Structure of a dimer of ageratochromene

A solid obtained in the dimerisation of ageratochromene (6,7-dimethoxy-2,2-dimethyl-1-benzopyran)(II) in the presence of acid has been shown to be 5,6,6a,6b,7,12b-hexahydro-1,2,10,11-tetramethoxy-5,5,7,7-tetramethylcyclopenta[1,2-c;5,4,3-de]bis[1]benzopyran (IV) by a study of its n.m.r. and mass spectra.

Organometallic chemistry of diphosphazanes. Part 26. Ruthenium hydride complexes of chiral and achiral diphosphazane ligands and asymmetric transfer hydrogenation reactions

The half-sandwhich ruthenium chloro complexes bearing chelated diphosphazane ligands, [(eta(5)-Cp)RuCl{kappa(2)-P,P-(RO)(2)PN(Me)P(OR)(2)}] [R = C6H3Me2-2,6] (1) and [(eta(5)-Cp*)RuCl{kappa(2)-P, P-X2PN(R)PYY'}] [R = Me, X = Y = Y' = OC6H5 (2); R = CHMe2, X-2 = C20H12O2, Y = Y' = OC6H5 (3) or OC6H4'Bu-4 (4)] have been prepared by the reaction of CpRu(PPh3)(2)Cl with (RO)(2)PN(Me)P(OR)(2) [R = C6H3Me2-2,6 (L-1)] or by the reaction of [Cp*RuCl2](n) with X2PN(R)PYY' in the presence of zinc dust. Among the four diastereomers (two enantiomeric pairs) possible for the "chiral at metal" complexes 3 and 4, only two diastereomers (one enantiomeric pair) are formed in these reactions. The complexes 1, 2, 4 and [(eta(5)-Cp)RuCl {kappa(2)-P,P-Ph2PN((S)-*CHMePh)PPhY)] [Y = Ph (5) or N2C3HMe2-3,5 (SCSPRRu)-(6)] react with NaOMe to give the corresponding hydride complexes [(eta(5) -Cp)RuH {kappa(2)-P,P-(RO)(2)PN(Me)P(OR)(2)}] (7), [(eta(5)-Cp*)RuH {kappa(2)-P,P'-X2PN(R)PY2)] [R = Me, X = Y = OC6H5 (8); R = CHMe2, X-2 = C20H12O2, Y = OC6H4'Bu-4 (9)] and [(eta(5) -Cp)RuH(kappa(2)-P, P-Ph2PN((S)-*CHMePh)PPhY)][Y =Ph (10) or N2C3HMe2-3,5 (SCSPRRu)(11a) and (SCSPSRu)-(11b)]. Only one enantiomeric pair of the hydride 9 is obtained from the chloro precursor 4 that bears sterically bulky substituents at the phosphorus centers. On the other hand, the optically pure trichiral complex 6 that bears sterically less bulky substituents at the phosphorus gives a mixture of two diastereomers (11a and 11b). Protonation of complex 7 using different acids (HX) gives a mixture of [(eta(5)- Cp)Ru(eta(2)-H-2){kappa(2)-P, P-(RO)(2)PN(Me)P(OR)(2))]X (12a) and [(eta(5)-Cp)Ru(H)(2){kappa(2)-P, P-(RO)(2)PN(Me)P(OR)(2)}]X (12b) of which 12a is the major product independent of the acid used; the dihydrogen nature of 12a is established by T, measurements and also by synthesizing the deuteride analogue 7-D followed by protonation to obtain the D-H isotopomer. Preliminary investigations on asymmetric transfer hydrogenation of 2-acetonaphthone in the presence of a series of chiral diphosphazane ligands show that diphosphazanes in which the phosphorus centers are strong pi-acceptor in character and bear sterically bulky substituents impart moderate levels of enantioselectivity. Attempts to identify the hydride intermediate involved in the asymmetric transfer hydrogenation by a model reaction suggests that a complex of the type, [Ru(H)(Cl){kappa(2)-P,P-X2PN(R)PY2)(solvent)(2)] could be the active species in this transformation. (c) 2007 Elsevier B.V. All rights reserved.

