A new tigliane-type diterpene ester from <Emphasis Type="Italic">Wikstroemia scytophylla</Emphasis>

A new tigliane-type diterpene ester, wiksphyllamin B (1), and one known compound, 12-O-benzoylphorbol 13-octanoate (2), were isolated from the stems of Wikstroemia scytophylla Diels. Their structures were identified using spectroscopic methods. The incorrect assignment of ¹³C NMR data of compound 2 in the literature was revised according to the 2D NMR spectra.     

Geometric Isomers of Cobalt(II) and Cobalt(III) Picolinates in Solution

Cobalt complexes with picolinic acid (HPic), namely, [Co^II(Pic)₂(H₂O)₂] · 2H₂O (I) and [Co^III(Pic)₃] · H₂O (II) are studied using ¹H and ¹³C NMR spectroscopy. Compound Iexists in solution as three geometric isomers, namely, trans-trans-trans, cis-trans-cis, and trans-cis-cis(molar ratio 4 : 2 : 1, respectively). According to ¹³C NMR data, compound IIexists in solution as a mer-isomer. The relative energy stability of the isomers was estimated using the molecular mechanics method.     

Novel Synthesis and Characterization of 1,3‐Bis(2‐dihydrothiazolyl)thiaalkoxy‐p‐tert‐butylcalix[4]arenes

A novel series of 1,3‐bis(2‐dihydrothiazolyl)thiaalkoxy‐p‐tert‐butylcalix[4]arenes generated by the reaction between 4,5‐dihydrothiazole‐2‐thiol and the different dibromide calix[4]aryl groups have been synthesized and structurally characterized by IR, ¹H NMR, ¹³C NMR, and MS. From their analytical data, it was found that compounds 8, 9, and 10 had cone conformations, whereas compound 11 existed as a mixture conformation. To verify the structure of the synthetic compounds, a single‐crystal X‐ray structure of compound 8 was obtained.     

Determination of a new chromone from Aurantii Fructus Immaturus by DFT/GIAO method

Investigation of EtOAc fraction from the 95% ethanol extract of Aurantii Fructus Immaturus led to the isolation of one new chromone (1) and seven known flavonoids (2–8). Their structures were elucidated mainly by NMR and HR-ESI-MS, as well as on comparison with the reported NMR data. The final substituent pattern of 1 was defined by comparison of ¹³C NMR data calculated by DFT/GIAO with those of experimental NMR data.     

柔荑软珊瑚Nephthea sp.中两种具有细胞毒活性的甾醇化合物

采用抗肿瘤活性追踪法对采自中国南海西沙群岛永兴岛柔荑软珊瑚Nephthea sp.中抗肿瘤活性成分进行研究, 报道了两种具有细胞毒活性的甾醇化合物, 经过MS, IR, ¹H NMR, ¹³C NMR (DEPT), HSQC 和HMBC等光谱技术鉴定为: 24-甲基胆甾-5-烯-3β,8β-二醇(1)和24-亚甲基胆甾-4-烯-3β,6β-二醇(2), 化合物1为新化合物, 利用X-ray单晶衍射技术验证化合物2的立体结构. 化合物1对肝癌细胞(BEL-7402), 小鼠白血瘤细胞(P₃₈₈)和人结肠癌细胞(LOVO)作用的IC₅₀值分别为18.0, 25.5和20.6 μg/mL; 化合物2对肿瘤细胞P₃₈₈和人乳腺癌细胞(MCF)作用的IC₅₀值分别为1.0和2.5 μg/mL.     

中国红树植物木榄Bruguiera gymnorrhiza中新颖罕见多聚二硫大环化合物的结构研究

通过对采自湛江红树林植物木榄(Bruguiera gymnorrhiza)中化学成分的系统研究, 从中分离得到5个聚二硫化合物. 经现代波谱学分析(IR, ¹H NMR, ¹³C NMR, 2D NMR, MS等), 鉴定其中1个化合物是结构新颖的多聚二硫大环化合物, 命名为木榄八硫醇(neogymnorrhizol, 1), 该化合物是由4个重复的2-羟基-1,3-丙二硫醇基聚合而成的二十元大环分子; 此外还分离得到了4个已知聚二硫化合物, 它们分别为木榄六硫醇(gymnorrhizol, 2a)、新木榄二硫醇(bruguiesulfurol, 3)、木榄二硫醇(brugierol, 4)和异木榄二硫醇(isobrugierol, 5). 其中化合物3的立体化学结构经过X单晶衍射并与文献对照得以确定, 在此基础上重新对化合物4和5的核磁共振信息进行全归属; 同时修订了文献中对化合物4立体化学结构的表述. 探讨了聚二硫化合物可能的生物合成途径, 分析了化合物1～5可能的相互间的生源关系; 经体外生物活性测试研究发现, 化合物2a和3均对II型糖尿病靶标分子人蛋白酪氨酸磷酸酯酶(hPTP1B)具有显著的抑制活性.     

