Four new degradation products of doxorubicin:An application of forced degradation study and hyphenated chromatographic techniques

Forced degradation study on doxorubicin （DOX） was carried out under hydrolytic condition in acidic, alkaline and neutral media at varied temperatures, as well as under peroxide, thermal and photolytic conditions in accordance with International Conference on Harmonization （ICH） guidelines Q1（R2）. It was found extremely unstable to alkaline hydrolysis even at room temperature, unstable to acid hy- drolysis at 80 ℃, and to oxidation at room temperature. It degraded to four products （O-I-O-IV） in oxidative condition, and to single product （A-l） in acid hydrolytic condition. These products were re- solved on a C8 （150 mm × 4.6 mm, 5μm） column with isocratic elution using mobile phase consisting of HCOONH4 （10 mM, pH 2.5）, acetonitrile and methanol （65：15：20, v/v/v）. Liquid chromatography-pho- todiode array （LC-PDA） technique was used to ascertain the purity of the products noted in LC-UV chromatogram. For their characterization, a six stage mass fragmentation （MS6） pattern of DOX was outlined through mass spectral studies in positive mode of electrospray ionization （＋ESI） as well as through accurate mass spectral data of DOX and the products generated through liquid chromato- graphy-time of flight mass spectrometry （LC-MS-TOF） on degraded drug solutions. Based on it, O-I-O-IV were characterized as 3-hydroxy-9-desacetyldoxorubicin-9-hydroperoxide, l-hydroxy-9-desacetyldox- orubicin-9-hydroperoxide, 9-desacetyldoxorubicin-9-hydroperoxide and 9-desacetyldoxorubicin, re- spectively, whereas A-I was characterized as deglucosaminyl doxorubicin. While A-I was found to be a pharmacopoeial impurity, all oxidative products were found to be new degradation impurities. The mechanisms and pathways of degradation of doxorubicin were outlined and discussed.

Fragrep: An Efficient Search Tool for Fragmented Patterns in Genomic Sequences

Many classes of non-coding RNAs （ncRNAs; including Y RNAs, vault RNAs, RNase P RNAs, and MRP RNAs, as well as a novel class recently discovered in Dictyostelium discoideum） can be characterized by a pattern of short but well-conserved sequence elements that are separated by poorly conserved regions of sometimes highly variable lengths. Local alignment algorithms such as BLAST are therefore ill-suited for the discovery of new homologs of such ncRNAs in genomic sequences. The Fragrep tool instead implements an efficient algorithm for detecting the pattern fragments that occur in a given order. For each pattern fragment, the mismatch tolerance and bounds on the length of the intervening sequences can be specified separately. Furthermore, matches can be ranked by a statistically well-motivated scoring scheme.

Glycerolipid Profiling of Yellow Sarson Seeds Using Ultra High Performance Liquid Chromatography Coupled to Triple Time-of-Flight Mass Spectrometry

Yellow sarson(Brassica rapa ssp. trillocularis) is an important rapeseed-mustard species of Brassica rapa due to its high seed oil content. Glycerolipids and fatty acid composition affect seed germination and determine the quality of seed oil. To date, no information is available on the composition of individual glycerolipids in this species. Therefore, in this study the glycerolipid profiling of yellow sarson seeds was performed using ultra high performance liquid chromatography coupled to triple time-of-flight mass spectrometry(UPLC-Triple-TOF-MS).A fast and efficient chromatographic separation of glycerolipids was accomplished based on an UPLCTMBEH C8 column within 22 min.In ESI positive ion mode, TOF-MS scan-information dependent acquisition-product ion scan was carried out to acquire both high resolution MS and MS/MS information from one injection. According to MS/MS spectra, predominant fragmentation patterns of glycerolipids were elucidated in detail. Based on retention time, accurate mass, isotopic distribution, and fragmentation patterns, the composition of 144 glycerolipids and fatty acids were finally identified in yellow sarson seeds, including 77 triacylglycerols, 32 diacylglycerols, 18sulfoquinovosyl-diacylglycerols, 5 monogalactosyl-diaclyglycerols, and 12 digalactosyl-diacylglycerols. Of them, the most abundant glycerolipids in yellow sarson seeds were triacylglycerols, the major storage form of seed oil in plants. In addition, diacylglycerols were found as a minor component of glycerolipids. The lowest amounts of glycerolipids detected in seeds were glycosyl-acylglycerols. The results revealed the composition and relative content of glycerolipids in yellow sarson seeds, which will provide a more comprehensive assessment of the quality of seed oil and also help to select functional cultivars with higher beneficial glycerolipids. This profiling method has the advantages of high throughput, high sensitivity and good accuracy, which will provide a reliable analysis platform for glycerolipids metabolism in plants.

Assessment of multifunctional landscapes dynamics in the mountainous basin of the Mo River （Togo, West Africa）

In this study, historical landscape dynamics were investigated to（i） map the land use/cover types for the years 1972, 1987, 2000 and 2014;（ii） determine the types and processes of landscape dynamics; and（iii） assess the landscape fragmentation and habitat loss over time. Supervised classification of multi-temporal Landsat images was used through a pixel-based approach. Post–classification methods included systematic and random change detection, trajectories analysis and landscape fragmentation assessment. The overall accuracies（and Kappa statistics） were of 68.86%（0.63）, 91.32%（0.79）, 90.66%（0.88） and 91.88%（0.89） for 1972, 1987, 2000 and 2014, respectively. The spatio-temporal analyses indicated that forests, woodlands and savannahs dominated the landscapes during the four dates, though constant areal decreases were observed. The most important dynamic process was the decline of woodlands with an average annual net loss rate of –2%. Meanwhile, the most important land transformation occurred during the transition 2000–2014, due to anthropogenic pressures. Though the most important loss of vegetation greenness occurred in the unprotected areas, the overall analyses of change indicated a declining trend of land cover quality and an increasing landscape fragmentation. Sustainable conservation strategies should be promoted while focusing restoration attention on degraded lands and fragmented ecosystems in order to support rural livelihood and biodiversity conservation.