Distributions of surface sediments surrounding the Antarctic Peninsula and its environmental significance

We analyzed grain size composition to provide information on the types and distributions as well as depositional varieties of marine surface sediments from the area surrounding the Antarctic Peninsula. The samples retrieved from the study area contain gravel, sand, silt and clay. As suggested by bathymetry and morphology, the study area is characterized by neritic, hemipelagic and pelagic deposits. The glacial-marine sediments can be divided into two types, residual paratill and compound paratill, which are primarily transported by glaciers and as ice-rafted debris. Ocean current effects on deposition are more obvious, and the deposit types are distributed consistently with terrain variations

Discovery of unusual dimeric piperazyl cyclopeptides encoded by a Lentzea flaviverrucosa DSM 44664 biosynthetic supercluster

Rare actinomycetes represent an underexploited source of new bioactive compounds. Here, we report the use of a targeted metabologenomic approach to identify piperazyl compounds in the rare actinomycete Lentzea flaviverrucosa DSM 44664. These efforts to identify molecules that incorporate piperazate building blocks resulted in the discovery and structural elucidation of two dimeric biaryl-cyclohexapeptides, petrichorins A and B. Petrichorin B is a symmetric homodimer similar to the known compound chloptosin, but petrichorin A is unique among known piperazyl cyclopeptides because it is an asymmetric heterodimer. Due to the structural complexity of petrichorin A, solving its structure required a combination of several standard chemical methods plus in silico modeling, strain mutagenesis, and solving the structure of its biosynthetic intermediate petrichorin C for confident assignment. Furthermore, we found that the piperazyl cyclopeptides comprising each half of the petrichorin A heterodimer are made via two distinct nonribosomal peptide synthetase (NRPS) assembly lines, and the responsible NRPS enzymes are encoded within a contiguous biosynthetic supercluster on the L. flaviverrucosa chromosome. Requiring promiscuous cytochrome p450 crosslinking events for asymmetric and symmetric biaryl production, petrichorins A and B exhibited potent in vitro activity against A2780 human ovarian cancer, HT1080 fibrosarcoma, PC3 human prostate cancer, and Jurkat human T lymphocyte cell lines with IC50 values at low nM levels. Cyclic piperazyl peptides and their crosslinked derivatives are interesting drug leads, and our findings highlight the potential for heterodimeric bicyclic peptides such as petrichorin A for inclusion in future pharmaceutical design and discovery programs.Fil: Li, Chunshun. University Of Hawaii; Estados UnidosFil: Hu, Yifei. University Of Hawaii; Estados Unidos. Washington University in St. Louis; Estados UnidosFil: Wu, Xiaohua. University Of Hawaii; Estados UnidosFil: Stumpf, Spencer D.. Washington University in St. Louis; Estados UnidosFil: Qi, Yunci. Washington University in St. Louis; Estados UnidosFil: D'Alessandro, John M.. Washington University in St. Louis; Estados UnidosFil: Nepal, Keshav K.. Washington University in St. Louis; Estados UnidosFil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Cao, Shugeng. University Of Hawaii; Estados UnidosFil: Blodgett, Joshua A.V.. Washington University in St. Louis; Estados Unido

Verbenanone, an octahydro-5H-chromen-5-one from a Hawaiian-plant associated fungus FT431

Verbenanone (1), a new secondary metabolite with a unique (4aS,8aS)-octahydro-5H-chromen-5-one moiety has been obtained from the endophytic fungus FT431, which was isolated from the native Hawaiian plant Verbena sp. The structure of compound 1 was characterized based on NMR and MS spectroscopic analysis. The absolute configuration (AC) of compound 1 was determined by Mosher acids. Compound 1 was tested against A2780 and A2780cisR, but it was inactive.Fil: Li, Chunshun. University Of Hawaii At Hilo; Estados Unidos. University of Hawaii Cancer Center; Estados UnidosFil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Turkson, James. University of Hawaii Cancer Center; Estados UnidosFil: Cao, Shugeng. University Of Hawaii At Hilo; Estados Unidos. University of Hawaii Cancer Center; Estados Unido

Laurenidificin, a new brominated C15-acetogenin from the marine red alga Laurencia nidifica

A new brominated C_(15-acetogenin, namely, laurenidificin, was isolated from the marine red alga Laurencia nidifica. Its structure was determined on the basis of spectroscopic method

