Analisis Keberhasilan Reklamasi berdasarkan Keputusan Menteri Energi dan Sumber Daya Mineral Nomor 1827 Tahun 2018 pada Lahan Bekas Tambang Air Jelitik 3 PT TIMAH Tbk Kabupaten Bangka

PT Timah Tbk is a mining industry company which produces the tin metal. A mining former area which is chosen as the research location is Lahan Air Jelitik 3. This research aims to analyze the success of Lahan Air Jelitik 3’s reclamation based on Matrik 16 and Matrik 17 of Keputusan Menteri Energi Sumber Daya Mineral Nomor 1827 Tahun 2018. The research starts with collecting the primary data which consists of 43 and 29 coordinate points of Lahan Air Jelitik 3’s adjustment and revegetation, the length and width of 22 erosion in Blok 1, 24 erosion in Blok 2 and 4 landslide in both blocks, the height and diameter of 35 primary plants and the length of 5 cover crops. Those primary data and secondary data are processed by calculating the broad realization of Lahan Air Jelitik 3’s adjustment and revegetation, the amount of plants, the average of plant’s height and diameter, the stability of area and valuating the success of adjustment area, the success of revegetation, the success of last completion based on Matrik 16, also calculating the success reclamation value based on Matrik 17. The result of data processing shows the success value of adjustment and hoard area is 0.5, top soil’s spreading is 0.91, erosion and sedimentation’s control is 0, cover crop’s revegetation is 0.86, fast growing plant’s revegetation is 0.1765, local plant’s revegetation is 0.726, acid mine drainage’s management is 0, plant’s closure is 0.1059 and plant’s maintenance is 0.333. The reclamation’s success percentage 50.65% in Lahan Air Jelitik 3 PT Timah Tbk shows that the reclamation in that area is not good enough and the area needs improvement especially in plant’s maintenance, erosion and sedimentation’s control and acid mine drainage’s management

Macrocyclization by Nickel-Catalyzed, Ester-Promoted, Epoxide-Alkyne Reductive Coupling: Total Synthesis of (−)-Gloeosporone

Ringing the changes: The total synthesis of the title compound centers around a novel strategy that employs a nickel(0)–phosphine complex and triethyl borane in an efficient closure of a 14-membered ring through C--C bond formation (see scheme; cod=cyclooctadiene). The synthesis was accomplished in 10 steps and in approximately 9 % overall yield.National Institute of General Medical Sciences (U.S.) (GM-72566)National Science Foundation (U.S.) (CHE-9809061)National Science Foundation (U.S.) (DBI-9729592)National Institutes of Health (U.S.) (1S10RR13866-01

Expanding the palette of phenanthridinium cations

5,6-Disubstituted phenanthridinium cations have a range of redox, fluorescence and biological properties. Some properties rely on phenanthridiniums intercalating into DNA, but the use of these cations as exomarkers for the reactive oxygen species (ROS), superoxide, and as inhibitors of acetylcholine esterase (AChE) do not require intercalation. A versatile modular synthesis of 5,6-disubstituted phenanthridiniums that introduces diversity by Suzuki–Miyaura coupling, imine formation and microwave-assisted cyclisation is presented. Computational modelling at the density functional theory (DFT) level reveals that the novel displacement of the aryl halide by an acyclic N-alkylimine proceeds by an SNAr mechanism rather than electrocyclisation. It is found that the displacement of halide is concerted and there is no stable Meisenheimer intermediate, provided the calculations consistently use a polarisable solvent model and a diffuse basis set

Antiplasmodial Activities of Homogentisic Acid Derivative Protein Kinase Inhibitors Isolated from a Vanuatu Marine Sponge Pseudoceratina sp.