THE RESPONSES OF Microcystis TO SEDIMENT ENVIRONMENTS AND THE ASSESSMENT FOR ITS OVERWINTERING - A SIMULATION STUDY IN A NOVEL DEVICE

A novel multi-cell device made of organic glass was designed to study morphological and physiological characteristics of Microcystis population trapped in simulated sediment conditions. Changes of colonial morphology and antioxidant activities of the population were observed and measured over the range of 31-day incubation. During the incubation, the antioxidant enzyme activities fluctuated significantly in sediment environments. The activities of catalase (CAT), glutathione peroxidase (GPx) and malondialdehyde (NIDA) reached the highest on the 11(th) day, 6(th) day and 6(th) day. respectively, and then dropped down remarkably in the following days. The ratios of Fv/Fm and the maximal electron transfer rate (ETRm) declined during the initial days (1 similar to 11(th) day), but rebounded on the 16(th) day, which were consistent with the variations of total protein. In the end of incubation. gas vacuoles were hard]), observed and the gelatinous sheath was partly disappeared in the population of Microcystis. Nevertheless, the remaining populations. upon transferred to culture medium, were able to grow though experiencing a longer lag phase of nine days. The results indicated that the sediment environments were able to cause negative effects on M. aeruginosa cells. The cells, however, responded to against the possible damage afterwards. It is thus proposed the acute responses in the population during the early stage of sedimentation could be of importance in aiding the long-term survivor of Microcystis and recruitment in lake sediments. The present study also demonstrated the utility of the device in simulating the sediment environments for further investigation.

ADSORBABILITY AND SEDIMENTATION EFFECT OF SUBMERGED MACROPHYTES ON SUSPENDED SOLIDS

To select better plant species for adsorption and deposition of suspended solids in water, effectively, eight species of submerged macrophytes, which are popular in the middle or downstream area of Yangtze River, were studied. The effects of their adsorbability and sedimentation on suspended solids were monitored in the microcosm systems with natural lake's sediment and water. Within one week's regular disturbance, according to their adsorbability of the macrophytes on suspended solids, the macrophytes were divided into two groups. Elodea nuttallii, Potamogeton crispus, Hydrilla verticillata, Myriophyllum spicatum, Potamogeton malaianus and Najas graminea were the macrophytes with stronger adsorbability. Vallisneria natans and Ceratoplyllum demersum were the macrophytes with weaker adsorbability. The average adsorbabilities of the two groups were 28.0 and 14.5 mg g(-1) FW-1, respectively. According to the sedimentation rate, the macrophytes were divided into three groups. P. crispus and H. verticillata were in the highest group. V.natans was in higher group. E nuttallii, M. spicatum, N. graminea, C demersum and P. malaianus were in the lowest group. The average sedimentation rates of the three groups were 3.42, 2.11 and 0.69 mg l(-1) d(-1). respectively. Therefore, P. crispus and H. verticillata were excellent species. C demersum was a poor species to improve transparency of water body.

