Compositions and Ni-Cu-Platinum Group Element Tenors of Nova-Bollinger Ores with Implications for the Origin of Pt Anomalies in Platinum Group Element-Poor Massive Sulfides

The Nova-Bollinger Ni-Cu-platinum group element (PGE) deposit in the Fraser zone of the Albany-Fraser orogen consists of two main orebodies, Nova and Bollinger, hosted by the same tube-shaped intrusion but having distinctly different Ni tenors of around 6.5 and 4.8 wt %, respectively. Nova is also higher in Pd, but Cu and Pt tenors are similar. Both deposits have very low PGE tenors, with average Pd concentrations of 110 ppb in massive sulfide at Bollinger and 136 ppb at Nova. The Nova and Bollinger orebodies show relatively little internal differentiation overall on deposit scale but show strong differentiation into chalcopyrite-rich and chalcopyrite-poor regions at a meter scale. This differentiation is more prevalent at Nova, where massive sulfide-filled vein arrays are more extensively developed, and in massive ores, particularly veins, than in net-textured ores. Net-textured and disseminated ores have on average Ni and Cu grades and tenors similar to those of massive, semimassive, and breccia ores in the same orebody but a smaller range of variation, largely due to a more limited extent of sulfide liquid fractionation and higher average concentrations of Pt and Pd than adjacent massive ores. Unusually for differentiated magmatic sulfides, there is no systematic positive correlation between Pt, Pd, and Cu. A partial explanation for the lack of a Pd-Cu correlation is that Pd was partitioned into peritectic pentlandite in the middle stages of sulfide liquid solidification. This explanation is not applicable to Pt, as Pt characteristically forms its own phases rather than residing in base metal sulfides. PGE tenors are very low in both orebodies, very similar to those observed in other Ni-Cu-Co sulfide ores in orogenic settings, notably the Savannah and Savannah North orebodies. This depletion is attributed to sulfide retention in the mantle source of the parent magmas rather than to previous fractional extraction of sulfide liquid in staging chambers or feeder networks. The higher Ni and Pd tenors at Nova are attributed to reworking and upgrading of precursor sulfide liquid originally deposited upstream at the Bollinger site. Replicate analyses of multiple jaw-crusher splits returned highly variable Pt and Au assays but much smaller relative errors in the other PGEs. The poor Pt and Au reproducibilities are attributed to nugget effects, explicable by much of the Pt and Au in the samples being present in sparse Pt- and Au-rich grains. This is principally true for Pt in massive rather than disseminated ores, accounting for a strong contrast in the distribution of Pt/Pd ratios between the two ore types. Numerical simulation suggests that Pt is predominantly resident in Pt-rich platinum group minerals with grain diameters of 100 μm or more and that at the low (<100 ppb) concentrations in these ores, this results in most assays significantly underreporting Pt. This is likely to be true in other low-PGE ores, such that apparent negative Pt anomalies in massive ores may in such cases be attributable to sampling artifacts.

Potential Antidiabetic Effects of Extracts from Four Medicinal Plants Used in Burkina Faso by Inhibition of Alpha-Amylase

Background: The purpose of this study was to evaluate α-amylase inhibitory effects of hydroethanolic extracts of bark from Daniella oliveri, Sclerocarya birrea, Maranthes polyandra, and Pteleopsis suberosa to fight type-II diabetes. Methods: Compound extractions were performed by hydroethanol maceration followed by liquid-liquid fractionation with solvents. TLC profiling was carried out with different fractions. The inhibitory effects of plant extracts on α-amylase activity were determined using rice starch as a substrate. Results: TLC profiling of different fractions showed different phytochemical compounds. The hydroethanolic plant extracts exhibited dose-dependent inhibition of α-amylase. D. oliveri displayed competitive inhibition, M. polyandra and S. birrea showed uncompetitive inhibition and Pteleopsis suberosa exerted mixed-inhibition. M. polyandra extract exerted the highest inhibitory effect (IC50 = 0.5 mg/mL). Conclusions: The barks of M. polyandra exhibit a remarkable α-amylase inhibitory effect which can be a novel source of antidiabetic molecules.

A Simple Liquid-Liquid Fractionation (LLF) Method for Isolating Deoxyandrographolide dan Andrographolide from Herbs of Andrographis paniculata (Burm., F) Ness and Its Cytotoxic Activity on 3T3-L1 Preadipocyte Cells

The main bitter constituents of sambiloto (Androgaphis paniculata (Burm., F) Ness) are diterpene lactones, namely andrographolide and deoxyandrographolide which have been reported to have antidiabetic, cytotoxic, antiatherosclerosis, anti-inflammatory, and antimicrobial activity. There are many studies that performed the isolation of deoxyandrographolide and andrographolide from A. paniculata herbs, but most of them included several steps that make them not efficient. This research was conducted to do an isolation of deoxyandrographolide and andrographolide through liquid-liquid fractionation (LLF) due to its simplicity, low cost, and time efficient. The extraction of deoxyandrographolide and andrographolide from the herbs was carried out using chloroform as the solvent by using Soxhlet apparatus, and LLF was performed to isolate the compounds. The identities of the compounds were confirmed by TLC scanner compared to its standard references. Hence, these present methods were successfully isolated and determined deoxyandrographolide and andrographolide of A. paniculata. The compounds were also showed relatively moderate cytotoxicity on 3T3-L1 cell lines using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay, with LC50 of deoxyandrographolide and andrographolide; 29.3173 µg/mL and 37.7011 µg/mL, respectively.

