An unusual dimeric guaianolide, artemilinin A (1) and a sesquiterpene-monoterpene lactone, isoartemisolide (2), were isolated from the leaves of Artemisia argyi. Their structures were elucidated on the basis of extensive spectroscopic analysis (IR, HR-ESIMS, 1D- and 2D-NMR), and the absolute configurations were determined by CD spectra and quantum chemical ECD calculation. Furthermore, in in vi...

Six sesquiterpenoids 1-6, including two new ones, an ent-daucane-type sesquiterpenoid, asperaculane A (1), and a nordaucane one, asperaculane B (2), and four known nordaucane derivatives, aculenes A-D 3-6, together with the known secalonic acid D (7), were isolated from a fermentation culture of the fungus Aspergillus aculeatus. Their structures and absolute configurations were established by a...

Duas novas e duas conhecidas saponinas triterpênicas foram isoladas da casca do caule de Pentaclethra macroloba. As estruturas foram determinadas usando uma combinação de técnicas de RMN homo(1D: RMNH, RMNC-{H}, RMNC-DEPT135; 2D: H-H-COSY, H-HTOCSY, H-H-NOESY) and heteronuclear 2D (HMQC and HMBC), espectros de massas obtidos com ionização por pulverização eletrônica (ESIMS) e métodos químicos. ...

Liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESIMS/MS) is one of the most prominent analytical techniques owing to its inherent selectivity and sensitivity. In LC/ESI-MS/MS, chemical derivatization is frequently used to enhance the MS/MS detectability. The derivatization improves the separation and ionization efficiency. Moreover, the generated derivatives give par...

Here we report the solid phase synthesis and characterization (LC-ESIMS, CD) of a cationic nucleobase-containing α-peptide, composed of both l-arginine residues and l-lysine-based nucleoamino acids sequentially present in the structure. The binding properties of this novel basic nucleopeptide towards nucleic acids were investigated by CD spectroscopy which revealed the ability of the thymine-co...

The degradation of caffeic acid under ultrasound treatment in a model system was investigated. The type of solvent and temperature were important factors in determining the outcome of the degradation reactions. Liquid height, ultrasonic intensity and duty cycle only affected degradation rate, but did not change the nature of the degradation. The degradation rate of caffeic acid decreased with i...

Here we describe the design of 1,2-phenylenediamine capturing molecule and the synthesis steps necessary for its preparation. The designed 1,2-phenylenediamine derivative is able to capture diacetyl in solution, as shown by ESIMS, forming a chemical adduct, 1-4-quinoxaline. The methyl esters of diacetyl-adduct (DAA) and pentanedione-adduct (PDA) are incorporated to the lysines in BSA and the co...

Abstract A strategy for the generation of heterotrimetallic double cavity (DC) cages [Pd n Pt m L 4 ] 6+ ( DC1 : =1, =2; and DC2 =2, =1) is reported. The DC were generated by combining an inert platinum(II) tetrapyridylaldehyde complex with a suitably substituted pyridylamine Pd II ions. 1 H DOSY nuclear magnetic resonance spectroscopy (NMR) electrospray ionization mass spectrometry (ESIMS) dat...

One new cycloartane-type saponin, 3-O-[β-D-xylopyranosyl-(1→2)-β-D-xylopyranosyl]-6-O-β-Dglucuronopyranosyl-3β,6α,16β,24(S),25-pentahydroxyxyxloartane (1) was isolated from the MeOH extract of whole plant parts of Astragalus erinaceus along with 5 known saponins (2-6), cyclodissectoside, cycloastragenol, 6-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane, oleifolioside B and 3,6d...

Stachys brachyclada de Noé ex Coss. (Lamiaceae) is a quite rare medicinal plant endemic to the Mediterranean basin. In this study, seven secondary metabolites from methanol extract of its leaves have been isolated and identified by combination chromatographic spectroscopic methods (1D 2D NMR experiments ESIMS analysis). They include one ethyl 4-hydroxybenzoate (1), three acylated flavone glycos...