Smenoqualone a novel sesquiterpenoid from the marine sponge Smenospongia sp.

Smenoqualone, a novel quinonic terpenoid with a rearranged drimane skeleton was isolated from a marine sponge Smenospongia sp. The stereostructure was determined by detailed analyses of ¹H and ¹³C NMR spectra, ¹H-¹H COSY, ¹H-¹³C correlations via HMQC, HMBC and NOE difference NMR experiments.     

海绵Rhaphisia pallida的化学成分研究(I)──两种结构罕见的十元杂环化合物的结构测定

从海绵RhaphisiaPallida中分离到2个白色晶体,经综合运用波谱方法测定出它们的结构,是2个十分罕见的具有二酰亚胺基和脲基的十元杂环新化合物.     

DITERPENOIDS FROM RABDOSIA SCULPONEATA

Five ent-6,7-seco-karuene diterpenoids-enmein,epinodosin,sculponeatin A,C,D,were isolated from thedried leaves of Rabdosia sculponeata One of the compounds,named sculponeatin D,was previously unreported.Itsstructre was elucidated by the spectral data including 2D COSY,~1H-~(13)C correlation,2D NOESY spectroscopy.     

A new C27-steroidal glycoside from Ophiopogon japonicus

A new C27-steroidal glycoside with three known compounds were isolated from the tuber of Ophiopogonjaponicus （Thunb.） Ker-Gawl. Based on the spectral analysis, including HRMS, 1H NMR, 13C NMR, DEPT, 1H-1H COSY, HMQC and HMBC, their chemical structures were determined as pennogenin-3-O-α-L-rhamnopyranosyl-（1→ 2）-β-D-xylopyranosyl-（1→ 4）-13-D-gluco- pyranoside （1）, pennogenin-3-O-α-L-rhamnopyranosyl-（1→ 2）-β-D-glucopyranoside （2）, ophiopojaponin C （3） and ophiopogonin D （4）. 2007 Jian Zhong Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.     

Sono-chemical Synthesis and Mechanism of Dibenz[a,c]anthracene

Planar polycyclic aromatic hydrocarbons have important applications in optoelectronics,environmental chemistry and cancer researches.An improved sono-chemical synthetic procedure of dibenz[a,c]anthrace...     

INVESTIGATION OF CHEMICAL CONSTITUENT FROM CELASTRUS ANGULATUS

Three new β-dihydroagarofuran sesquiterpene polyol esters,one alkaloid andtwo non-alkaloids,were isolated from the MeOH extract of seed oil of Celastrus angulatus.Their structures were elucidated on the basis of UV,IR,mass,NOE difference,~1H-NMR,~(13)C-NMR and ~1H-~(13)C long-range correlation spectroscopy.     

南蛇藤昆虫拒食成分的研究(I)

南蛇藤昆虫拒食成分的研究（Ｉ）王明安,陈馥衡（北京农业大学应用化学系,北京,１０００９４）关键词南蛇藤,倍半萜,结构分析南蛇藤（Ｃｅｌａｓｔｒｕｓｏｒｂｉｃｕｌａｔｕｓ）是我国传统的低毒杀虫植物,其主要化学成分为倍半萜［１］．Ｓｍｉｔｈ等［２,３］对...     

酞侧基聚芳醚酮的核磁共振研究(Ⅰ)──链结构及NMR谱的归属

用1D NMR方法研究酞侧基聚芳醚酮(PEK-C)链结构,用二维同核化学位移相关与二维异核化学位移相关实验方法对1D NMR谱峰进行归属,探讨了二维异核远程相关实验在缩聚高分子研究中的应用,为PEK-C修饰机理以及共混相容机理的研究提供重要信息。溶液NMR谱图数据表明,PEK-C具有较规整的链结构。     

南蛇藤昆虫拒食倍半萜成分的研究(Ⅱ)

南蛇藤昆虫拒食倍半萜成分的研究（Ⅱ）王明安,陈馥衡（北京农业大学应用化学系,北京,１０００９４）关键词南蛇藤,倍半萜,结构分析卫矛科植物含多种类型β－二氢沉香呋喃倍半萜多醇酯衍生物和生物碱［１］,有些化合物显示了良好的昆虫拒食和抗肿瘤活性［２～４］．...     

NEW STEROIDAL CONSTITUENTS FROM AMALOCALYX YUNNANESIS----Ⅰ.

Two C_(21)-steroids,named amalogenin A amd amaloside A were isola-ted from the rhizome of Amalocalyx yunnanesis.Their structures were estab-lished by analysis on the spectra of NMR including ~1H-~1H cosy,~(13)C-~1H COSYand confirmed by X-ray diffraction.     

The complete assignment of the h and C nmr spectra of the alkali metal salts of salinomycin and narasin

The preparation of the alkali metal salts of salinomycin and narasin, apart from lithium narasin, is described. The complete assignment of their ¹H spectra based on two dimensional COSY and NOESY spectra is reported. These asignments are then used in two dimensional ¹³C/¹H correlations via direct and long range couplings to assign the ¹³C spectra. Assignments in the ¹³C spectrum of sodium salinomycin differ in important details from those in a previous report.     

