太空育种射干的X射线荧光及X射线衍射分析和表征

联用X射线荧光光谱(XRF)和粉末X射线衍射(PXRD)方法,对我国独创的第4代太空诱变育种射干中多种元素种类和含量及晶态物质进行了研究。结果表明:太空组射干K元素含量比地面组、对照品分别提高了1.03和0.31倍,Mg元素分别提高了1.44和0.06倍,Ca,Mn和Fe元素含量比地面组分别提高了0.95,0.30和0.29倍,Al元素比地面组、对照组分别降低了38.5%和85.5%,并在射干中鉴别出一水草酸钙(CaC2O4.H2O)晶体,晶体含量是地面组<太空组<对照品。从而可得出结论:太空射干中人体必需的矿质元素比地面组都更接近或优于对照品。文章研究结果和方法对筛选品质优良的太空药材籽种和推广种植太空药材以及建立中药材质量评价标准,有积极的作用和重要意义。     

中国对虾PENAEUS CHINENSIS (O'SBECK)肌肉系统的研究 亚.眼柄及附肢肌肉的解剖3}

本文描述中国对虾附肢肌肉(第一步足、第五步足、第三游泳足)解剖学结构，所得结果与白对虾Penaeus setiferu:作比较，其不同之处列于表1.     

A New Taxoid from Leaves and Branches of Taxus chinensis

A new taxoid, 2-deacetyl-2α, 14β-dihydroxybaccatin Ⅳ (1), was isolated from the leaves and branches of Taxus chinensis together with the known compound baccatin Ⅳ (2). The structure of the new compound was elucidated by spectroscopic techniques. The detailed ^13C NMR assignments of baccatin Ⅳ are reported for the first time.     

Diastereoisomeric saponins from the rhizomes of Tupistra chinensis

A pair of diastereoisomeric furostanol saponins was obtained from the n-butanol fraction of methanol extract from Tupistra chinensis rhizomes,a folk medicine of Shennongjia Forest District of Hubei Province.Their structures were determined,on the basis of chemical and spectroscopic evidences.     

Enantioselective synthesis of heliannuol E; structural consideration of natural molecule

Heliannuol E 1, isolated from Helianthus annuus L. cv. SH-222, was successfully synthesized in both optically active forms, by novel ring-expansion reaction of the corresponding spirodienone derivatives 8 and 17, which were produced from 7 and 16 under anodic oxidation conditions. The absolute structure of the natural product was determined to have R-configuration at the benzylic position.     

石香薷中两个新黄酮甙的研究

石香薷中两个新黄酮甙的研究郑尚珍，孙丽萍，沈序维王毅（西北师范大学化学系，兰州，７３００７０）（中国科学院兰州化学物理研究所）关键词石香薷，唇形科，黄酮甙唇形科植物石香薷（ＭＯｓｌａｃｈｉｎｅｎｓｉｓＭａｘｉｍ）作为中药，用来治疗暑湿感冒、头痛、腹痛...     

Simultaneous determination of 12 active components in the roots of Pulsatilla chinensis using tissue‐smashing extraction with liquid chromatography and mass spectrometry

Ultra high performance liquid chromatography coupled with mass spectrometry and combining a tissue‐smashing extraction technique was developed for the simultaneous quantitative analysis of 12 compounds in the roots of Pulsatilla chinensis . Among them, compound 6 was characterized and accurately quantified in this herb for the first time. The parameters of extraction condition were simultaneously optimized with a Box–Behnken design and Derringer's function. The optimized conditions were as follows: sample quantity of 0.5 g, ethanol concentration of 70%, and extraction time of 200 s. Multiple‐reaction monitoring scanning was employed for the quantification between positive and negative mode in a single run of 6 min. Full validation of the method was carried out, and the results indicated that the method was rapid, specific, and reliable. The developed method was successfully applied to quantify the 12 compounds in 33 batches of P. chinensis from different provinces. Moreover, the principal component analysis was performed to compare the P. chinensis collected from different provinces of China based on quantitative data and the results indicated that the content of compounds could be used to differentiate the origins of P. chinensis . These results demonstrated that this method is feasible and reliable for the quality control of P. chinensis .     

A New Triterpenoid Oligoglycoside Escin IVe from the Seeds ofAesculus Chinensis

Inthecourseofourstudiesonnewbiologicallyactivesaponinsofnaturalmedicines,wehaveisolatedescinsla.fo.IVa.IVb,IVc,andIVdtyolnseedsof.4e'v"11/llSchinensisBee.(Hippocastanaceae),andsinglecrystalX-raydiffractionanalysiswasundertakenonescinla'.whichconfirmstheabsoluteconfigurationandsugarsequence.ThepresentpaperdescribesthestructuredeterminationofanewtriterpenoidsaponinnamedescinIVefromthesameplant.EscinIVe,whitepowder.Positive-modeTOF-MScm/zI111[M Na] ,coupledwitllNMRdata.correspondstoane…     

Furofuran Lignans from Cuscuta chinensis

Three furofuran lignans named neocuscutasides A, B and C were obtained from the ethanolic extract of the dried seeds of Cuscuta chinensis and their structures were characterized by chemical and spectroscopic methods.     

An Algorithm for l∞ Regression with Quadratic Complexity

Using a few very basic observations, we proposed recently a direct and finite algorithm for the computation of the l regression line on a discrete set under the assumption that In this paper, we extend the algorithm to the case with at least one, possibly multiple y-values for each distinct x_i. Our algorithm finds all the regression lines in O(n ²) operations in the worst-case scenario and improves the existing best-known computational complexity result for this problem. Numerical results on random problems are included.