The new ansa macrolide antibiotics 1 to 4 have been isolated from cultures of a Micromonospora sp. obtained from a marine sediment. Rifamycins 1 and 2 are the first natural ansa macrolides to have a 3-amino substituent. Sporalactams A (3) and B (4) are comprised of a heterocylic core 5 and a 14-membered ansa bridge that are both unprecedented. Sporalactam B (4) shows selective and potent inhibition of Mycobacterium tuberculosis.
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http://dx.doi.org/10.1021/acs.orglett.6b03619 | DOI Listing |
Sci Rep
January 2025
College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, P. R. China.
Aeolian sandy soil is barren and readily leads to low fertilizer utilization rates and yields. Therefore, it is imperative to improve the water and fertilizer retention capacity of these soils. In this paper, three kinds of biochar (rice husk, corn stalk, and bamboo charcoal) and bentonite were used as amendments in the first year of the experiment.
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January 2025
Department of Biology, Boston University, Boston, MA, USA.
Spatial changes in benthic community structure have been observed across natural gradients in deep-sea ecosystems, but these patterns remain under-sampled on seamounts. Here, we identify the spatial composition and distribution of coral and sponge taxa on four sides of a single central Pacific equatorial "model" seamount within the US EEZ surrounding the Howland and Baker unit of the Pacific Islands Heritage Marine National Monument. This seamount rises from 5,000 + m to mesophotic depths of 196 m, and is influenced by the Equatorial Undercurrent.
View Article and Find Full Text PDFEnviron Res
January 2025
Southern California Coastal Water Research Project, Costa Mesa, CA, 92626.
The concentration, character, and distribution of microplastics in coastal marine environments remain poorly understood, with most research focusing on the abundance of microplastics at the sea surface. To address this gap, we conducted one of the first comprehensive assessments of microplastic distribution through the marine water column and in the benthic sediment during the wet and dry season in the coastal waters of the San Pedro Shelf, Southern California, USA. Microplastic concentrations in the water column did not vary significantly across season but were significantly higher in nearshore environments and at the surface of the water column.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
Suganthi Devadason Marine Research Institute, Tuticorin, Tamil Nadu, India; Manonmaniam Sundaranar University, Abishekapatti, Tirunelveli, Tamil Nadu, India.
This research investigated the relationship between microplastic accumulation and the sediment texture in seagrass meadows across the selected coastal regions of Tuticorin. Sixteen sediment samples were collected by SCUBA divers utilizing a stainless steel grab sampler. Findings indicate significantly elevated microplastic concentrations in seagrass sediments when compared to unvegetated areas.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China.
Investigations of the spatial-temporal variations of nutrients within mangrove coastal zones are essential for assessing the environmental status of an aquatic ecosystems. However, major processes controlling nitrate cycle along the submarine groundwater discharge (SGD) pathway from the mangrove areas to adjacent tidal creek remain underexplored. A time series measurement over a 25 h tidal cycle was conducted in Qinglan Bay tidal creek (Hainan Island, China).
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