Dataset: NMR raw dataInstrument: Agilent VNMRS 600 NMR spectrometer

This  paper describes  the isolation and comparative studies on NMR spectra of cardenolide glycosides from Streptocaulon tomentosum Wight & Arnott (Asclepiadaceae).  Nine cardenolides were isolated from the roots of Streptocaulon tomentosum. by column chromatography and identified by NMR spectroscopy. They are 17α-H-periplogenin, 17α-H-periplogenin-β-D digitoxose,17α-H-periplogenin-β-D cymarose, 17α-H-periplogenin-β-glucosyl-(1-4)-2-O-acetyl-digitalose, 17β-H-periplogenin, 17β-H-periplogenin-β-D digitoxose, 17β-H-periplogenin-β-D cymarose, 17α -H-digitoxigenin, and 17 α-H-digitoxigenin-β-D-digitoxoside. Comparative studies on NMR spectra of cardenolide glycosides were carried out. Six cardenolides isolated from Streptocaulon tomentosum were tested for their antiproliferative activity in vitro against MCF-7 (human breast cancer cell line) and L 929 (mouse fibroblast cell line). Among these six cardenolides, 17α-H-periplogenin-3-O-β-D-digitoxoside and 17α-H-periplogenin-3-O-β-D-cymaroside exhibit significant antiproliferative activity (IC50 values, < 1μM) against MCF-7. Four cardenolides  were examined for their cellular viability in the tumor cell and  U 937  (human leukemic cell line) at concentrations 100 μM, 10 μM, and 1 μM. All these four cardenolides  show the induction of apoptosis at 100 μM and 10 μM in both cell lines.

The continued high rates of using antibiotics in healthcare and livestock, without sufficient new compounds reaching the market, has led to a dramatic increase in antimicrobial resistance, with multidrug-resistant bacteria emerging as a major public health threat worldwide. Because the vast majority of antiinfectives are natural products or have originated from them, we assessed the predictive power of plant molecular phylogenies and species distribution modeling in the search for clades and areas which promise to provide a higher probability of delivering new antiinfective compound leads. Our approach enables taxonomically and spatially targeted bioprospecting and supports the battle against the global antimicrobial crisis.

1H-NMR is a very reproducible spectroscopic method and, therefore, a powerful tool for the metabolomic analysis of biological samples. However, due to the high complexity of natural samples, such as plant extracts, the evaluation of spectra is difficult because of signal overlap. The new NMR “Pure Shift” methods improve spectral resolution by suppressing homonuclear coupling and turning multiplets into singlets. The PSYCHE (Pure Shift yielded by Chirp excitation) and the Zangger–Sterk pulse sequence were tested. The parameters of the more suitable PSYCHE experiment were optimized, and the extracts of 21 Hypericum species were measured. Different evaluation criteria were used to compare the suitability of the PSYCHE experiment with conventional 1H-NMR. The relationship between the integral of a signal and the related bin value established by linear regression demonstrates an equal representation of the integrals in binned PSYCHE spectra compared to conventional 1H-NMR. Using multivariate data analysis based on both techniques reveals comparable results. The obtained data demonstrate that Pure Shift spectra can support the evaluation of conventional 1H-NMR experiments.

Preparations of Rhodiola rosea root are widely used in traditional medicine. They can increase life span in worms and flies, and have various effects related to nervous system function in different animal species and humans. However, which of the compounds in R. rosea is mediating any one of these effects has remained unknown in most cases. Here, an analysis of the volatile and non-volatile low-molecular-weight constituents of R. rosea root samples was accompanied by an investigation of their behavioral impact on Drosophila melanogaster larvae. Rhodiola rosea root samples have an attractive smell and taste to the larvae, and exert a rewarding effect. This rewarding effect was also observed for R. rosea root extracts, and did not require activity of dopamine neurons that mediate known rewards such as sugar. Based on the chemical profiles of R. rosea root extracts and resultant fractions, a bioactivity-correlation analysis (AcorA) was performed to identify candidate rewarding compounds. This suggested positive correlations for – among related compounds – ferulic acid eicosyl ester (FAE-20) and β-sitosterol glucoside. A validation using these as pure compounds confirmed that the correlations were causal. Their rewarding effects can be observed even at low micromolar concentrations and thus at remarkably lower doses than for any known taste reward in the larva. We discuss whether similar rewarding effects, should they be observed in humans, would indicate a habit-forming or addictive potential.

Phytochemical investigation of the roots of O. sennoides subsp. zanzibaricum Brenan & J.B. Gillett resulted in the isolation of three biflavonoids (trime-chamaejasmin, (+)- chamaejasmin, (+)-liquiritigeninyl-(I-3,II-3)-naringenin), one bi-4-phenyldihydrocoumarin (diphysin), one isoflavan (glabridin), one triterpenoid (3-O-acetyloleanoic acid) and a phytosterol (β-sitosterol). Compounds were identified by detailed MS, 1D and 2D NMR spectroscopic analyses. Their absolute configurations were elucidated based on ECD spectra. The previously undescribed trime-chamaejasmin represents a bis-epi-chamaejasmenin C diastereomer. The chemophenetic significance is discussed in detail. The results contribute to the phytochemical characterization of the genus Ormocarpum and suggest a close chemophenetic relationship with other genera within the subfamily Papilionoideae. Furthermore, this report provides baseline data for comparing the two infraspecific taxa of O. sennoides (Willd.) DC.

Phyllanthus orbicularis (Phyllanthaceae) is an endemic evergreen tropical plant of Cuba that grows in the western part of the island and is used in traditional medicine as an infusion. The aqueous extract of this plant presents a wide range of pharmacological activitiessuch as antimutagenic, antioxidant and antiviral effects. Given the many beneficial effects and the great interest in the development of new pharmacological products from natural sources, the aim of this work was to investigate the phytochemistry of this species and to elucidate the structure of the main bioactive principles. Besides thepresence of several known polyphenols, the major constituent was hitherto not described. The chemical structure of this compound, here named Fideloside, was elucidated by means of HR-ESIMS/MSn, 1D/2D NMR, FT-IR, and ECD as (2R,3R)-(−)-3’,4 ,5,7-tetrahydroxydihydroflavonol-8-C- -D-glucopyranoside. The compound, as well as the plant aqueous preparations, showed promising bioactive properties, i.e., anti-inflammatory capacity in human explanted monocytes, corroborating future pharmacological use for this new natural C-glycosyl flavanonol.