短瓣花中的含氮化合物

从云南民间草药短瓣花（Brachystemma calycinum D.Don)根的乙醇提取物中首次分到6个化合物,包括5个含氮化合物及1个可能的人工产物。它们的结构经光谱及化学方法鉴定为短瓣花苷A（brachystemoside A,1),L- 焦谷氨酸甲酯（methyl L-pyroglutamate,2),腺嘌呤核苷（adenosine,3),2-吡咯甲酸（2－minaline,4),吡咯－2－羧酸－3'－糖酯（3'-furfuryl-pyrrole-2-carboxylate,5)及α－D－乙基葡萄糖苷（ethyl α－D－glucopyranoside,6)。其中化合物1为新化合物。     

短瓣金莲花中一个新的黄酮炭苷化合物

一个新的酰化黄酮炭苷化合物(1)和9个已知的黄酮炭苷从短瓣金莲花中分离得到,化合物1的结构通过HRMS、IR、1H、13C NMR、HMQC、HMBC等光谱学方法鉴定为7-甲氧基-2″-O-(2-甲基丁酰基)荭草苷.并以耳肿胀法评价所得黄酮化合物的抗炎活性.     

Cyclopeptidic Constituents from Arenaria oreophila J. D. Hooker （Caryophyllaceae）

To further investigate the cyclopeptldes of the Caryophyllaceae family, two new cyclopeptldes, named Arenarlphilin E （compound 1） and Arenariphilin F （compound 2）, were obtained from Arenaria oreophUe J. D. Hooker using some Isolation methods, e. g. normal and reverse silica gel. By detailed spectroscopic analysis, such as FAB^＋-MS, 1 D NMR, 2D NMR, the structures of Arenariphilin E （compound 1） and Arenariphilln F （compound 2） were determined as cyclo（lle^1-Gly-Val^1-Ala-Leu-lle^3-lle^2-Val^2-Pro） and cyclo（Pro^2-Pro^1-Gly^2-lle-Val-Leu-Gly^1-AiaThr- Gly^3）, respectively.     

鹰嘴豆蛋白降解产物的抗氧化作用

旨在分析鹰嘴豆分离蛋白(CPI)及其不同分子量短肽的抗氧化活性。用碱性蛋白酶(Alcalase)处理CPI,得到其降解产物,该降解产物经超滤离心,得到分子量分别为3 k D、3-5 k D、5-10 k D及10 k D的短肽。结果表明,与其它大分子肽段相比,3 k D的短肽具有较强的自由基清除活性;与谷胱甘肽(GSH)相比,CPI及其不同分子量短肽具有显著的金属离子螯合活性;CPI及其肽段具有一定的三价铁离子还原能力。上述结果表明,CPI及其肽段的显著抗氧化活性,使得其具有制备抗氧化功能食品和保健品的应用前景。     

短瓣金莲花种子无菌萌发与幼苗快繁技术初探

以野生短瓣金莲花种子为材料,探讨不同处理方式对种子发芽的影响,并比较不同培养基类型及激素组合对短瓣金莲花根茎部位形成的愈伤组织、不定芽增殖及生长的影响,建立无菌播种及组培快繁体系,为短瓣金莲花快繁和规模化生产提供技术支撑。结果表明：（1）用600 mg·L^-1 GA₃溶液浸泡48 h后并用0.1% HgCl₂溶液灭菌20 min的种子发芽效果最好;（2）适宜于增殖的培养基配方为MS+0.5 mg·L^-1 6-BA+0.1 mg·L^-1 NAA;（3）适宜于生根的培养基配方为不添加激素的MS。     

