A New Lignan and C(6)-Oxygenated Flavonoids from the Inflorescence of Ambrosia artemisiifolia.

A new lignan (4,4',5'-trihydroxy-5,3'-dimethoxy-3-O-9',2-(7'R)-lignan, 1) and eight C(6)-oxygenated flavonoids (2-9), including a newly identified flavonoid (7,3',4'-trihydroxy-3,5,6-trimethoxyflavone, 2), were isolated from the inflorescence of Ambrosia artemisiifolia L. The structures of these isolates were determined using extensive spectroscopic analyses and comparison with data previously reported in the literature. The absolute configuration of compound 1 was established using electronic circular dichroism (ECD) spectrum. All the flavonoids (2-9) showed inhibitory effects on LPS-induced NO production in RAW264.7 cells, with the inhibition rate ranging from 24.51 % to 69.82 % at 50 µM. The in vitro cytotoxicity study showed that compounds 3-8 have a 60 % inhibition rate against SMMC-7721 at a concentration of 40 µM, while compounds 5 and 8 also exhibited inhibitory activity against HL-60 at 40 µM with the inhibition rate of 83.36 % and 52.01 %, respectively.

New Cyclic Diarylheptanoids from Platycarya strobilacea.

Five new cyclic diarylheptanoids (platycary A-E, compounds 1-5) and three previously identified analogues (i.e., phttyearynol (compound 6), myricatomentogenin (compound 7), and juglanin D (compound 8)) were isolated from the stem bark of Platycarya strobilacea. The structures of these compounds were determined using NMR, HRESIMS, and electronic circular dichroism (ECD) data. The cytotoxicity of compounds 1-5 and their ability to inhibit nitric oxide (NO) production, as well as protect against the corticosterone-induced apoptosis of Pheochromocytoma (PC12) cells, were evaluated in vitro using the appropriate bioassays. Compounds 1 and 2 significantly inhibited the corticosterone-induced apoptosis of PC12 cells at a concentration of 20 µΜ.

A new epicatechin glucopyranoside derivative from Styrax suberifolius.

A new derivative of epicatechin glucopyranoside, (2R,3R)-3,7,4'-trihydroxy-5,3'-dimethoxyflavan 7-O-ß-d-glucopyranoside (1), together with three mononuclear phenolic acid esters, methyl orsellinate (2), ethyl orsellinate (3) and methyl ß-orcinolcarboxylate (4) were isolated from the bark of Styrax suberifolius. The structures of 1-4 were determined on the basis of extensive analysis of NMR and MS spectra combined with chemical hydrolysis. The antifungal activities of the isolated compounds against three plant pathogenic fungi, Alternaria solani, Fusarium oxysporum and Phomopsis cytospore were evaluated using radial growth inhibition assay. Compounds 2, 3 and 4 exerted selective inhibitory activities against the tested fungi. Among of them, methyl ß-orcinolcarboxylate (4) exhibited obvious inhibitory effect against P. cytospore, with an inhibition rate of 86.72% at 100 µg/ml.

Phylogenetic Diversity and Antifungal Activity of Endophytic Fungi Associated with Tephrosia purpurea.

Sixty-one endophytic fungus strains with different colony morphologies were isolated from the leaves, stems and roots of Tephrosia purpurea with colonization rates of 66.95%, 37.50%, and 26.92%, respectively. Based on internal transcribed spacer sequence analysis, 61 isolates were classified into 16 genera belonging to 3 classes under the phylum Ascomycota. Of the 61 isolates, 6 (9.84%) exhibited antifungal activity against one or more indicator plant pathogenic fungi according to the dual culture test. Isolate TPL25 had the broadest antifungal spectrum of activity, and isolate TPL35 was active against 5 plant pathogenic fungi. Furthermore, culture filtrates of TPL25 and TPL35 exhibited greater than 80% growth inhibition against Sclerotinia sclerotiorum. We conclude that the endophytic fungal strains TPL25 and TPL35 are promising sources of bioactive compounds.

Sequence analysis of mitochondrial ND1 gene can reveal the genetic structure and origin of Bactrocera dorsalis s.s.

BACKGROUND: The oriental fruit fly, Bactrocera dorsalis s.s., is one of the most important quarantine pests in many countries, including China. Although the oriental fruit fly has been investigated extensively, its origins and genetic structure remain disputed. In this study, the NADH dehydrogenase subunit 1 (ND1) gene was used as a genetic marker to examine the genetic diversity, population structure, and gene flow of B. dorsalis s.s. throughout its range in China and southeast Asia. RESULTS: Haplotype networks and phylogenetic analysis indicated two distinguishable lineages of the fly population but provided no strong support for geographical subdivision in B. philippinensis. Demographic analysis revealed rapid expansion of B. dorsalis s.s. populations in China and Southeast Asia in the recent years. The greatest amount of genetic diversity was observed in Manila, Pattaya, and Bangkok, and asymmetric migration patterns were observed in different parts of China. The data collected here further show that B. dorsalis s.s. in Yunnan, Guangdong, and Fujian Provinces, and in Taiwan might have different origins within southeast Asia. CONCLUSIONS: Using the mitochondrial ND1 gene, the results of the present study showed B. dorsalis s.s. from different parts of China to have different genetic structures and origins. B. dorsalis s.s. in China and southeast Asia was found to have experienced rapid expansion in recent years. Data further support the existence of two distinguishable lineages of B. dorsalis s.s. in China and indicate genetic diversity and gene flow from multiple origins.The sequences in this paper have been deposited in GenBank/NCBI under accession numbers KC413034-KC413367.

Genome-wide analyses of two families of snoRNA genes from Drosophila melanogaster, demonstrating the extensive utilization of introns for coding of snoRNAs.

Small nucleolar RNAs (snoRNAs) are an abundant group of noncoding RNAs mainly involved in the post-transcriptional modifications of rRNAs in eukaryotes. In this study, a large-scale genome-wide analysis of the two major families of snoRNA genes in the fruit fly Drosophila melanogaster has been performed using experimental and computational RNomics methods. Two hundred and twelve gene variants, encoding 56 box H/ACA and 63 box C/D snoRNAs, were identified, of which 57 novel snoRNAs have been reported for the first time. These snoRNAs were predicted to guide a total of 147 methylations and pseudouridylations on rRNAs and snRNAs, showing a more comprehensive pattern of rRNA modification in the fruit fly. With the exception of nine, all the snoRNAs identified to date in D. melanogaster are intron encoded. Remarkably, the genomic organization of the snoRNAs is characteristic of 8 dUhg genes and 17 intronic gene clusters, demonstrating that distinct organizations dominate the expression of the two families of snoRNAs in the fruit fly. Of the 267 introns in the host genes, more than half have been identified as host introns for coding of snoRNAs. In contrast to mammals, the variation in size of the host introns is mainly due to differences in the number of snoRNAs they contain. These results demonstrate the extensive utilization of introns for coding of snoRNAs in the host genes and shed light on further research of other noncoding RNA genes in the large introns of the Drosophila genome.