Two new polyketides from Hawaiian endophytic fungus Pestalotiopsis sp. FT172

Two new polyketides, pestalotiotones A (1) and B (2) were isolated from the cultured broth of Pestalotiopsis sp. FT172. The structures of compounds 1 and 2 were determined by analysis of HRMS and NMR spectroscopic data. The absolute configurations of compound 1 were assigned by Mosher reaction, J-based configuration analysis, and DP4 NMR calculations. Both compounds were tested against cancer cell lines, pathogenic fungi and bacteria.Fil: Li, Chunshun. University of Hawaii at Manoa; Estados UnidosFil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Yoshida, Wesley. University of Hawaii at Manoa; Estados UnidosFil: Cao, Shugeng. University of Hawaii at Manoa; Estados Unido

Reducing Compressibility of the Expansive Soil by Microbiological-Induced Calcium Carbonate Precipitation

Most of the research studies on the improvement of expansive soils are focused on reducing their expansive properties; however, there are few studies on the impact of the soil compressibility after the improvement. In this paper, through indoor high-pressure consolidation tests, the recent microbial-induced calcium carbonate precipitation (MICP) technology is studied to improve the compression characteristics of the expansive soil. The significant effect of different microbial concentrations (achieved by different number of treatments) on the compression deformation is revealed with the hyperbolic function that involves two parameters with clear physical meanings. In particular, after 6 times of treatment with the microbial solution, the compression characteristics of the expansive soil reach the best improvement effect; continuing to increase the number of microbial treatments is, otherwise, not conducive to improving the soil compression performance. Also, a dramatical increase of the structural strength of the microbial-treated expansive soil is presented and investigated. Moreover, we performed a scanning electron microscope (SEM) experiment and confirmed the existence of crystals due to mineralization. This study shows that MICP is an effective and environmentally friendly means of reducing the compressibility of the expansive soil

A New N-methoxypyridone from the Co-Cultivation of Hawaiian Endophytic Fungi Camporesia sambuci FT1061 and Epicoccum sorghinum FT1062

A new N-methoxypyridone analog (1), together with four known compounds, was isolated from the co-culture of Hawaiian endophytic fungi Camporesia sambuci FT1061 and Epicoccum sorghinum FT1062. The structure of the new compound was elucidated as 11S-hydroxy-1-methoxyfusaricide (1) by extensive spectroscopic analysis and comparison with the literature. The absolute configuration of 1 was determined by comparison with the experimental and calculated ECD spectra. The absolute configuration of compound 3 was investigated and renamed as (+)-epipyridone by comparison of the optical rotation and CD spectrum with those of 1. The other known compounds were identified as epicoccarine B (2), D8646-2-6 (4), and iso-D8646-2-6 (5). Compounds 4 and 5 showed modest inhibitory activity towards pathogenic fungi. Epicoccarine B (2) inhibited A2780 and TK-10 with an IC50 value of 22 μM.Fil: Li, Chunshun. University Of Hawaii At Hilo; Estados Unidos. University of Hawaii Cancer Center; Estados UnidosFil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Yang, Baojun. University of Hawaii Cancer Center; Estados UnidosFil: Turkson, James. University of Hawaii Cancer Center; Estados UnidosFil: Cao, Shugeng. University Of Hawaii At Hilo; Estados Unidos. University of Hawaii Cancer Center; Estados Unido

Sphaerialactonam, a γ-lactam–isochromanone from the Hawaiian endophytic fungus Paraphaeosphaeria sp. FT462

Reinvestigation of the endophytic fungus Paraphaeosphaeria sp. FT462 from the Hawaiian plant Lycopodiella cernua (L.) Pic. Serm led to the isolation and identification of a unique γ-lactam-isochromanone (1). The structure of 1 was determined by NMR, MS spectroscopic analysis, and quantum chemical calculations of NMR. The compound was tested inactive against A2780 and A2780cisR.Fil: Huang, Peng. University Of Hawaii At Hilo; Estados Unidos. Anhui University of Chinese Medicine; ChinaFil: Li, Chunshun. University Of Hawaii At Hilo; Estados Unidos. University of Hawaii Cancer Center; Estados UnidosFil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Turkson, James. University of Hawaii Cancer Center; Estados UnidosFil: Cao, Shugeng. University Of Hawaii At Hilo; Estados Unidos. University of Hawaii Cancer Center; Estados Unido