濒危植物毛瓣金花茶与其同属广布种茶光合特性的比较

毛瓣金花茶为山茶科山茶属植物,该研究分别对野生种群和栽培种群的毛瓣金花茶及其同属广布种茶的光合特性进行了测定及差异比较。结果表明:在野生和栽培环境下,毛瓣金花茶的光补偿点(LCP)(分别为1.17和3.87μmol·m-2·s-1)和光饱和点(LSP)(分别为395.8和423.6μmol·m-2·s-1)均较低,最大净光合速率(Pmax)(分别为4.25和3.91μmol·m-2·s-1)较小,是典型的阴生植物;而茶的LCP(分别为6.57和9.09μmol·m-2·s-1)较低,LSP(分别为765.0和809.6μmol·m-2·s-1)较高,Pmax(分别为9.37和9.75μmol·m-2·s-1)较大,为耐荫植物。野生和栽培的毛瓣金花茶的Pmax、表观量子效率(AQY)、最大羧化速率(Vcmax)、最大电子传递速率(Jmax)和潜在最大净光合速率(Pmax)均显著低于茶(P0.05),这表明毛瓣金花茶的光合能力和CO2利用能力都比茶要弱。栽培的毛瓣金花茶叶片的Chla、Chlb、Chl(a+b)含量与茶相比无显著差异(P0.05),表明毛瓣金花茶较低的光合能力与其叶绿素含量无关。野生和栽培的毛瓣金花茶的叶面积与茶相比无显著差异(P0.05),而比叶重则显著高于茶(P0.05),与茶相比,毛瓣金花茶对光强的适应范围狭窄,光合能力和CO2利用能力低下,这可能是其分布狭窄的重要生理原因。     

斯勒卷瓣兰，中国云南南部兰科一新种（英文）

描述并绘制了云南南部兰科石豆兰属一新种：斯勒卷瓣兰(Bulbophyllum dresslerianum Z. D. Han & H. Wang)。该新种属于双叶卷瓣兰组(section Tripudianthes Seidenf.),在形态上与该组的4种,即狄氏卷瓣兰(B. dickasonii)、堪布里石豆兰(B. kanburiense)、皱掌卷瓣兰(B. rugosisepalum)和拟双叶卷瓣兰(B. tripudians)近似,主要区别在于该种唇瓣前缘具囊泡,侧面及腹面被稀疏的短腺毛;侧萼片棕黄色,表面光滑。编制了斯勒卷瓣兰及其近缘种的检索表。目前,该种仅在云南南部墨江县发现一个居群,濒危状况有待评估。     

中国黄耆属一新种

多年生草本,高2—5厘米,密被开展的中着叉状毛。根木质化,直伸,灰褐色。茎极短缩,不明显。奇数羽状复叶,长3—4厘米,具短叶柄,有小叶10—13对;小叶椭圆形,灰绿色,长4—5毫米,两面被开展的毛,下面毛较密;托叶下半部合生,上部披针形,被开展的毛。总状花序具与叶近等长的总梗,密被开展的长毛。有花3—4朵;苞片披针形,有毛;萼筒状,不膨大,长约1厘米,被开展的白色长毛和混生少量的黑毛,萼齿钻状。长为萼筒的1/2;花冠黄色,旗瓣片近提琴形,长约2厘米,近顶部稍狭,顶端微凹,中部缢缩,下部渐狭成瓣柄,翼瓣与旗瓣近等长,瓣片长圆形,下部有耳,较瓣柄短;龙骨瓣短于翼瓣,瓣柄显著长于瓣片;二体雄蕊,子房线形,近于无柄,有毛;荚果未见。花期5——6月。本种与七叶黄耆A.heptapotamtuus     

自组装短肽对角膜碱烧伤的作用

目的研究自组装短肽材料1%RADAl6-I水溶液对大鼠和兔角膜碱烧伤的作用.方法用1 mol/L NaOH溶液造SD大鼠和兔角膜碱烧伤模型,左眼每口滴加短肽水凝胶10μ1(2次/d),右眼为空白对照.在烧伤后的不同时间段(7、10、14d)处死大鼠,第7 d处死兔,取角膜行HE染色,光学显微镜观察结果.结果短肽水凝胶治疗组角膜上皮重生较快,皮下纤维排列较好,空白对照组皮下仍有较大空洞,皮下纤维排列紊乱,说明短肽材料能促进角膜恢复.     

