ISOLATION, STRUCTURE ELUCIDATION AND SYNTHESIS OF A NEW PRENYLATED FLAVONOL, MAACKIAFLAVONOL, FROM MAACKIA TENUIFOLIA

A new prenylated flavonol, maackiaflavonol, was isolated from the ethanol extract of the roots of Maackia tenuifolia. Its structure was elucidated as 7-hydrox-8-prenylflavonol by means of spectroscopic analysis (UV, IR, MS, NMR and 1H-1H COSY) and confirmed by total synthesis.

ISOLATION AND STRUCTURE ELUCIDATION OF A NOVEL STEROL FROM THE SOUTH CHINA SEA SPONGE DYSIDEA SP.

A novel and unusual sterol with unsaturation in the△^(5(14)) position,5α-cholesta-8(14),24(25)-diene-3β,6α-diol 1,was isolated from the South China Ses sponge Dysidea sp.The structure and relative stereochemistry of 1 was established by spectral analysis and comparison to the spectral data of known sterols.

Isolation and Structure Elucidation of an Antifungal Antibiotics A73 Produced by a Soil Fungus Strain No.131

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THE STRUCTURE ELUCIDATION OF A NEW BIS-ENTKAURANE COMPOUND, ISODOPHARICIN E, ISOLATED FROM ISODON PHARICUS (PRAIN) MURATA.

On the basis of spectroscopic evidence (MS, ~1HNMR, ^(13)CNMR, CD, ~1H-~1H and ~1H-^(13)C cosy NMR) and chemical synthesis, the structure of isodopharicin E (1), isolated from the dry leaves and tender branches of Isodon pharicus (Prain) Murata was elucidated as 3R, 3'R, 13S, 13'S-tetrahydroxy-11S, 11'S-diacetoxy(16S-O-15')-bisentkaur-15'-en-15-one.

STUDIES ON THE CHEMICAL CONSTITUENTS OF CLAUSENA LANSIUM(LOUR.)SKEELS Ⅲ.The structural elucidation of homo-and zeta-clausenamide(1)

The structures of two novel lactams isolated from Clausena lansium were elucidated mainly on the bases of their spectral data. They are homoclausenamide(1),a -lactam,and zetaclausenamide(4), an eight-membered ring lactam.

Toward Elucidating the Structure of Tetraploid Cotton Genome

Upland cotton has the highest yield,and accounts for >95% of world cotton production.Decoding upland cotton genomes will undoubtedly provide the ultimate reference and resource for structural,functional,and evolutionary studies of the species.Here,we employed GeneTrek and

STUDIES ON THE CHEMICAL CONSTITUENTS OF CLAUSENA LANSIUM (LOUR.) SKEELS Ⅳ THE STRUCTURAL ELUCIDATION OF SECO-AND SECODEMETHYL-CLAUSENAMIDE

The spectral data and chemical properties of two new amides isolated from Clausena lansium led to the assignment of acyclic structures of C-6 and C-7. The absolute configurations of the two chiral carbons in C-6 were determined by degradation to be 3S4R.

Isolation and structural elucidation of the compounds from the fruits of Camptotheca acuminate

The fruit of Camptotheca acuminate is used as a traditional Chinese medicine.Eight compounds were isolated from the fruit of Camptotheca acuminate for the first time,including(+)-(S)-abscisic acid(1),blumenol A(2),(E)-3-hydroxymegastigm-7-en-9-one(3),(-)-(3R)-3,5-dimethyl-8-methoxy-3,4-dihydroisocoumarin(4),(-)-(3R)-8-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one(5),neocnidilide(6),(3S)-butylphthalide(7)and senkyunolide I(8).Their structures were determined by comprehensive spectroscopic methods,including HRESIMS and 1D NMR.

(+)/(-)-Gerbeloid A,a pair of unprecedented coumarin-based polycyclic meroterpenoid enantiomers from Gerbera piloselloides:Structural elucidation,semi-synthesis,and lipid-lowering activity