丁香和升麻的化学成分研究

本论文由三部分共四章组成。第一部分介绍丁香化学成分的研究成果，第二部分为升麻的化学成分研究，第三部分综述了环菠萝蜜烷三萜结构和活性关系的研究现状。 第一部分包括第一和第二章。第一章介绍了丁香（Eugenia caryophyllataThunb.）花蕾的化学成分和结构鉴定。采用正、反相硅胶柱层析等各种分离方法，从其乙醇提取物的乙酸乙酯萃取物和正丁醇萃取物中共分离出34 个化合物，它们的结构类型分属黄酮、三萜、鞣质等。其中1 个为新的酚苷类化合物，其结构经波谱分析鉴定为2-O-(6'-O-没食子酰基)-b-D-葡萄糖基苯甲酸甲酯（24），另外还有12 个化合物为首次从该植物中分离得到。第二章介绍了丁香挥发油的气相色谱- 质谱联用（ GC-MS ）和正丁醇萃取物的高效液相色谱- 质谱联用（HPLC-MS/MS）分析，尝试简单快速地检测丁香挥发油及极性部分的主要化学成分的方法。 第二部分为第三章。本章介绍了传统中药升麻（Cimicifuga foetida L.）根部乙醇提取物化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化方法和MS、NMR 等波谱解析技术，共分离鉴定了20 个化合物，主要为环菠萝蜜烷三萜，其中5 个新三萜化合物分别鉴定为cimicidol-3-one（38）、3'-O-乙酰基升麻苷H-1（41）、2'-O-乙酰基升麻苷H-1（42）、(3b,12b,16b)-12-乙酰氧-16,23-环氧-9,19-环羊毛甾烷-22-烯-24-酮3-O-b-D-吡喃木糖苷（44）和升麻碱（54）。新化合物54 为结构新颖的环菠萝蜜烷三萜皂苷生物碱，这是首个发现的具有环菠萝蜜烷三萜骨架的生物碱，也是从升麻属植物中发现的第一个三萜生物碱，它的结构通过多种波谱解析，特别是2D-NMR 的充分应用，并结合化学降解和反应得到证实。此外，还介绍了分离得到的一种具有明显抑制破骨细胞活性的化合物(QS29)的体外活性研究。 第三部分即第四章，综述了升麻属植物中环菠萝蜜烷三萜与其生物活性的构效关系研究现状。 This dissertation consists of three parts. In the first and the second parts, thechemical constituents from the flower buds of Eugenia caryophyllata and therhizomes of Cimicifuga foetida were reported. The third part is a review on astructure-activity relationship of the cycloartane triterpenoid from Cimicifuga species. The first part is composed of two chapters. The chapter 1 is about the isolationand identification of the chemical constituents from the flower buds of E.caryophyllata. A new phenolic glucoside gallate, methyl 2-O-(6’-O-galloyl)-b-D-glucopyranosylbenzoate (24), together with thirty-three known compounds has beenisolated from the ethanol extract of the flower buds of E. caryophyllata throughrepeated column chromatography on normal and reversed phase silica gel. Thestructure of the new compound was elucidated on the basis of spectral and chemicalevidence. Those kno wn compounds were belonged to flavone, triterpenoid, tannin andsome simple compounds. Among them, 12 compounds were isolated from the titleplant for the first time. The second chapter describes the capillary GC-MS analysis ofthe volatile components and the HPLC-MS/MS analysis of the polar constituents fromthe flower buds of E. caryophyllata, in order to detect the main constituents in thecrude extract rapidly and precisely. The third chapter is about the chemical constituents of the rhizomes C. foetida, atraditional Chinese medicine which was used as anti-inflammatory, analgesic andantipyretic agents. Our investigation of the bioactivities constituents of the rhizomesof C. foetida led to the isolation of five new cycloartane triterpenoids, which werecharacterized as cimicidol-3-one (38), 3'-O-acetyl cimicifugoside H-1 (41),2'-O-acetyl cimicifugoside H-1 (42), (3b,12b,16b)-12-acetoxy-16,23-epoxy-9,19-cyclolanost-22-ene-24-one 3-O-b-D-xylopyranoside (44) and cimicifugadine (54),along with fifteen known compounds through repeated column chromatography onnormal and reversed phase silica gel. Among them, 54 is a novel cycloartanealkaloid and first discovered as a new type alkaoid from nature. The structures ofthese compounds were elucidated on the basis of spectral and chemical evidence, andcimicidol-3-one was confirmed by X-ray crystallography analysis. Moreover, onecompound exhibited strong anti-osteoporosis activity in vitro experiment. The fourth part is a review on a structure-activity relationship analysis of thecycloartane triterpenoid from Cimicifuga species.

A new potential radiosensitizer- multi-walled carbon nanotubes modified by ammonium persulfate

Here we prepare carbon nanotubes modified with ammonium persulfate, very short carbon nanotubes with 50-100 nanometer length was obtained, and the higher P potential of 52 mV was detected, these supporting the successful modification. HeLa cells were irradiated with P rays via adding or absent above functionalized carbon nanotubes (f- WCNTs) into cell culture medium with different concentration and radiation dosage. Confocal microscopy images and fluorescence-labeled DNA detection verified the successfully pure multi-walled carbon nanotubes (p-WCNTs) and f-WCNTs penetrated into cells. Compared with pure radiation, by MTT test, f-WCNTs induced cell death markedly with about 8.7 times higher than former one under little dose of radiation; meanwhile, no obvious toxicity was observed both in p-WCNTs and f-WCNTs without of radiation exposure. We hypothesized that large amount of hydroxyl and carbonyl organs on the surface of very short f-WCNTs changed into free radicals result from radiations led cell damage. These implied that f-WCNTs could be regarded as a new radiosensitizer.