A phytochemical investigation of the flowers of Salvia miltiorrhiza Bunge led to the isolation of two new oleanane‐ and ursane‐type triterpenoids, (3α)‐olean‐12‐ene‐3,23‐diol ( 1 ) and (3α)‐urs‐12‐ene‐3,23‐diol ( 2 ), as well as of four known triterpenoids. Their structures were elucidated on the basis of spectroscopic evidence, including 1D‐ and 2D‐NMR, HR‐MS, and the X‐ray analysis, and by comparison with literature data. 相似文献
A practical synthetic route to various 2-alkylpropane-1,3-sultones, the key intermediates for the preparation of 2-substituted homotaurines as analogs of tramiprosate, was developed. 相似文献
The hydrodistilled essential oil composition from the aerial parts of Salvia macilenta (Lamiaceae) from Iran was analyzed by GC and GC-MS. The oil analysis confirmed the characterization of thirty-one compounds, accounting for 99.4% of the total oil. Analysis of the oil showed that the oil of S. macilenta was rich in monoterpene hydrocarbons with a-pinene (60%) as the main component followed by γ-elemene (6.1%), thymol (5.2%), elemol (4.7%), and β-caryophyllene (4.1%).__________Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 136–137, March–April, 2005. 相似文献
A new furan derivative named 3-(5-oxo-2,5-dihydrofuran-3-yl) propanoic acid (1) was isolated for the first time. Its structure was elucidated by UV, IR, NMR, HR-ESI-MS and the single-crystal X-ray diffraction spectroscopic data. Meanwhile, the antifungal and antibacterial activities of compound 1 was tested, it exhibited potent antifungal activity against Fusarium graminearum with MIC value of 16?µg/mL and medium antibacterial activity against Streptococcus lactis with MIC value of 32?µg/mL. 相似文献
Glycosides were isolated from the fruit of Camptotheca acuminata and identified using NMR, MS, UV and IR spectrometries. 10-O-(1-β-D-glycosyl) camptothecin (1) was identified for the first time in a natural material. In addition, compounds 2–4 were firstly reported from the fruits of C. acuminata and indentified as syringaresinol-4, 4′-O-bis-β-D-glucoside (2), hyperoside (3) and pumiloside (4), respectively. Two known compounds, vincoside-lactam (5) and strictosidinic acid (6), were also obtained. 相似文献
Here, the synthesis and the characterization of novel amphiphilic graft copolymers with tunable properties, useful in obtaining polymeric fluorescent nanoparticles for application in imaging, are described. These copolymers are obtained by chemical conjugation of rhodamine B (RhB) moieties, polylactic acid (PLA), and O‐(2‐aminoethyl)‐O′‐methyl poly(ethylene glycol) (PEG) on α,β‐poly(N‐2‐hydroxyethyl)‐d,l ‐aspartamide (PHEA). In particular, PHEA is first functionalized with RhB to obtain PHEA–RhB with a derivatization degree in RhB (DDRhB) equal to 0.55 mol%. By varying the reaction conditions, different amounts of PLA are grafted on PHEA–RhB to obtain PHEA‐RhB‐PLA with DDPLA equal to 1.9, 4.0, and 6.2 mol%. Then, PEG chains are grafted on PHEA‐RhB‐PLA derivatives to obtain PHEA‐RhB‐PLA‐PEG graft copolymers. The preparation of polymeric fluorescent nanoparticles with tunable properties and spherical shape is described by using PHEA‐RhB‐PLA‐PEG with DD in PLA and PEG equal to 4.0 and 4.9 mol%, by following easily scaling up processes, such as emulsion‐solvent evaporation and high pressure homogenization (HPH)‐solvent evaporation techniques.