Nine sesquiterpenes from Solanum torvum

Three new sesquiterpenes, namely 3β,11-dihydroxy-4,14-oxideenantioeudesmane (1), 1β,10β,12,14-tetrahydroxy-allo-aromadendrane (2) and 1β,10β,13,14-tetrahydroxy-allo-aromadendrane (3), along with six known sesquiterpenes (4–9), were isolated from the roots of Solanum torvum. Compound 4 and 5 are epimers, their main difference lies in the C-11 configulation. Normally, epimers do not make a huge difference in C NMR spectra, but in this kind of structure of A, B, C rings, and C ring is sterically strained structure, stericall effects influence strongly the ¹³C NMR chemical shifts, when C-11 configulation changed, it makes a huge difference in the three ring of structure, such as C-6, C-7, C-11. New compound 2 and 3 are epimers and similar to compound 4 and 5, their just increase a hydroxy in C-1 and have a same regular pattern in C NMR spectra, otherwise, compound 5 was firstly confirmed by single-crystal X-ray diffraction.     

主客体包结法选择分离青花椒挥发油中的化学成分

以1,1,6,6-四苯基-2,4-己二炔-1,6-二醇为主体分子, 可简单、迅速地从青椒挥发油中选择分离出化学成分烯丙基茴香醚, 基于挥发油的用量, 收率为3.78%. IR, ¹H NMR, ¹³C NMR光谱和单晶衍射证实了包结化合物结构, 用气相色谱法评价了选择分离效果, 分离的烯丙基茴香醚气相色谱纯度为94.5%. 同时, 主体分子形成的隧道框架对茴香醛具有识别作用, 形成2∶1(主/客)物质的量比的特殊结构包结物晶体, 它是主客体分子物质的量比为1∶2包结物的超分子异构体.     

Synthesis,spectral, stereochemical and biological evaluation of (E)-2-(3-pentyl-2,6-diarylpiperidin-4-ylidene)-N-phenylhydrazinecarbothioamide derivatives

A series of new (E)-2-(3-pentyl-2,6-diarylpiperidin-4-ylidene)-N-phenylhydrazinecarbothioamides (1-6) were synthesized from the corresponding 3-pentyl-2,6-diarylpiperidine-4-ones condensation with phenyl thiosemicarbazide. Their chemical structures were confirmed by means of elemental analysis, FT-IR, ¹H, and ¹³C NMR spectral techniques and for compound 3, HOMOCOSY, HSQC, HMBC, NOESY, and DEPT NMR spectral techniques. From the NMR spectral data the compounds (1-6) are shown to exist in normal chair conformation with equatorial orientation of all the phenyl groups at C-2 and C-6 and pentyl group at C-3. The synthesized compounds were screened for their bacterial activity against Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi, and Escherichia coli and fungal activity against Candida albicans, Rhizopus sp, Aspergillus niger, and Aspergillus flasvus.     

玉米须中的一个新黄酮和两个尿素苷

玉米须是我国传统中药, 具有多种生物活性. 为了寻找玉米须中的生物活性成分, 对玉米须的化学成分进行了研究, 从中分离得到一个新黄酮1和两个尿素苷2和3. 应用多种波谱学方法(¹H NMR, ¹³C NMR, HSQC, HMBC, ¹H-¹H COSY, ESI-MS等), 确定了3个化合物的化学结构. 化合物1为新化合物, 鉴定为6-乙酰基-木犀草素; 化合物2和3是两个新的天然产物, 分别鉴定为鼠李糖尿素苷和1,3-二鼠李糖尿素苷. 首次对两个新天然产物的氢谱和碳谱数据进行了全归属.     

Godavarin K: a New Limonoid with an Oxygen Bridge between C(1) and C(29) from the Godavari Mangrove Xylocarpus moluccensis

Godavarin K ( 1 ), a new limonoid with an oxygen bridge between C(1) and C(29), was obtained from seeds of an Indian mangrove, Xylocarpus moluccensis, together with a known tetranortriterpene, 6‐de(acetyloxy)‐7‐deacetylchisocheton compound E (=(5α,7α,13α,17α)‐7‐hydroxy‐4,4,8‐trimethyl‐3‐oxocarda‐1,14‐dienolide; 2 ). The structure of godavarin K was established on the basis of spectroscopic data. In addition, the confusion of ¹H‐ and ¹³C‐NMR data for compound 2 in previous literature was clarified.     