A pair of coumarin-based polycyclic meroterpenoid enantiomers(+)/(-)-gerbeloid A[(+)-1a and(-)-1b]were isolated from the medicinal plant Gerbera piloselloides,which have a unique caged oxatricyclo[4.2.2.0^(3,8)]decene scaffold.Their planar and three-dimensional structures were exhaustively characterized by comprehensive spectroscopic data and X-ray diffraction analysis.Guided by the hypothetical biosynthetic pathway,the biomimetic synthesis of racemic 1 was achieved using 4-hydroxy-5-methylcoumarin and citral as the starting material via oxa-6πelectrocyclization and intramolecular[2+2]photocycloaddition.Subsequently,the results of the biological activity assay demonstrated that both(+)-1a and(-)-1b exhibited potent lipid-lowering effects in 3T3-L1 adipocytes and the high-fat diet zebrafish model.Notably,the lipid-lowering activity of(+)-1a is better than that of(-)-1b at the same concentration,and molecular mechanism study has shown that(+)-1a and(-)-1b impairs adipocyte differentiation and stimulate lipolysis by regulating C/EBPα/PPARγsignaling and Perilipin signaling in vitro and in vivo.Our findings provide a promising drug model molecule for the treatment of obesity.

Residual Dipolar Couplings in Structure Determination of Natural Products

The determination of natural products stereochemistry remains a formidable task.Residual dipolar couplings(RDCs)induced by anisotropic media are a powerful tool for determination of the stereochemistry of organic molecule in solution.This review will provide a short introduction on RDCs-based methodology for the structural elucidation of natural products.Special attention is given to the current availability of alignment media in organic solvents.The applications of RDCs for structural analysis of some examples of natural products were discussed and summarized.Graphical Abstract This review provides a short introduction on RDCs-based methodology for the structural elucidation of natural products.Special attention is given to the current availability of alignment media in organic solvents.The applications of RDCs for structural analysis of some examples of natural products were discussed and summarized.

Crystal Structure and Characterization of a Novel Neodymium Coordination Compound Based on Dawson Cluster

A new coordination compound, [{Nd(NMP)_2(H_2O)_6Cl}{Nd(NMP)_2(H_2O)_7}H (P_2Mo_(18)O_(62)) (NMP=N-methyl-2-pyrrolidone) was synthesized and characterized by elemental analyses, IR spectrum, and X-ray single crystal structural analysis. The crystal structure indicates that the title compound belongs to monoclinic space group C _c, with unit cell dimensions a =2.4528(5) nm, b =1.9495(4) nm, c =2.4405(5) nm, β =109.94(3)°, Z =4, V =10.970 (4) nm^3, D _c=2.262 g·cm^(-3), R 1=0.0676, wR 2=0.1441. The ESR spectrum of powder of the title compound at 110 K after being exposed to sunlight shows the signal of Mo^(5+), g =1.95. Cyclic voltammetry was measured in aqueous solution containing 0.1 mol·L^(-1) KCl as the supporting electrolyte and shows that the title compound undergoes two one-electron reversible reductions.

一株球毛壳霉次级代谢产物及其体外抗肿瘤活性研究

目的研究球毛壳霉次级代谢产物及其体外抗肿瘤活性。方法2021年3—12月,采用硅胶柱色谱法、凝胶柱色谱法、半制备高效液相色谱法等分离方法和技术对球毛壳霉次级代谢产物进行分离纯化,使用NMR核磁数据及质谱数据分析鉴定化合物的结构;采用MTT法评价化合物的体外抗肿瘤活性。结果从球毛壳霉次级代谢产物中分离得到7个化合物,分别鉴定为(1)cyclo-(L-Leu-L-Trp),(2)N-acetyl-L-tryptophan,(3)N-acetyltryptamine,(4)armochaetoglobin G,(5)armochaetoglobin J,(6)armochaetoglobinK,(7)chaetoglobosinU;化合物1和3为首次从球毛壳霉中分离得到;化合物4和5对选定的人肿瘤细胞具有一定的体外抗增殖活性,IC_(50):12.58~35.28µmol/L。结论球毛壳霉能够产生结构丰富的代谢产物,其中一些代谢产物有良好的抗肿瘤活性,具有潜在药用价值,其活性化合物有待进一步挖掘。

怀山药内生真菌Chaetomium sp.的次生代谢产物研究

以一株怀山药内生毛壳菌Chaetomium sp.L-45为研究对象,对其次生代谢产物进行分离和结构鉴定。对毛壳菌进行大米发酵,通过硅胶柱色谱、Sephadex LH-20、半制备高效液相色谱等分离技术分离发酵物的乙酸乙酯提取物,利用NMR、HR-ESI-MS等波谱解析技术进行化合物的结构鉴定。从目标菌株的乙酸乙酯提取物中分离得到4个化合物,分别鉴定为3,4-二甲氧基-5-羟基-6-丙基-苯甲酸(1)、5-异戊烯基-吲哚-3-羧酸(2)、lecanorin(3)和麦角甾醇(4),其中,化合物1为新化合物,化合物2和3系首次从毛壳菌属真菌中分离得到。