An intramolecular Ugi reaction of 2-(2-formyl-1H-indol-1-yl)acetic acid with aryl amines and isocyanides has been developed to produce a novel class of N-alkyl-3-oxo-2-aryl-1,2,3,4-tetrahydropyrazino[1,2-a]indole-1-carboxamides in good yields. This is the first report on intramolecular Ugi three component reaction of 2-(2-formyl-1H-indol-1-yl)acetic acid, aryl amine, and isonitrile. 相似文献
Propyl O-(α-L-rhamnopyranosyl)-(1→3)-[2,4di-O-(2s-methylbutyryl)-α-L-rhamnopyranosyl]-(1→2)-(3-O-acetyl-β-glucopyranosyl)-(1→2)-β-D-fucopyranoside (1), the tetrasaccharide moiety of Ricolorin A, was synthesized in total 23 steps with a longest linear sequence of 10 steps, and overall yield of 3.7% from D-Glucose. The isomerization of the dioxolane-type benzylidene in the prance of NIS/AgOTf was observed. Tetrasaccharide 1 exhibited no activity against the cultured P388 cell as Tricolorin A did. 相似文献
The complexation of the natural antioxidants α‐lipoic acid (ALA) and its reduced form dihydrolipoic acid (DHLA) with Hg2+ was investigated by a recently proposed differential pulse voltammetric (DPV) method using the rotating Au‐disk electrode. Complexation processes are proposed from the multivariate curve resolution by alternating least squares (MCR‐ALS) analysis of DPV titration data. Main complexes were both 1 : 1 Hg : ALA and Hg : DHLA, although the formation of 1 : 2 complexes can be also deduced. ALA and DHLA show different Hg2+‐binding patterns at different pH. Voltammetric findings are completed with the data obtained by electrospray ionization mass‐spectrometry (ESI‐MS), especially in negative mode. 相似文献
A new benzofuran compound, named 2-[5-hydroxy-4-methoxy-2-(3-p-henyl-trans-allyloxy)benzyl]-5-hydroxy-6-methoxy-3-phenylbenzofuran (1), together with (+)-obtusafuran (2) and isoparvifuran (3), was isolated from the heartwood of Dalbergia latifolia. Their structures were elucidated by a combination of spectroscopic methods and comparison with the literature. Compounds 2 and 3 were obtained from this plant for the first time. Compound 1 exhibited moderated antioxidant effect for scavenging 1,1-diphenyl-2-picryhydrazyl (DPPH) free radical (IC50 = 96.7 ± 8.9 μM). 相似文献
Poly(alkylene phosphate)s bearing regularly distributed uracil moiety in the main chain have been obtained. The synthetic procedure consists of condensation of bis(diethylamino)-methoxyphosphine with N1,N3-bis(2′-hydroxyethyl) uracil followed by oxidation, dealkylation, and transformation to the resulting sodium polysalt. The final polymer ($\bar M_n \approx 10^4 $) as well as the intermediate products were characterized by 1H-, 13C-, and 31P-NMR spectroscopy. 相似文献
A novel approach for the synthesis of cyclic peptides that can exist in either linear or cyclized conformations is described. Synthesis of the peptides was achieved via a modified solid phase methodology. The reversible linear/cyclized (i.e., open/closed) states are controlled via the reduction/oxidation of a disulfide bond incorporated into the backbone of the peptide chain. 相似文献
26-O-β-D-Glucopyranosyl-furost-5(6),20(22)-dien-3β,26-diol 1, a new furostanol saponin, was isolated from the water-extract of Dioscorea nipponica Mak., the raw material of a traditional Chinese herbal medicine Wei Ao Xin. The structure of 1 was determined on the basis of its spectral data especially by NMR spectroscopy. The result provides the first example of naturally occurring furostanol saponins with a single saccharide chain at the C-26 position. 相似文献
A sensitive and robust high-performance liquid chromatography-electrospray ionization tandem mass spectrometry method to analyze 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and its five metabolites in one passage was developed and validated. The method achieved excellent reproducibility and accuracy. Linearity was observed for all six compounds (R2 = 0.999) with detection limits (S/N ≥ 3) ranging from 0.2 to 2.4 pg on column and 0.01-0.12 ng ml−1 in samples injected. Average intra-day and inter-day variations (% R.S.D.) were 1.2 and 3.5%, respectively. A sample preparation method involving C8 and C18 solid phase extraction provided satisfactory recovery of the analytes in mouse urine. Each NNK metabolite was identified by its chromatographic retention time and specific fragmentation pattern. Since the carcinogenicity of NNK is related to its metabolism, the method described in this report should facilitate toxicological investigations into the carcinogenesis due to NNK exposure in the environment. 相似文献