Target Spot on Menispermum dauricum Caused by Streptobotrys (≡Streptotinia) caulophylli, a New Disease in China.

Menispermum dauricum (moonseed) (family Menispermaceae), a perennial twining vine, is an ornamental plant traditionally used in Chinese medicine. M. dauricum is distributed mostly in northeastern, northern, and eastern China, Japan, Korea, and southern Siberia (4). Rhizoma menispermi is the dry root of M. dauricum, which has detoxifying and dehumidifying effects, and is mainly used for the treatment of sore throat, enteritis, diarrhea, and rheumatism. From June to September in 2012 and 2013, target spots were observed on moonseed plants, with an incidence above 30% in the medicinal herb garden of the Institute of Special Animal and Plant Sciences at the Chinese Academy of Agricultural Science (44°02' N, 126°05' E) in Jilin Province. Lesions on the leaves were roughly circular, forming concentric rings of alternating light and dark brown bands with yellow halos at the margins, and up to 50 mm in diameter. Lesions coalesced to a large area capable of destroying the leaf. Under humid conditions, the lesions enlarged rapidly. Occasionally, grayish-white mycelia appeared on the lesions. Subsequently, grayish-brown conidiophores arose, singly or in dense groups, up to 700 µm high, with large loose conidial heads. Side branches and branchlets were tightly twisted, brown and 7 to 11 µm in width. Conidiogenous cells were inflated at the apex of the branches and delimited by a septum. Conidia were globose to subglobose, pale brown, unicellular, minutely echinulate, and rounding to 7.8 to 16.9 µm in diameter. Four isolates were obtained from necrotic tissue from leaf spots and cultured on potato dextrose agar (PDA) at 25°C. Mycelia grown on PDA were sparse, whitish-gray, and produced small black sclerotia within 3 to 5 days. Sclerotia were round or oval to oblong and 0.3 to 1.7 × 0.8 to 1.7 mm. No conidiophores or conidia were produced on PDA. The similar species Streptobotrys streptothrix had smooth conidia and small sclerotia. So, all isolates were identified as S. caulophylli based on their morphological and cultural characteristics (2,3). The internal transcribed spacer (ITS) region was amplified by using the primers ITS4 and ITS5 (1). The ITS sequences (529 bp) were identical in these four isolates (Accession No. HG918042). Pathogenicity tests were performed on healthy 2-year-old moonseed plants. Ten leaves were inoculated with a 0.6-cm diameter mycelial plug from 3-day-old PDA cultures for each isolate, and the inoculation sites covered with moistened sterile absorbent cotton. Another 10 leaves were inoculated with sterile PDA plugs as controls. All plants in the experiments were covered with plastic bags and maintained in a greenhouse at 20 to 25°C for 24 h. After 3 days, dark brown spots were observed on all leaves inoculated with these isolates. After 7 days, the classical symptoms were evident, while control plants remained healthy. The re-isolated pathogen was identified as S. caulophylli based on morphological analysis. The pathogenicity test was repeated with similar results. Currently, the economic importance of this disease is limited, but it may become a more significant problem with the cultivation area of M. dauricum increasing. To our knowledge, this is the first report of S. caulophylli causing target spot on M. dauricum in China. References: (1) D. E. L. Cooke et al. Mycol. Res. 101:667, 1997. (2) M. E. Elliott, Can. J. Bot. 40:1197, 1962. (3) S. K. Hong et al. Plant Pathol. J. 20:192, 2004. (4) Y. H. Liu. Page 39 in: Flora Republicae Popularis Sinicae, vol. 30. Sciences Press, Beijing, 1996.

Probing the interaction of trans-resveratrol with bovine serum albumin: a fluorescence quenching study with Tachiya model.

The interaction of trans-resveratrol (TRES) and bovine serum albumin (BSA) was investigated using fluorescence spectroscopy (FS) with Tachiya model. The binding number maximum of TRES was determined to be 8.86 at 293.15 K, 23.42 at 303.15 K and 33.94 at 313.15 K and the binding mechanism analyzed in detail. The apparent binding constants (K (a)) between TRES and BSA were 5.02 x 10(4) (293.15 K), 8.89 x 10(4) (303.15 K) and 1.60 x 10(5) L mol(-1) (313.15 K), and the binding distances (r) between TRES and BSA were 2.44, 3.01, and 3.38 nm at 293.15, 303.15, and 313.15 K, respectively. The addition of TRES to BSA solution leads to the enhancement in RLS intensity, exhibiting the formation of the aggregate in solution. The negative entropy change and enthalpy change indicated that the interaction of TRES and BSA was driven mainly by van der Waals interactions and hydrogen bonds. The process of binding was a spontaneous process in which Gibbs free energy change was negative.