Spectroscopic characterization and <Emphasis Type="Italic">Ab initio</Emphasis> calculations of new diazaphosphole and diazaphosphorinane

Phosphoryl chloride is used as a starting material to synthesize new diazaphosphole, (1) and diazaphosphorinane, (2). The products are characterized by ¹H, ¹³C, ³¹P NMR, and IR spectroscopy. A high value ² J(PNH) = 17.0 Hz, 17.2 Hz is measured for two non-equivalent NH protons of endocyclic nitrogen atoms in compound 1, while it greatly decreases to 4.5 Hz in 2. Also, great amounts are obtained for two ² J(P,C) as well as two ³ J(P,C) in the ¹³C NMR spectrum of 1, but they are zero in 2. Here, the effect of ring strain and ring size on the structural and spectroscopic parameters is observed. The ³¹P NMR spectra reveal that δ(³¹P) of compound 1 is far much more downfield (12.63 ppm) relative to that of compound 2 (−10.39 ppm). Furthermore, ab initio quantum chemical calculations are performed to optimize the structures of these molecules by density functional theory (B3LYP) and Hartree-Fock (HF) methods, using the standard 6−31+G** basis set. The stabilization energies are calculated by the equation ΔE _{stabilization} = E _molecule − ΣE _i , where i = atom. To obtain the atomic hybridizations, NBO computations are made at the B3LYP/6−31+G** level. Also, by NMR calculations the ¹H, ¹³C, ³¹P chemical shifts are obtained and compared with the experimental ones.     

Cytotoxic triquinane-type sesquiterpenoids from the endophytic fungus Cerrena sp. A593

Abstract

The culture broth of Cerrena sp. A593, which was isolated from Pogostemon cablin, showed potent cytotoxicity against several human tumor cell lines. The following chemical study resulted in the isolation of two new triquinane-type sesquiterpenoids, named cerrenins D (1) and E (2), along with two known compounds plerocybellone A (3) and chloriolin B (4). Their structures were fully assigned with the aid of extensive spectroscopic analysis (¹H and ¹³C NMR, HSQC, HMBC, ¹H-¹H COSY, HRESIMS, and IR) and data from the literature. Moreover, cytotoxic activity in vitro of compounds 1–4 were evaluated against SF-268, MCF-7, NCI-H460, and HepG-2 tumor cell lines. The new compound 1 exhibited weak growth inhibitory activity against all the four tumor cell lines with IC₅₀ values of 41.01, 14.43, 29.67, 44.32?μM.     

Antifungal activity against Botrytis cinerea of labdane-type diterpenoids isolated from the resinous exudate of Haplopappus velutinus Remy (Asteraceae)

Two labdane diterpenoids were isolated, from the resinous exudate of Haplopappus velutinus Remy (Asteraceae); the main compound was identified as 7,13-(E)-labdadien-15,18-dioic-acid-18-methyl ester (1) and the minor compound identified as 7-labden-15,18-dioic-acid-18-methyl ester (2). Their structures were obtained using FTIR, MS, HRMS and NMR data: 1D NMR (¹H, ¹³C and DEPT-135), 2D homonuclear NMR (COSY and NOESY) and heteronuclear NMR (HSQC and HMBC). The trans stereochemistry of the decalin moiety of compounds 1 and 2 was established through NOESY experiments of the reduction product of 1; 7-labden-15,18-diol (1a). Diterpenoids 1 and 1a are described for the first time and showed antifungal activity, inhibiting approximately 40% mycelial growth of Botrytis cinerea.     

A new alloside from <Emphasis Type="Italic">Neocheiropteris palmatopedata</Emphasis>

A new compound, 2,4,6-trihydroxybenzoic acid 4-O-β-D-allopyranoside (1), together with four known compounds, sucrose (2), fructose (3), ecdysterone (4), and β-sitosterol (5) was isolated from the roots of Neocheiropteris palmatopedata (Baker) Christ. The new compound was identified based on extensive spectroscopic studies including HR-ESI-MS, FAB-MS, ¹H NMR, ¹³C NMR, DEPT, ¹H–¹H COSY, HSQC, HMBC, and NOESY spectra, and the known compounds were identified by their spectroscopic data analysis, comparison with reports in the literature, and co-chromatography with authentic standards. Compounds 2, 3, and 5 were obtained from the Neocheiropteris genus for the first time, and 4 was originally isolated from the plant.     