Geochemical Features and Mineral Associations of Differentiated Rocks of the Norilsk 1 Intrusion

The purpose of this study is to show the patterns of distribution of disseminated sulfide in layered rocks based on the numerous geochemical and mineralogical data obtained for eight boreholes of the Norilsk intrusion (southern part of the Norilsk 1 deposit). There is a common trend of sulfide liquid fractionation in the Main Ore Horizon, which is composed of picritic and taxite (or olivine) gabbro-dolerites: the Ni/Cu in both rock types decreases down all sections, indicating an increase in the degree of fractionation of the sulfide liquid from top to bottom. On the contrary, the Ni/Fe ratios in pentlandite increase in this direction due to an increase in sulfur fugacity. However, picrite and taxite/olivine gabbro-dolerites are very distinctly separated by Ni/Cu values: these values are >1 in picritic gabbro-dolerite while they are always <1 in taxite/olivine gabbro-dolerite. These rock types are distinguished by sulfide assemblages. The first includes troilite, Fe-rich pentlandite, chalcopyrite, cubanite, talnahite, bornite and copper (low sulfur association); the second one is composed of monoclinic pyrrhotite, chalcopyrite, Ni-rich pentlandite and pyrite (high sulfur association). A two-stage magma injection with different ore specializations is supposed for picritic and taxite/olivine gabbro-dolerites.

POTENSI AKTIVITAS ANTIOKSIDAN EKSTRAK ETANOL DAN FRAKSI N-HEKSAN BUAH JERUK PAMELO (Citrus maxima (Burm) Merr) ASAL KABUPATEN PANGKEP

Pomelo citrus (Citrus maxima (Burm) Merr) is a fruit plant that has the potential to be developed for health. Pomelo fruit contains lycopene, flavonoids and vitamin C which can provide antioxidant activity. The purpose of this study was to determine the potential antioxidant activity of ethanol extract and fraction of n-hexane of pomelo citrus using quercetin as a comparison. Extraction of pomelo citrus fruit using the maceration method with liquid-liquid fractionation using water and n-hexane (1: 3 v / v). Testing of antioxidant activity using the DPPH (1,1-Diphenyl-2-picrylhidrazil) method is based on the ability of the sample to capture DPPH free radicals which are characterized by purple to yellow discoloration and a decrease in the absorbance value of DPPH which has reacted with samples in certain concentrations. Absorbance measurements using a UV-Vis spectrophotometer at a wavelength of 514,942 nm. The results showed that the IC50 value of quercetin was 6.55 µg / mL which was a strong antioxidant, while the IC50 value of the ethanol extract of pomelo citrus fruit was 2882.26 µg / mL and IC50 value of the n-hexane fraction of pomelo orange was 3668,44 µg / mL which is a weak antioxidant category. Kata kunci : Antioxidants, Ethanol Extract, n-Hexane Fraction, Pomelo citrus (Citrus maxima (Burm) Merr

Anti-Inflammatory Principles from Tamarix aphylla L.: A Bioassay-Guided Fractionation Study

Natural products have served as primary remedies since ancient times due to their cultural acceptance and outstanding biodiversity. To investigate whether Tamarix aphylla L. modulates an inflammatory process, we carried out bioassay-guided isolation where the extracts and isolated compounds were tested for their modulatory effects on several inflammatory indicators, such as nitric oxide (NO), reactive oxygen species (ROS), proinflammatory cytokine; tumour necrosis factor (TNF-α), as well as the proliferation of the lymphocyte T-cells. The aqueous ethanolic extract of the plant inhibited the intracellular ROS production, NO generation, and T-cell proliferation. The aqueous ethanolic crude extract was partitioned by liquid-liquid fractionation using n-hexane (n-C6H6), dichloromethane (DCM), ethyl acetate (EtOAc), n-butanol (n-BuOH), and water (H2O). The DCM and n-BuOH extracts showed the highest activity against most inflammatory indicators and were further purified to obtain compounds 1–4. The structures of 3,5-dihydroxy-4’,7-dimethoxyflavone (1) and 3,5-dihydroxy-4-methoxybenzoic acid methyl ester (2) from the DCM extracts; and kaempferol (3), and 3-hydroxy-4-methoxy-(E)-cinnamic acid (4) from the n-BuOH extract were elucidated by different spectroscopic tools, including MS, NMR, UV, and IR. Compound 2 inhibited the production of ROS and TNF-α, whereas compound 3 showed inhibitory activity against all the tested mediators. A better understanding of the potential aspect of Tamarix aphylla L. derivatives as anti-inflammatory agents could open the door for the development of advanced anti-inflammatory entities.