Observations of stars in the vicinity of the Sun show that binary systems are prevalent and appear to be a general outcome of the star-formation process. One of the major goals of this research is to understand the nature of the formation of binary and multiple stellar systems with typical low-mass stars (∼ 0.2 to 3 M ) and the physical properties of these systems. Basic questions concerning th...

Phytochemical investigation of the aerial parts of Euphorbia erythradenia Bioss. (Euphorbiaceae), one of Iranian endemic Euphorbias, with particular attention to triterpene constituents, using methanol solvent extraction was carried out. Five known triterpenes, including four cycloartanes and oleanolic acid, were isolated for the first time and identified using NMR and Mass techniques. Anti HIV...

Abstract. The fracturing and fragmentation of rock blocks are important phenomena that occur ubiquitously during the propagation avalanches. Here, movement a rectangular block characterized by different joint sets along an upper sloped lower horizontal plane is simulated using discrete element method (DEM) models. pattern set allows to break weak planes at onset fragmentation. With this design,...

Triterpenes, thirty-carbon compounds derived from five-carbon isoprene units, are among the largest and diverse classes of natural products. To date, over 20,000 distinct triterpene structures having more than 100 skeletal variations are indentified from natural sources. The majority of this triterpene diversity is found within the plant kingdom. Plants often accumulate triterpenes in their gly...

Purpose: To optimize extraction of total triterpene acids from loquat leaf and evaluate their in vitro antioxidant activities. Methods: The independent variables were ethanol concentration, extraction time, and solvent ratio, while the dependent variable was content of total triterpene acids. Composite design and response surface method were used to optimize the extraction process, while antiox...

Metabolite identification plays a crucial role in the interpretation of metabolomics research results. Due to its sensitivity and widespread implementation, a favourite analytical method used in metabolomics is electrospray mass spectrometry. In this paper, we demonstrate our results in attempting to incorporate the potentials of multistage mass spectrometry into the metabolite identification r...

MOTIVATION The emerging glycomics and glycoproteomics projects aim to characterize all forms of glycoproteins in different tissues and organisms. Tandem mass spectrometry (MS/MS) is the key experimental methodology for high-throughput glycan identification and characterization. Fragmentation of glycans from high energy collision-induced dissociation generates ions from glycosidic as well as int...

RATIONALE In many legal and regulatory applications, mass spectral comparison of an unknown or questioned sample to a reference standard or database is used for identification; however, no statistical confidence level or error rate is determined. Therefore, a simple and rapid method to establish the statistical equivalence of mass spectra is needed. METHODS The standard deviation of the abund...