Cytotoxicity of Marchantia convoluta leaf extracts to human liver and lung cancer cells.

The cytotoxicity of three extracts (petroleum ether, ethyl acetate and n-butanol) from a plant used in folk medicine, Marchantia convoluta, to human non-small cell lung carcinoma (H1299) and liver carcinoma (HepG2) cell lines was tested. After 72-h incubation of lung and liver cancer cell cultures with varying concentrations of extracts (15 to 200 microg/mL), cytotoxicity was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and reported in terms of cell viability. The extracts that showed a significant cytotoxicity were subjected to gas chromatography-mass spectrometry analysis to identify the components. The ethyl acetate, but not the petroleum ether or n-butanol extract, had a significant cytotoxicity against lung and liver carcinoma cells with IC50 values of 100 and 30 microg/mL, respectively. A high concentration of ethyl acetate extract (100 microg/mL) rapidly reduced the number of H1299 cells. At lower concentrations of ethyl acetate extract (15, 30, and 40 microg/mL), the numbers of HepG2 cells started to decrease markedly. Gas chromatography-mass spectrometry analysis of the ethyl acetate extract revealed the presence of several compounds such as phytol (23.42%), 1,2,4-tripropylbenzene (13.09%), 9-cedranone (12.75%), ledene oxide (7.22%), caryophyllene (1.82%), and caryophyllene oxide (1.15%). HPLC analysis result showed that there were no flavonoids in ethyl acetate extract, but flavonoids are abundant in n-butanol extract. Further studies are needed regarding the identification, toxicity, and mechanism of action of active compounds.

Cytotoxicity of Marchantia convoluta leaf extracts to human liver and lung cancer cells

The cytotoxicity of three extracts (petroleum ether, ethyl acetate and n-butanol) from a plant used in folk medicine, Marchantia convoluta, to human non-small cell lung carcinoma (H1299) and liver carcinoma (HepG2) cell lines was tested. After 72-h incubation of lung and liver cancer cell cultures with varying concentrations of extracts (15 to 200 æg/mL), cytotoxicity was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and reported in terms of cell viability. The extracts that showed a significant cytotoxicity were subjected to gas chromatography-mass spectrometry analysis to identify the components. The ethyl acetate, but not the petroleum ether or n-butanol extract, had a significant cytotoxicity against lung and liver carcinoma cells with IC50 values of 100 and 30 æg/mL, respectively. A high concentration of ethyl acetate extract (100 æg/mL) rapidly reduced the number of H1299 cells. At lower concentrations of ethyl acetate extract (15, 30, and 40 æg/mL), the numbers of HepG2 cells started to decrease markedly. Gas chromatography-mass spectrometry analysis of the ethyl acetate extract revealed the presence of several compounds such as phytol (23.42 percent), 1,2,4-tripropylbenzene (13.09 percent), 9-cedranone (12.75 percent), ledene oxide (7.22 percent), caryophyllene (1.82 percent), and caryophyllene oxide (1.15 percent). HPLC analysis result showed that there were no flavonoids in ethyl acetate extract, but flavonoids are abundant in n-butanol extract. Further studies are needed regarding the identification, toxicity, and mechanism of action of active compounds.

Calcium absorption from calcium carbonate and a new form of calcium (CCM) in healthy male and female adolescents.

Calcium absorption from two Ca salts was investigated in a crossover design using stable isotopic tracers in 12 healthy adolescents (6 males, 6 females). A Ca supplement in the form of Ca carbonate or Ca citric and malic acids (CCM) was ingested with a standardized breakfast and the order of administration was randomized. The oral supplement contained 250 mg elemental Ca, 21.8 mg of which was highly enriched 44Ca tracer. Thirty minutes later subjects received 3.6 mg 42Ca tracer intravenously. The molar concentrations of 42Ca and 44Ca tracers in a urine sample obtained 24 h after tracer administration were quantified by fast-atom-bombardment mass spectrometry and used to determine fractional absorption of the Ca from the supplement. Ca in the form of CCM had an increased fractional absorption (p less than 0.03) relative to Ca carbonate in healthy adolescents (36.2 vs 26.4%). This increase was not related to body size, sex, or indices of Ca metabolism.