H, C NMR spectral and single crystal structural studies of toxaphene congeners. Quantum chemical calculations for preferred conformers of 2,5-endo,6-exo,8,9,9,10,10-octachloro-2-bornene and their DFT/GIAO C chemical shifts

The ¹H and ¹³C NMR chemical shifts for six toxaphene congeners: 2-exo,3-endo,6-exo,8,9,10-hexachloro- (1), 2-exo,3-endo,5-exo,9,9,10,10-heptachloro- (2), 2-exo,3-endo,6-exo,8,9,10,10-heptachloro- (3), 2-exo,3-endo,5-exo,6-endo,8,9,10-heptachloro- (4), 2-exo,3-endo,5-exo,6-endo,8,9,9,10-octachlorobornane (5) and 2,5-endo,6-exo,8,9,9,10,10-octachloro-2-bornene (6) are reported. Their chemical shift assignments have been obtained by means of Pulsed Field Gradient (PFG) Double Quantum Filtered (DQF) ¹H,¹H correlation spectroscopy (COSY), PFG ¹H,¹³C Heteronuclear Multiple Quantum Coherence (HMQC) and PFG ¹H,¹³C Heteronuclear Multiple Bond Correlation (HMBC) experiments. A single crystal X-ray structural analysis was made for compounds 1, 3, 4 and 6. The prevalences of two octachlorobornene rotamers (6a,6b) were elucidated by ab initio MO method and single point DFT/GIAO calculations for ¹³C chemical shifts. Theoretical calculations proved that the single crystal structure of 6 corresponds its most stable conformer in solution.     

An investigation of solute-liquid crystal interaction in hydrogen bonded complexes of palmitic acid and p-octyloxybenzoic acid

The orientational order of a liquid crystalline phase which has a specific solute-liquid crystal interaction was investigated using nuclear magnetic resonance. Three isotopically substituted species of palmitic acid (palmitic acid-d₃₁, 1-¹³C-2.2-H₂-palmitic acid-d₂₉ and 2,2,3,3-H₄-palmitic acid-d₂₇) were dissolved in the liquid crystal p-octyloxybenzoic acid (p-OOBA) and the proton, deuteron and carbon 13 NMR spectra recorded as a function of temperature. ¹H-¹³H dipolar couplings were observed using a spin echo pulse sequence which removes heteronuclear dipolar couplings to the chain deuterons. In the case of the carbon 13 labelled compound, ¹H-¹³C dipolar couplings could be observed by applying an additional refocusing pulse to the ¹³C spins. The dipolar and quadrupolar couplings were used to calculate the complete orientational order matrix of the alpha methylene segment of palmitic acid in p-OOBA. The liquid crystal was shown to largely determine the orientational order of the head group and this was attributed to intermolecular hydrogen bonding. The dipolar and quadrupolar couplings for the rest of the chain were interpreted in terms of a mean field equilibrium statistical model, based on the Samulski Inertial Frame Model. Hydrogen bonding was shown to be of greater importance in the orientational ordering of the solutes in the liquid crystal than are electrostatic interactions in the ordering of the amphiphile in the potassium palmitate/water system.     

STUDIES ON THE CHEMICAL CONSTITUTIONS OF SONCHUS ARVENSIS L

Sonchus arvensis L. is one of perennial herbaceous plants of the composite family. It is abundant in China. It has the efficacy of for the treatment of fever, carbuncles and inflammation. Thirty-four compounds have been isolated and reported from the plant. In this paper, from the extraction of petroleum ether of sonchus arvensis L.,three chemical substances were isolated. By means of chemical and spectroscopic (IR, ¹H-NMR, ¹³C-NMR, ¹H-¹H COSY, MS) analysis, they were identified as n-hexacosanol (Ⅰ), α-amyrin (Ⅱ) and santoman (Ⅲ). Among them Ⅱ and Ⅲ are the first time isolated from this genus.     

NMR spectra of salicylohydroxamic acid in DMSO-d6 solution: a DFT study

The ¹H, ¹³C and ¹H, ¹³C COSY NMR spectra of salicylohydroxamic acid (sha) were measured in DMSO-d₆ solution. The B3LYP GIAO method with the 6-311++G(d,p) basis set was chosen to reproduce the experimental spectra. All possible zusammen and entgegen conformers of monomeric sha were computed. After geometry optimisation (B3LYP/6-311++G(d,p)) only nine independent models of the molecule were shown to be stable. Additionally, the NMR chemical shifts of the Onsager model of the most stable monomer were calculated. The computed chemical shifts for the labile protons for all aforementioned geometries meaningfully underestimated experimental results suggesting the existence of the H-bonded structure of sha in DMSO solution. The most probable two dimeric structures along with two solvent-bounded aggregates were subsequently calculated at the same level of theory. The best agreement was obtained for sha H-bonded with two DMSO molecules (confirmed by the absence of concentration effect). The relative error not exceeding 10 and 4% for chemical shifts in ¹H and ¹³C NMR spectra of sha–(DMSO)₂, respectively, showed that the applied method with the B3LYP/6-311++G(d,p) basis set was efficient to predict the NMR shifts of a compound with strong H-bonds. Thus, this allows to assign properly NMR resonances to specific structure formed in DMSO solution.     