As part of our search for new antimalarial drugs in South Pacific marine sponges, we have looked for inhibitors of Pfnek-1, a specific protein kinase of Plasmodium falciparum. On the basis of promising activity in a preliminary screening, the ethanolic crude extract of a new species of Pseudoceratina collected in Vanuatu was selected for further investigation. A bioassay-guided fractionation led to the isolation of a derivative of homogentisic acid [methyl (2,4-dibromo-3,6-dihydroxyphenyl)acetate, 4a] which inhibited Pfnek-1 with an IC50 around 1.8 μM. This product was moderately active in vitro against a FcB1 P. falciparum strain (IC50 = 12 μM). From the same sponge, we isolated three known compounds [11,19-dideoxyfistularin-3 (1), 11-deoxyfistularin-3 (2) and dibromo-verongiaquinol (3)] which were inactive against Pfnek-1. Synthesis and biological evaluation of some derivatives of 4a are reported

CXCR2 chemokine receptor antagonism enhances DOP opioid receptor function via allosteric regulation of the CXCR2–DOP receptor heterodimer

Opioid agonists have a broad range of effects on cells of the immune system, including modulation of the inflammatory response, and opioid and chemokine receptors are co-expressed by many white cells. Hetero-oligomerization of the human DOP opioid and chemokine CXCR2 receptors could be detected following their co-expression by each of co-immunoprecipitation, three different resonance energy transfer techniques and the construction of pairs of individually inactive but potentially complementary receptor G-protein α subunit fusion proteins. Although DOP receptor agonists and a CXCR2 antagonist had no inherent affinity for the alternative receptor when either receptor was expressed individually, use of cells that expressed a DOP opioid receptor construct constitutively, and in which expression of a CXCR2 receptor construct could be regulated, demonstrated that the CXCR2 antagonist enhanced the function of DOP receptor agonists only in the presence of CXCR2. This effect was observed for both enkephalin- and alkaloid-based opioid agonists, and the effective concentrations of the CXCR2 antagonist reflected CXCR2 receptor occupancy. Entirely equivalent results were obtained in cells in which the native DOP opioid receptor was expressed constitutively and in which expression of the isolated CXCR2 receptor could be induced. These results indicate that a CXCR2 receptor antagonist can enhance the function of agonists at a receptor for which it has no inherent direct affinity by acting as an allosteric regulator of a receptor that is a heterodimer partner for the CXCR2 receptor. These results have novel and important implications for the development and use of small-molecule therapeutics

Skin sensitization in silico protocol

The assessment of skin sensitization has evolved over the past few years to include in vitro assessments of key events along the adverse outcome pathway and opportunistically capitalize on the strengths of in silico methods to support a weight of evidence assessment without conducting a test in animals. While in silico methods vary greatly in their purpose and format; there is a need to standardize the underlying principles on which such models are developed and to make transparent the implications for the uncertainty in the overall assessment. In this contribution, the relationship of skin sensitization relevant effects, mechanisms, and endpoints are built into a hazard assessment framework. Based on the relevance of the mechanisms and effects as well as the strengths and limitations of the experimental systems used to identify them, rules and principles are defined for deriving skin sensitization in silico assessments. Further, the assignments of reliability and confidence scores that reflect the overall strength of the assessment are discussed. This skin sensitization protocol supports the implementation and acceptance of in silico approaches for the prediction of skin sensitization

Enzyme-Catalyzed Macrocyclization of Long Unprotected Peptides

A glutathione S-transferase (GST) catalyzed macrocyclization reaction for peptides up to 40 amino acids in length is reported. GST catalyzes the selective SNAr reaction between an N-terminal glutathione (GSH, γ-Glu-Cys-Gly) tag and a C-terminal perfluoroaryl-modified cysteine on the same polypeptide chain. Cyclic peptides ranging from 9 to 24 residues were quantitatively produced within 2 h in aqueous pH = 8 buffer at room temperature. The reaction was highly selective for cyclization at the GSH tag, enabling the combination of GST-catalyzed ligation with native chemical ligation to generate a large 40-residue peptide macrocycle.Massachusetts Institute of Technology (MIT startup funds)National Institutes of Health (U.S.) (grant GM101762)Damon Runyon Cancer Research Foundation (Award)Sontag Foundation (Distinguished Scientist Award)Amgen Inc. (Summer Graduate Research Fellowship

Iterative Assembly of Macrocyclic Lactones using Successive Ring Expansion Reactions

Macrocyclic lactones can be prepared from lactams and hydroxyacid derivatives via an efficient 3- or 4-atom iterative ring expansion protocol. The products can also be expanded using amino acid-based linear fragments, meaning that macrocycles with precise sequences of hydroxy- and amino acids can be assembled in high yields by 'growing' them from smaller rings, using a simple procedure in which high dilution is not required. The method should significantly expedite the practical synthesis of diverse nitrogen containing macrolide frameworks

HEMT's Design for Applications beyond 100GHz

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