Two New Phenolic Glycosides from Viscum articulatum

Two new phenolic glycosides, 1-O-benzyl-[5-O-benzoyl-beta-D-apiofuranosyl (1. 2)]-beta-D-glucopyranoside (1), and 4'-hydroxy-7,3'-dimethoxyflavan-5-O-beta-D-glucopyranoside (2), together with nine known flavanones 3 -11, have been isolated from the dried

Lancifodilactone G: A unique nortriterpenoid isolated from Schisandra lancifolia and its anti-HIV activity

Lancifodilactone G (1), a novel, highly oxygenated nortriterpenoid featuring a partial enol structure and a spirocyclic moiety, was isolated from the medicinal plant Schisandra lancifolia. Its structure and stereochemistry were determined from extensive one- and two-dimensional NMR and mass spectral data, coupled with single-crystal X-ray analysis. Compound 1 exerted minimal cytotoxicity against C8166 cells (CC50 > 200 mu g/mL) and showed anti-HIV activity with EC50 = 95.47 +/- 14.19 mu g/mL and a selectivity index in the range of 1.82-2.46.

Lancifodilactone F: A novel nortriterpenoid possessing a unique skeleton from Schisandra lancifolia and its anti-HIV activity

Lancifodilactone F (1), possessing an unprecedented rearranged pentanortriterpenoid backbone derived from cycloartane, was isolated from the leaves and stems of Schisandra lancifolia (Rehd. et Wils) A. C. Smith. Its structure was established by comprehensive NMR and MS spectroscopic analysis, coupled with single-crystal X-ray experiment. Compound 1 exerted minimal cytotoxicity against C8166 cells (CC50 > 200 mu g/mL) and showed anti-HIV activity with EC50 = 20.69 +/- 3.31 mu g/mL and a selectivity index > 6.62.

The Genomes of Oryza sativa: A history of duplications

We report improved whole-genome shotgun sequences for the genomes of indica and japonica rice, both with multimegabase contiguity, or almost 1,000-fold improvement over the drafts of 2002. Tested against a nonredundant collection of 19,079 full-length cDNAs, 97.7% of the genes are aligned, without fragmentation, to the mapped superscaffolds of one or the other genome. We introduce a gene identification procedure for plants that does not rely on similarity to known genes to remove erroneous predictions resulting from transposable elements. Using the available EST data to adjust for residual errors in the predictions, the estimated gene count is at least 38,000 - 40,000. Only 2% - 3% of the genes are unique to any one subspecies, comparable to the amount of sequence that might still be missing. Despite this lack of variation in gene content, there is enormous variation in the intergenic regions. At least a quarter of the two sequences could not be aligned, and where they could be aligned, single nucleotide polymorphism ( SNP) rates varied from as little as 3.0 SNP/kb in the coding regions to 27.6 SNP/kb in the transposable elements. A more inclusive new approach for analyzing duplication history is introduced here. It reveals an ancient whole-genome duplication, a recent segmental duplication on Chromosomes 11 and 12, and massive ongoing individual gene duplications. We find 18 distinct pairs of duplicated segments that cover 65.7% of the genome; 17 of these pairs date back to a common time before the divergence of the grasses. More important, ongoing individual gene duplications provide a never-ending source of raw material for gene genesis and are major contributors to the differences between members of the grass family.

Dichotomains A and B: Two new highly oxygenated phenolic derivatives from Dicranopteris dichotoma

Dichotomains A (1) and B (2), two new highly oxygenated phenolic derivatives that feature a spirodilactone moiety in their structures, were isolated from the fronds of Dicranopteris dichotoma. Their structures were elucidated on the basis of NMR and MS sp

Nortriterpenoids from Schisandra lancifolia

Six new nortriterpenoids, lancifodilactones 1-N (1-6), as well as nine known ones, were isolated from the leaves and stems of Schisandra lancifolia. Their structures were elucidated on the basis of spectroscopic methods including 2D NMR analysis, and the

Sphenadilactones A and B, two novel nortriterpenoids from Schisandra sphenanthera

Two novel nortriterpenoid compounds, sphenadilactones A (1) and B (2), have been isolated from the leaves and stems of Schisandra sphenanthera. The structural elucidation of 1 and 2 was accomplished by extensive NMR analysis. The relative stereochemistry

Triterpenoids from Schisandra lancifolia with anti-HIV-1 activity

A new trinorcycloartane triterpenoid, lancifodilactone H (1), and a new A ring-secocycloartane triterpenoid, lancifoic acid A (2), together with a known compound, nigranoic acid (3), were isolated from the leaves and stems of Schisandra lancifolia. Their

Rubriflordilactones A and B, two novel bisnortriterpenoids from Schisandra rubriflora and their biological activities

Rubriflordilactones A (1) and B (2), two novel highly unsaturated rearranged bisnortriterpenoids possessing a biosynthetically modified aromatic D-ring, were isolated from the leaves and stems of Schisandra rubriflora. Their structures were established on

Preparation and characterization of three monoclonal antibodies against HIV-1 p24 capsid protein

HIV4 p24 detection provides a means to aid the early diagnosis of HIV-1 infection, track the progression of disease and assess the efficacy of antiretroviral therapy. In the present study, three monoclonal antibodies (mAbs) p3JB9, p5F1 and p6F4 against HI

Isolation and structure elucidation of nortriterpenoids from Schisandra rubriflora

Seven new highly oxygenated nortriterpenoids, rubriflorins D-J (1-7), were isolated from the leaves and stems of Schisandra rubriflora, and their structures were elucidated on the basis of extensive analysis of spectroscopic data. These new compounds feat

Sphenalactones A-D, a new class of highly oxygenated trinortriterpenoids from Schisandra sphenanthera

Four novel highly oxygenated trinortriterpenoids, sphenalactones A-D (1-4), were isolated from the leaves and stems of Schisandra sphenanthera and their structures were elucidated by extensive analysis of 1D and 2D NMR data. Compounds 1-4 featured a C-27

Evolutionary characteristics of exons expressed at different abundance levels in mammals

With comparative genomics approaches, we evaluated the evolutionary characteristics of conservation of exons which are expressed abundantly, moderately or lowly in mammals. Using non-coding regions and pseudogenes as controls, sequence identity, phastCons

Triterpenoids from Schisandra rubriflora

Investigation of an organic extract of Schisandra rubriflora led to the isolation of three new highly oxygenated nortriterpenoids, named rubriflorins A-C (1-3), together with six related known compounds (4-9). Their structures were elucidated by spectrosc

The sequence and de novo assembly of the giant panda genome

Using next-generation sequencing technology alone, we have successfully generated and assembled a draft sequence of the giant panda genome. The assembled contigs (2.25 gigabases (Gb)) cover approximately 94% of the whole genome, and the remaining gaps (0.05 Gb) seem to contain carnivore-specific repeats and tandem repeats. Comparisons with the dog and human showed that the panda genome has a lower divergence rate. The assessment of panda genes potentially underlying some of its unique traits indicated that its bamboo diet might be more dependent on its gut microbiome than its own genetic composition. We also identified more than 2.7 million heterozygous single nucleotide polymorphisms in the diploid genome. Our data and analyses provide a foundation for promoting mammalian genetic research, and demonstrate the feasibility for using next-generation sequencing technologies for accurate, cost-effective and rapid de novo assembly of large eukaryotic genomes.