STEREOSTRUCTURAL DETERMINATION OF ADDITION PRODUCTS FROM ISOFURANOGERMACRENE AND MALEIMIDE BY NMR TECHNIQUES

The stereostructures of the title compounds were shown to be represented by (A) and (B).

Separation, Identification, Isolation and Characterization of Degradation Product of Osimertinib Tablets by UPLC-QTOF-MS/MS and NMR: Evaluation of <i>In-Silico</i>Safety Assessment for Osimertinib (OSM) and Degradation Product (DP)

The present work encompasses identification and characterization of major degradation product (DP) of OSM observed in base hydrolytic stress study. The separation of DP was carried out on a non-polar stationary phase by using high-performance liquid chromatography system (HPLC). Using waters X-bridge (250 mm × 4.6 mm, 5 μm) C18 column with gradient elution program. For the characterization study, stress samples were subjected to HPLC and UPLC-QTOF-MS/MS and based on mass fragmentation pattern, plausible structure was deduced. Further, the DP was isolated using semi-prepara- tive liquid chromatography and concentrated the fractions using lyophilization. The isolated DP was subjected to extensive 1D (1H, 13C, and DEPT-135) and 2D (COSY, HSQC and HMBC) nuclear magnetic resonance (NMR) studies to authenticate the structure. The impurity was unambiguously named as N-(2-((2-(dimethylamino)ethyl)(methyl)amino)-4-metho-xy-5-((4-(1-methyl-1H-indol-3-yl)pyrimidin-2-yl)amino)phenyl)-3-methoxypropanamide. Add- itionally, the In-Silico structure activity relation (QSAR) assessed through statistical based software’s DEREK NexusTM, and MultiCASE, Case UltraTM widely accepted and respected software’s for DP and OSM.

Monepaloside K, a New Triterpenoid Saponin from Morina nepalensis var. alba Hand. - Mazz.

One new triterpenoid saponin, monepaloside K (1) was isolated from the water-soluble part of the whole plant of a famous Tibetan medicinal herb, morina nepalensis var. alba Hand.-Mazz.. Its structure was determined to be 3-O-a-L-arabinopyranosyl-(13)-b-D- xylopyranosyl siaresinolic acid on the basis of spectroscopic evidences, especially 2D NMR techniques.

Nuclear Magnetic Resonance technique in tumor metabolism

Cancer is one of the most serious diseases that cause an enormous number of deaths all over the world.Tumor metabolism has great discrimination from that of normal tissues.Exploring the tumor metabolism may be one of the best ways to find biomarkers for cancer detection,diagnosis and to provide novel insights into internal physiological state where subtle changes may happen in metabolite concentrations.Nuclear Magnetic Resonance(NMR)technique nowadays is a popular tool to analyze cell extracts,tissues and biological fluids,etc,since it is a relatively fast and an accurate technique to supply abundant biochemical information at molecular levels for tumor research.In this review,approaches in tumor metabolism are discussed,including sample collection,data profiling and multivariate data analysis methods etc.Some typical applications of NMR are also summarized in tumor metabolism.

Two new phenylpropanoid glycosides from Sanguisorba officinalis

Two new phenylpropanoid glycosides, 9-O-[6-O-acetyl-β-D-glucopyranosyl]-4-hydroxycinnamic acid （1） and 8-O-β-D-glucopyranosyl-（R）-（＋）-3,4,8-trihydroxy methyl phenylpropionate （2） were isolated from the 80% EtOH extract of the roots of Sanguisorba officinalis. Their slructures were characterized by spectroscopic analysis and chemical method, including 1D NMR, 2D NMR, and HR-ESI-MS. Compounds 1 and 2 exhibited the moderate antimicrobial activities against all Gram-positive and Gram-negative bacteria tested.

Two new compounds from Coriaria nepalensis

Two new compounds. corialins A （1） and B （2） were isolated from Coriaria nepulensis Wall. These new compounds were established as 7-hydroxy-3-[2,3-acetonidc-（3-methylhutane）] coumarin （1） and 3-O-β-D-glucopyranosyl-3,4,5-1rihydroxy-1-（3- methyl-2-butenyl）-benzene （2）. on the basis of ID and 2D NMR techniques.