西沙马尾藻共附生真菌Aspergillus sp.SYPUF41304次级代谢产物的分离与鉴定

目的对西沙马尾藻共附生真菌Aspergillus sp.SYPUF41304的次级代谢产物进行分离与鉴定。方法利用硅胶柱色谱、凝胶柱色谱、中压反相柱色谱及半制备高效液相色谱等分离手段对马尾藻共附生真菌Aspergillus sp.SYPUF41304的液体发酵提取物进行分离纯化,并利用核磁共振、质谱等波谱学方法,结合文献对照,确定化合物结构。结果最终从提取物中分离得到10个化合物,经鉴定为吲哚-3-甲醛(1H-indole-3-carboxaldehyde)(1)、吲哚-3-乙酸甲酯(methyl indole-3-acetate)(2)、环(L-脯氨酸-L-缬氨酸)(cyclo-L-prolyl-L-valine)(3)、brevianamide F(4)、asperterreusine A(5)、talaisocoumarin A(6)、3-甲基-6-羟基-8甲氧基-3,4-二氢异香豆素(3-methyl-6-hydroxy-8-methoxy-3,4-dihydroisocoumarin)(7)、3-甲氧基-6,8-二羟基-3-甲基-3,4-二氢异香豆素(3-methoxy-6,8-dihydroxy-3-methyl-3,4-dihydroisocoumarin)(8)、4-hydroxykigelin(9)和de-O-methyldiaporthin(10)。结论化合物按结构类型可分为生物碱和聚酮类等,化合物4~8均为首次从该属真菌中分离得到。所有化合物在4 mg·mL^(-1)浓度下,均未显示出抗细菌活性。

海洋真菌Aspergillus sp.LW152抗细菌活性代谢产物研究

目的对海洋真菌Aspergillus sp.LW152发酵提取物的抗细菌成分进行研究。方法利用硅胶柱层析、葡聚糖凝胶Sephadex LH-20柱层析、半制备高效液相色谱等方法,对该菌株发酵提取物进行分离纯化;化合物结构通过核磁共振波谱(NMR)、质谱(MS)等数据并与文献数据对比进行确定;采用微量肉汤稀释法对化合物抗菌活性进行体外评价。结果从真菌LW152发酵的乙酸乙酯提取物中分离得到了7个化合物,其结构分别鉴定为7-脱氧-7,14-二脱氢水杨酸(1)、7-脱氧-7,8-二脱氢水杨酸(2)、pseudaboydin B(3)、(Z)-5-(羟甲基)-2-(6'-甲基庚-2'-烯-2'-基)苯酚(4)、aspergillusene A(5)、2,4-二羟基-6-甲基苯甲酸甲酯(6)和1-亚油酸单甘油酯(7)。结论海洋真菌Aspergillussp.LW152能产生具有抗细菌活性的次级代谢产物,其中化合物4和5对6种致病细菌的生长均具有一定的抑制作用,化合物7对青枯雷尔菌的生长具有抑制作用。

Chalcone derivatives as novel,potent and selective inhibitors against human Notum:Structure–activity relationships and biological evaluations

Human Notum(hNotum)inhibitors could be used for treating Wnt signalling-associated diseases including colorectal cancer.Herein,two series of chalcone derivatives were designed and synthesized aiming to find selective and potent hNotum inhibitors.Structure–activity relationship(SAR)studies showed that 2-methoxyl and 5-bromine substitutions on A-ring significantly enhanced anti-hNotum effect,while 4’-ethoxyl and 3’-alkyl substitutions on B-ring were beneficial for hNotum inhibition.Among all tested chalcones,B11 displayed the most potent anti-Notum effect(IC_(50)=3.6 nmol/L),good selectivity,excellent chemical stability and suitable metabolic stability.Further investigations showed that B11 acted as a competitive inhibitor of hNotum,while this agent(5μmol/L)significantly weaken the migration abilities of colorectal cancer cells.Collectively,this study deciphers the SARs of chalcones as hNotum inhibitors and reports a novel and potent hNotum inhibitor with the anti-migration effect on colorectal cancer cells,which offers a promising lead compound to develop novel anti-cancer agents.