羊骨酶解液的植物乳杆菌发酵

为进一步提高羊骨酶解液的营养价值和生物利用度,探讨乳酸菌发酵对钙离子释放、短肽形成以及酶解液抗氧化活性的影响。首先从7株乳酸菌中筛选出了产蛋白酶能力最强的植物乳杆菌,接种羊骨酶解液,以发酵液中Ca~(2+)浓度为指标,响应面法优化得到发酵工艺:酶解液中添加1%的麦芽糖,调节起始pH为5.5,以4%接种量接种驯化好的植物乳杆菌,37℃摇床发酵14 h。发酵过程中,植物乳杆菌活菌数与Ca~(2+)含量(R=0.495,P0.01)和短肽得率(R=0.655,P0.01)呈极显著正相关,而多肽生成量与短肽得率呈负相关(R=–0.013)。发酵液中的Ca~(2+)浓度(P0.05)、水解度(P0.01)、短肽得率(P0.01)、羟脯氨酸含量(P0.01)均显著高于酶解液(P0.01),植物乳杆菌活菌数达到94.6×10~8 CFU/m L。发酵还可使酶解液对DPPH、·OH、O_2~-·三种自由基的清除能力显著提高(P0.01,P0.05)。综上所述,以植物乳杆菌发酵羊骨酶解液可进一步促进骨钙的转化和胶原短肽的生成并显著提高其体外抗氧化能力,短肽和Ca~(2+)反过来促进植物乳杆菌的繁殖,增强了酶解液的益生功能,乳酸菌产生的维生素、胞外多糖等物质使羊骨酶解液更富营养。     

Cyclopeptides from Sagina japonica (Caryophyllaceae)

Two new cyclic peptides, named sajaponicin C (1) and sajaponicin D (2), were isolated from the whole plants of Sagina japonica (Caryophyllaceae). Their structures were determined as cyclo(Pro(2)-Leu(2)-Tyr-Leu(1)-Phe(1)-Pro(3)-Phe(2)-Pro(1)) (1) and cyclo(Pro(1)-Pro(2)-Pro(3)-Pro(4)-Phe(1)-Gly-Thr-Ser-Phe(2)-Ile-Tyr) (2) on the basis of spectroscopic data, especially by two-dimensional (2D) NMR techniques.     

Two-dimensional proton NMR studies on poly(VPGVG) and its cyclic conformational correlate, cyclo(VPGVG)3

Two-dimensional nuclear Overhauser enhancement (2D NOESY) data are reported for the polypentapeptide of elastin, poly(VPGVG), and the cyclopentadecapeptide, cyclo(VPGVG)3. In both, the repeating type II Pro2-Gly3 beta-turn can be derived from the NOE data, providing confirmation of many previous studies. In addition, other through-space connectivities are detailed that also compare favorably with previously determined crystal and solution structures for cyclo(VPGVG)3. Also, near identical data for the cyclopentadecapeptide and the polypentapeptide demonstrate the cyclic conformation-linear (helical) conformational correlate relationship between the two molecules. The 2D NOESY experiment is seen to be an effective means of establishing the presence or absence of a conformational relationship between a cyclic repeating sequence and its higher molecular weight linear counterpart. This is an approach of substantial practical value when developing the conformation of sequential polypeptides and when attempting to identify the presence of the conformation of a repeating peptide sequence within a more complex primary structure. Having established the basic conformational relationship between a cyclic conformation and its linear helical counterpart, cross peaks present in the linear helical structure that are not present in the cyclic conformational correlate can provide information on the interactions between adjacent turns of the helix. In this connection, a Val gamma CH3 in equilibrium Pro beta CH2 interaction is reported that can be the basis for determining the number of pentamers per turn of helix once it is determined whether it is dominantly the Val1 or Val4 gamma CH3 that is interacting with the Pro2 beta CH2.     