Urea and thiourea derivatives of 3-(trifluoromethyl)-5,6,7,8-tetrahydro-[1, 2, 4]triazolo[4,3-a]pyrazine: Synthesis,characterization, antimicrobial activity and docking studies

Abstract

An efficient and robust synthetic procedure was developed primarily for the synthesis of a precursor compound; 3-(trifluoromethyl)-5,6,7,8-tetrahydro-[1, 2, 4]triazolo[4,3-a]pyrazine (11), from 2-chloropyrazine (7) through the chemical transformations such as hydrazine substitution, trifluoroacetyl group induction, cyclization and pyrazine ring reduction. A new series of urea derivatives 13a-e and thiourea derivatives 13f-j of compound 11 have been synthesized and the structures of all the compounds were confirmed using spectroscopic analyses such as IR, ¹H NMR, ¹³C NMR, LC-MS and HRMS. The newly synthesized compounds were screened for their in vitro antimicrobial activity against five bacteria and two fungi, in which compounds 13d, 13i and 13j displayed potential activity against bacterial strains and 13a, 13d, 13g and 13j against fungal strains with the MIC values in the range of 6.25–25.0 µg/mL. An overall comparison of the activity results revealed that thiourea derivatives contain better activity than that of urea compounds. Molecular docking studies on poly (ADP-ribose) polymerase 15 (ARTD7, BAL3) demonstrated that all the synthesized compounds possess significant binding energies (-8.1 to -9.8?kcal/mol) with no adverse effect in the active site of protein.     

Constituents of fruit pulp of <Emphasis Type="Italic">Maytenus salicifolia</Emphasis> and complete 1D/2D NMR data of 3<Emphasis Type="Italic">β</Emphasis>-hydroxy-D:B-friedo-olean-5-ene

A mixture of long-chain hydrocarbons constituted by nonacosane (29C, 7.5%), hentriacontane (31C, 48.3%), and tritriacontane (33C, 30.1%), the ester 1′-acetyloxymethylpentacosa-20′-enyl 10-hydroxydecanoate (2), β-amyrin (3), friedelin (4), and lupeol (5), and 3β-hydroxy-D:B-friedo-olean-5-ene (6) were identified as constituents of fruits of Maytenus salicifolia Reissek (Celastraceae). The structural formula and the stereochemistry of compound 6 were established by the data obtained through ¹H and ¹³C NMR spectroscopy, including DEPT-135 and 2D (HMQC, HMBC, and NOESY) experiments. By analysis of the spectral data, it was possible to correct seven chemical shift assignments of compound 6, which were erroneous attributed and published in the scientific literature.     

A novel naphthoquinone from <Emphasis Type="Italic">Plumbago zeylanica</Emphasis> roots

A novel naphthoquinone (1) was isolated from the methanol extract of P. zeylanica roots in addition to a known compound plumbagin (2). Their structures were determined by UV, IR, MS, ¹H, and ¹³C NMR spectroscopic analysis, including 2D NMR.     

Westerdijkin A,a new hydroxyphenylacetic acid derivative from deep sea fungus Aspergillus westerdijkiae SCSIO 05233

A new methyl 2-(4-((2-hydroxy-3-methylbut-3-en-1-yl)oxy)phenyl) acetate 1, together with five known compounds 2–6, was isolated from the culture of the deep sea-derived fungus Aspergillus westerdijkiae SCSIO 05233. The new structure was determined by NMR (¹H and ¹³C NMR, HSQC, HMBC and MS) and optical rotation analysis. Compound 5 displayed weak inhibitory activities towards K562 and promyelocytic HL-60 with IC₅₀ values of 25.8 and 44.9 μM, and compound 6 showed strong antifouling activity with EC₅₀ value 8.81 μg/mL.     

Synthesis,Structures, and Fungitoxicity of Novel Organophosphorus Compounds

Abstract

A series of biologically active organophosphorus compounds have been synthesized by the reactions of O,O-diethylchlorophosphate with Schiff bases derived from 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-oxadiazole and salicylaldehyde/2-hydroxyacetophenone. The compounds have been characterized on the basis of analyses and spectral (IR, ¹H, ¹³C NMR) data. Fungicidal activities of these derivatives against Colletotrichum falcatum, Fusarium oxysporum, and Curvularia pallescence have been evaluated. All compounds showed moderate to significant antifungal activity.