房山紫堇地上部分化学成分及其抗乳腺癌细胞增殖作用研究

对房山紫堇Corydalis fangshanensis地上部分化学成分及其体外抗乳腺肿瘤细胞活性进行研究。采用各种色谱分离技术对乙酸乙酯和正丁醇两个萃取部位进行系统分离纯化,通过多种波谱数据(1D、2D NMR、MS、IR、UV)鉴定化合物结构,从房山紫堇乙酸乙酯和正丁醇两个部位中鉴定了17个化合物,分别为7-acetyl thalifoline(1)、pycnarrhine(2)、corynoxidine(3)、trans-isocorypalmine N-oxide(4)、四氢巴马汀(5)、四氢药根碱(6)、liriotulipiferine(7)、异波尔定碱(8)、乌药碱(9)、脱氢甲卡维丁(10)、feruloylputrescine(11)、木黄酮(12)、二甲基咖啡酸(13)、4-羟基-3-甲氧基桂皮酰基-β-D-葡萄糖苷(14)、水仙苷(15)、丁香脂素-4-O-β-D-葡萄糖苷(16)、异落叶松脂醇9-O-β-D-葡萄糖苷(17)。其中化合物1作为天然产物首次报道,2~17是首次从房山紫堇中分离得到。结合体外MTT法评价单体化合物对人乳腺癌肿瘤细胞(MDA-MB-231、MCF-7)抑制作用。结果显示化合物2~10、13、15~17对MDA-MB-231细胞有一定的抑制作用,其IC 50值范围为8.00~79.99μmol/L,化合物2~10、16、17对MCF-7细胞有抑制作用,IC 50值范围为7.29~86.91μmol/L。

双氢链霉素未知杂质的结构确证与限值设定

为了科学制定双氢链霉素产品中未知杂质的限度标准,从分子结构、来源和质量稳定性等3个方面开展研究。首先,采用制备色谱仪从双氢链霉素产品中制得杂质纯品,借助液相色谱-高分辨质谱(LC-HRMS)和核磁共振谱(NMR)进行波谱分析、研究杂质分子结构;其次,采用高效液相色谱法(HPLC),结合双氢链霉素生产过程开展杂质来源考察;最后,设计了多条件的影响因素实验,考证杂质的稳定性。结果表明:杂质分子结构与双氢链霉素的分子结构类似,同属氨基糖苷类物质;杂质来源于双氢链霉素发酵阶段产生的链霉素类似物,类似物在氢化过程被同步还原成为产品中的杂质;杂质对酸、碱、高温、氧化、光照等因素不敏感,具有较好的稳定性。由链霉素发酵代谢产生的相关性杂质稳定性较好,设定其限度标准为≤1.0%(峰面积分数)是安全、合理的,可为临床用药提供重要参考。

海博麦布结构确证

本文采用紫外吸收光谱、红外吸收光谱、质谱、核磁共振波谱(包含^(1)HNMR、^(13)CNMR、DEPT、^(1)H-^(1)H COSY、^(1)H-^(1)HNOESY、^(1)H-^(13)CHSQC和^(1)H-^(13)CHMBC)以及单晶衍射等方法对海博麦布进行结构分析,对其所有的^(1)HNMR和^(13)CNMR谱信号进行了归属,还通过差示扫描量热法、热重分析及粉末X-射线衍射分析对海博麦布晶型进行研究.

云南蓍地上部分化学成分分离与结构鉴定

针对药用植物云南蓍的化学成分进行分离与结构鉴定,采用正相硅胶、反相硅胶(Rp-C18)、葡聚糖凝胶(Sephadex LH-20)、MCI以及RP-HPLC色谱等几种分离手段,对该药用植物地上部分的90%乙醇提取浸膏进行分离纯化,依据现代波谱方法(核磁共振NMR、质谱MS)以及理化性质对分离得到的单体化合物的结构进行确定。最终从该植物中分离并鉴定了9个单体化合物,结构分别为matricarin(1)、3β-hydroxy-11α,13-dihydro-costunolide(2)、黑麦草内酯(3)、4-羟基-3-甲氧基苯乙酮(4)、2-苯基乙酰胺(5)、sylvamide(6)、5-羟甲基呋喃甲醛(7)、6-甲氧基-7-羟基香豆素(8)、邻苯二甲酸二丁酯(9)。这些化合物中,化合物1~8为首次从该植物中分离得到。