多荚草中的新环肽

从石竹科植物多荚草（Polycarpon prostratum(Forssk.)Aschers.et Schwein.ex Aschers)中分离得到2个新的环肽化合物polycarponinB和C(1,2)。它们的结构通过波谱方法分别鉴定为：cyclo(G-ly1-Val1-Leu1-Val2-Gly2-Leu2-Pro)和cyclo(-Pro1-Thr-Leu1-Pro2-Pro3-Val-Leu2-Phe）。     

Isolation and Characterization of Antimicrobial Cyclic Dipeptides from Pseudomonas fluorescens and Their Efficacy on Sorghum Grain Mold Fungi

This study was aimed at isolation and characterization of natural antifungal compounds for grain mold, a key parasitic fungal disease of sorghum. Pseudomonas fluorescens strain isolated from rhizosphere of groundnut crop was selected as a source. Its biocontrolling ability was assessed by testing some biochemical attributes such as phosphate‐solubilization, and HCN, NH₃, indole‐3‐acetic acid, and siderophore production. The strain showed positive result for all except indole‐3‐acetic acid, revealing its suitability for a further study. The antibiotic‐sensitivity pattern of the strain against 43 antibiotics was also established, which showed resistance to 15 antibiotics. The efficacy of P. fluorescens strain against grain mold was identified by dual culture technique. Hundred percent inhibition was found against Fusarium moniliforme, an important causative agent of this disease. The strain was fermented for secondary metabolites and extracted with AcOEt. Chromatographic separation of the extract yielded four known compounds, cyclo(L ‐Pro‐L ‐Phe) ( 1 ), cyclo(trans‐4‐hydroxy‐L ‐Pro‐L ‐Leu) ( 2 ), cyclo(trans‐4‐hydroxy‐L ‐Pro‐L ‐Phe) ( 3 ), and cyclo(Gly‐L ‐Pro) ( 4 ), which were characterized by spectral analysis and optical rotation. The crude extract, a mixture of 2 and 3 , and isolated 1 were proved to be significantly effective against grain mold fungi. This is the first report on production of these cyclic dipeptides by P. fluorescens and their antagonistic properties.     

Crystal structures of two cyclic pseudopentapeptides containing ψ[CH2S] and ψ[CH2SO] backbone surrogates

The solid state conformations of cyclo[Gly–Proψ[CH₂S]Gly–D –Phe–Pro] and cyclo[Gly–Proψ[CH₂–(S)–SO]Gly–D –Phe–Pro] have been characterized by X-ray diffraction analysis. Crystals of the sulfide trihydrate are orthorhombic, P2₁2₁2₁, with a = 10.156(3) Å, b = 11.704(3) Å, c = 21.913(4) Å, and Z = 4. Crystals of the sulfoxide are monoclinic, P2₁, with a = 10.662(1) Å, b = 8.552(3) Å, c = 12.947(2) Å, β = 94.28(2), and Z = 2. Unlike their all-amide parent, which adopts an all-trans backbone conformation and a type II β-turn encompassing Gly-Pro-Gly-D -Phe, both of these peptides contain a cis Gly¹-Pro² bond and form a novel turn structure, i.e., a type II′ β-turn consisting of Gly–D –Phe–Pro–Gly. The turn structure in each of these peptides is stabilized by an intramolecular H bond between the carbonyl oxygen of Gly¹ and the amide proton of D -Phe⁴. In the cyclic sulfoxide, the sulfinyl group is not involved in H bonding despite its strong potential as a hydrogen-bond acceptor. The crystal structure made it possible to establish the absolute configuration of the sulfinyl group in this peptide. The two crystal structures also helped identify a type II′ β-turn in the DMSO-d₆ solution conformers of these peptides. © 1993 John Wiley & Sons, Inc.     

