Map indicating the distribution of <i>Fritillaria</i> in China.

<p>The distribution area of each species is drawn according to the records in the FOC and Flora Xinjiangensis. Photographs of the species are also provided.</p

Comparison of 13 <i>Fritillaria</i> cp genomes with <i>F</i>. <i>cirrhosa</i> as the reference.

<p>LSC: long single copy region; SSC: short single copy region; IRa and IRb: inverted regions. Gray arrow: gene and translation direction; blue block: exon of the gene; red block: conserved non-coding sequences (CNS). Sequence identities are labeled at the right side and range between 50%-100%.</p

The evolutionary progression of stigmatic traits within the genus.

<p>The evolutionary progression of stigmatic traits within the genus.</p

Gene map of the <i>Fritillaria</i> cp genome.

<p>Genes belonging to different functional groups are color-coded. The dashed area in the inner circle indicates the GC content. Cp genome size ranges are provided for the seven Xinjiang <i>Fritillaria</i> species.</p

Comparison of LSC, SSC, and IR border regions among the 13 <i>Fritillaria</i> cp genomes.

<p>Colored boxes for genes represent the gene position. ψ: pseudogenes. *: these six species were redrawn according to Park et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194613#pone.0194613.ref021" target="_blank">21</a>].</p

Variable site analyses in <i>Fritillaria</i> chloroplast genomes.

<p>Variable site analyses in <i>Fritillaria</i> chloroplast genomes.</p

Complete chloroplast genome of seven <i>Fritillaria</i> species, variable DNA markers identification and phylogenetic relationships within the genus

<div><p><i>Fritillaria</i> spp. constitute important traditional Chinese medicinal plants. Xinjiang is one of two diversity hotspots in China in which eight <i>Fritillaria</i> species occur, two of which are endemic to the region. Furthermore, the phylogenetic relationships of Xinjiang <i>Fritillaria</i> species (including <i>F</i>. <i>yuminensis</i>) within the genus are unclear. In the present study, we sequenced the chloroplast (cp) genomes of seven <i>Fritillaria</i> species in Xinjiang using the Illumina HiSeq platform, with the aim of assessing the global structural patterns of the seven cp genomes and identifying highly variable cp DNA sequences. These were compared to previously sequenced <i>Fritillaria</i> cp genomes. Phylogenetic analysis was then used to evaluate the relationships of the Xinjiang species and assess the evolution of an undivided stigma. The seven cp genomes ranged from 151,764 to 152,112 bp, presenting a traditional quadripartite structure. The gene order and gene content of the seven cp genomes were identical. A comparison of the 13 cp genomes indicated that the structure is highly conserved. Ten highly divergent regions were identified that could be valuable in phylogenetic and population genetic studies. The phylogenetic relationships of the 13 <i>Fritillaria</i> species inferred from the protein-coding genes, large single-copy, small single-copy, and inverted repeat regions were identical and highly resolved. The phylogenetic relationships of the species corresponded with their geographic distribution patterns, in that the north group (consisting of eight species from Xinjiang and Heilongjiang in North China) and the south group (including six species from South China) were basically divided at 40°N. Species with an undivided stigma were not monophyletic, suggesting that this trait might have evolved several times in the genus.</p></div

Pharmacokinetics of 5-FA and 5-FA-PAE after <i>i.v.</i> injection.

<p>The control group and the test groups were administered intravenously with 20 mg/kg of 5-FA or 189 mg/kg of 5-FA-PAE (equivalent to 20 mg/kg of 5-FA) dissolved in physiological saline, respectively. Each plasma sample of the 5-FA-PAE group was divided into two portions (treated as hydrolyzed and unhydrolyzed), which were analyzed by HPLC to determine the plasma concentrations of released 5-FA and total 5-FA of the conjugate whereas the plasma samples of the control group were treated as unhydrolyzed samples. Each value represents the mean ± standard deviation (n = 6).</p

The antitumor effects on tumor-bearing mice.

<p>Mice were i.v injected with saline (20 mg/kg, 0.160 mmol/kg), 5-FA-PAE (284 mg/kg, 0.160 mmol/kg), 5-FA (30 mg/kg, 0.160 mmol/kg) or 5-Fu (20.47 mg/kg, 0.160 mmol/kg) on day 3, 5, 7, 9, 11, 13 and 15 after inoculation of H22 cells. On day 20, mice were sacrificed. Tumors and organs were removed and weighed. (A) The tumor volumes after inoculation (n = 6–12). * <i>p</i><0.05, ** <i>p</i><0.01. (B) Images of tumors in tumor-bearing mice on day 20 after inoculation of tumor cells (n = 6).</p

A Polymeric Prodrug of 5-Fluorouracil-1-Acetic Acid Using a Multi-Hydroxyl Polyethylene Glycol Derivative as the Drug Carrier

<div><p>Purpose</p><p>Macromolecular prodrugs obtained by covalently conjugating small molecular drugs with polymeric carriers were proven to accomplish controlled and sustained release of the therapeutic agents <i>in vitro</i> and <i>in vivo</i>. Polyethylene glycol (PEG) has been extensively used due to its low toxicity, low immunogenicity and high biocompatibility. However, for linear PEG macromolecules, the number of available hydroxyl groups for drug coupling does not change with the length of polymeric chain, which limits the application of PEG for drug conjugation purposes. To increase the drug loading and prolong the retention time of 5-fluorouracil (5-Fu), a macromolecular prodrug of 5-Fu, 5-fluorouracil-1 acid-PAE derivative (5-FA-PAE) was synthesized and tested for the antitumor activity <i>in vivo</i>.</p><p>Methods</p><p>PEG with a molecular weight of 38 kDa was selected to synthesize the <i>multi-hydroxyl polyethylene glycol</i> derivative (PAE) through an addition reaction. 5-fluorouracil-1 acetic acid (5-FA), a 5-Fu derivative was coupled with PEG derivatives via ester bond to form a macromolecular prodrug, 5-FA-PAE. The <i>in vitro</i> drug release, pharmacokinetics, <i>in vivo</i> distribution and antitumor effect of the prodrug were investigated, respectively.</p><p>Results</p><p>The PEG-based prodrug obtained in this study possessed an exceedingly high 5-FA loading efficiency of 10.58%, much higher than the maximum drug loading efficiency of unmodified PEG with the same molecular weight, which was 0.98% theoretically. Furthermore, 5-FA-PAE exhibited suitable sustained release in tumors.</p><p>Conclusion</p><p>This study provides a new approach for the development of the delivery to tumors of anticancer agents with PEG derivatives.</p></div