Structure Determination and Detailed of 1H and 13C NMR Spectra Assignments of Villosumcoronarine-a New Diterpene from Hedychium Villosum Wall (Zingiberaceae)

Villosumcoronarin, a new diterpene isolated from the dried leaves of Hedychium villosum Wall (Zingiberaceae), yellow crystal (Et₂O), m.pl08.4-108.8℃, has the molecular formula C₂₀H₂₈O₂ derived from ESIMS (m/z 301, positive and m/z 299, negative), EIMS (m/z 300) and ¹³CNMR (DEPT 90 and DEPT135) spectral data., whose structure was elucidated as labda-8 (17), ll, 13-triene-15-oic-16-lactone (Figure 1) by the NMR spectral studies. The detailed NMR resonance assignments of these compound were achieved by using the 2D-NMR,¹H-¹H COSY, HMQC, HMBC and NOESY tests and comparing the spectroscopic data with yunnancoronarin B^[1,2] (figure 2).     

式根岛海绵宏基因组文库的抗菌吲哚三聚体

构建了式根岛海绵的宏基因组文库,对其进行双层琼脂抗菌活性功能筛选,得到1株抗菌活性克隆pDC111. 以抗菌活性为指导,对pDC111的化学成分进行分析和分离,得到化合物1,并通过1D NMR（¹H NMR和 ¹³C NMR）及2D NMR（¹H-¹H COSY,HMQC和HMBC）结合HR-TOFMS数据,确定其结构为吲哚三聚体. 抗菌活性实验结果表明,化合物1在10 μg/paper（id=6 mm）时,对蜡状芽孢杆菌的抑菌圈达到12 mm. 本文利用功能宏基因组方法,从蕴藏大量不可培养微生物的海绵中寻找到活性物,并具有通过分子生物学技术获得其功能基因的潜能.     

新的醚链双生物碱尖叶唐松草阿原碱的结构测定

从尖叶唐松草〔Thalictrumacutifolium(Hand.Mazz.)Boivin〕根分离得到一种新生物碱(尖叶唐松草阿原碱).通过IR,MS,¹HNMR,¹³CNMR,2DNMR(包括¹H-¹HCOSY,¹³C-¹HCOSY,NOESY和HMBC)测定了其化学结构,发现由阿朴菲和原小蘖碱通过醚链连接.对多种肿瘤细胞的生长有抑制作用,并有凋亡现象出现,而且对正常细胞的毒性较小     

Rearrangement of cyclooctyne to 1,2-cyclooctadiene within the coordination sphere of CpMn(CO)2

The synthesis of isomeric complexes of CpMn(CO)₂(C₈H₁₂) is reported. Reaction of CpMn(CO)₂THF with cyclooctyne yields cyclooctyne complex 1 which has been characterized by ¹H and ¹³C NMR and infrared spectroscopy. The alkyne carbons exhibit an unusual upfield shift upon coordination. The alkyne moiety in this complex is prone to rearrangement to allene complex 2 which has been characterized by ¹H and ¹³C NMR and IR spectroscopy. Assignment of each resonance was achieved through 2D COSY NMR experiments. The isomerization of 1 to 2 is accelerated by passing 1 down a silica gel chromatography column. The presumed strain relief upon complexation of the strained alkyne to the metal center is not sufficient to prevent isomerization from occurring.     

The structure and conformation of a mesogenic compound between almost zero and almost complete orientational order

The conformational distributions in molecules that form liquid crystalline phases are predicted to depend strongly on orientational order. Results are presented here to test this hypothesis. The mesogen 4-hexyloxy-4'-cyanobiphenyl (6OCB) has been studied by NMR spectroscopy in the isotropic phase and in the nematic phase. In the isotropic phase the field-induced orientational ordering produces small dipolar couplings between ¹³C and ¹H nuclei, which were determined from the ¹³C spectra. Couplings between ¹H nuclei were also obtained using 2D selective refocusing experiments. In the nematic phase, both ¹H-¹H dipolar couplings and quadrupolar splittings for deuterium nuclei were measured for partially-deuterated samples. Both proton and deuterium spectra were also obtained for 6OCB in an equimolar mixture with 4-(ethoxybenzylidene)-4'-butylaniline (EBBA). This mixture exhibits SmA and SmB phases. The data obtained from these experiments has been analysed to yield the probability distribution of the conformations in this molecule generated by rotations about bonds. It is found that there is a substantial influence of the orientational order of the molecules on these distributions.