17O, 14N and 15N n.m.r. studies of the Co2+ complexes of cyclo(Pro17O-Gly15N) and cyclo(Gly17O-Pro) in aqueous solution

The complexation of cyclo(Pro17O-Gly15N) and cyclo(Gly17O-Pro) with Co2+ ions has been studied by 17O, 14N and 15N n.m.r. spectroscopy in aqueous solution. 17O, 14N and 15N transverse relaxation times and chemical shifts were measured as a function of temperature. The 17O n.m.r. studies unequivocally demonstrate that the cobaltous ion binds to the peptide oxygen of both compounds. The hyperfine coupling constant and the peptide residence times were found to be A = -0.165 MHz and -0.145 MHz, tau m = 16, and 92 microseconds for cyclo(Pro17O-Gly15N) and cyclo(Gly17O-Pro), respectively. The 14N and 15N studies of labeled cyclo(Pro17O-Gly15N) do not indicate binding at either the Gly15N or the Pro14N site.     

Fatty acyl-gramicidin S derivatives with both high antibiotic activity and low hemolytic activity

In the present study, novel eight GS derivatives having the octanoyl-(Lys)(n)- moieties, cyclo{-Val-Orn-Leu-d-Phe-Pro(4β-NH-X)-Val-Orn-Leu-d-Phe-Pro-} {X=-H (1), and -(Lys)(n)-CO(CH(2))(6)CH(3)n=0 (2), 1 (3), 2 (4), and 3 (5)} and cyclo{-Val-Orn-Leu-d-Phe-Pro(4α-NH-X)-Val-Orn-Leu-d-Phe-Pro-} {X=-H (6), and -(Lys)(n)-CO(CH(2))(6)CH(3)n=1 (7), and 2 (8)} were synthesized. Among them, 4, 5 and 8 result the high antibiotic activity against both Gram-positive and Gram-negative microorganisms tested. In addition, 4 and 5 showed very low hemolytic activity compared with that of GS. Thus, the introduction of the excess amino groups and the fatty acyl moiety to the γ-NH(2) group of Pro(5) residue in GS molecule lowered the unwanted hemolytic activity and enhanced the desired antibiotic activity.     

New Minor Cyclic Peptides from Brachystemma calycinum (in English) CHENG

From the ethanol extract of the roots of Brachystemma calycinum D.Don, a Chinese folk herb, four new minor cyclic peptides namely brachystemin A, B, C and D (1-4) have been isolated. Their structures were established as cyclo (Pro¹-Phe-Leu-Ala¹-Thr-Pro²-Ala²-Gly)(1)、cyclo(Pro¹-Ala-Phe-Trp-Asp-Pro²-Leu-Gly)(2)、cyclo (Pro¹-Ile-Gly-Pro²-Val-Ala¹-Ala²-Tyr) (3) and cyclo (Pro-OMet-Trp-Ile-Gly-Ala-Leu-Asp) (T4) respectively by means of extensive spectral methods.     

Peptide conformation. 48. Conformation and biological activity of proline containing cyclic retro-analogues of somatostatin

Six cyclic retro-analogues of the peptide hormone somatostatin have been synthesized using the solid phase technique. The peptides cyclo(-Xaa1-Phe2-Thr3-Lys4-Ybb5-Phe6-) and cyclo(-Phe1-Xaa2-Thr3-Lys4-Ybb5-Phe6-) with Xaa = D- or L-Pro and Ybb = D- or L-Trp were cyclized via the azide method. The conformations of the cyclic hexapeptides in DMSO-d6 solution were determined by a number of homo- and heteronuclear two-dimensional n.m.r.-techniques including 2D rotating frame NOE-spectroscopy. Two-step coherence transfers, ROE and chemical exchange, are observed for the first time in ROESY spectra. The backbone conformation of the all-trans cyclopeptides consists of a beta-turn containing the Pro residue in the position i + 1. These retro-analogues of somatostatin exhibit a high activity in the inhibition of cholate and phalloidin uptake by liver cells (cytoprotective effect); however, the hormonal activities of the natural hormone are completely suppressed. The constitutional and conformational requirements for the cytoprotective activity are discussed.