed for acetylcholinesterase (AChE) inhibitory activity.     

New phlegmarane-type, cernuane-type, and quinolizidine alkaloids from two species of Lycopodium

Two new phlegmarane-type alkaloids, cermizines A (1) and B (2), three new quinolizidine alkaloids, cermizine C (3) and senepodines G (4) and H (5), and a new C₁₆N₂ type alkaloid consisting of a quinolizidine and a piperidine ring, cermizine D (6), as well as two new cernuane-type alkaloids, cernuine N-oxide (7) and lycocernuine N-oxide (8), have been isolated together with cernuine (9) and lycocernuine (10) from the club moss Lycopodium cernuum and L. chinense. The relative stereochemistry of 1-4 and 6, and the absolute stereochemistry of 5, 7, and 8 were elucidated by combination of NOESY correlations, modified Mosher's method, chemical transformations, and computational methods. Cermizine D (6) might be a biosynthetic intermediate of cernuane-type alkaloids such as 7-10.     

Co/C3N4 NTs复合纳米材料的制备及光催化性能

采用化学还原法将非贵金属钴纳米颗粒沉积到氮化碳纳米管（C₃N₄ NTs）内外管壁,制备了Co/C₃N₄ NTs复合光催化剂。使用多种分析表征手段对Co/C₃N₄ NTs的形貌和结构进行分析,并比较Co负载量对复合材料可见光光催化产氢性能的影响。结果表明,该金属-半导体异质结可有效增强光生电子-空穴的分离速率。经可见光照射2 h后,当Co负载量为质量分数5%时具有最佳产氢量,且产氢速率为纯C₃N₄ NTs的1.7倍。     

Sauroine—a novel Lycopodium alkaloid from Huperzia saururus

A novel Lycopodium alkaloid, sauroine (7,8-dihydroxylycopodine, 1) was isolated from the aerial parts of the medicinal species Huperzia saururus. The structure and relative stereochemistry of 1 were elucidated on the basis of its spectral data.