Triclopyr 3, 5, 6-trichloro-2-pyridinyl clean-up procedure from soil, sediment and water samples using SPE-HPLC-VWD

Triclopyr is a post emergence herbicide used to control woody plants. After application, the excess amount will enter the soil and water bodies and it is present in ppb level thus making extraction very difficult. The extraction of triclopyr 3, 5, 6-trichloro-2-pyridinyl residue from soil, sediment and water samples under different solid phase extraction (SPE) sorbent efficiency was studied for better recovery. Four different SPE sorbents i.e.: Oasis HLB, Water Sep-Pak, Cromabond (cation/anion PS-H+ /OH-), Isolute ENV+ and a series of solvent i.e. potassium dihydrogen phosphate (KH2PO4 0.1M), sodium hydroxide (NaOH 0.2M), potassium hydroxide (KOH 0.5 & 0.6M), ammonium acetate, methanol and water were used as extraction solution. Sample clean-up performance was evaluated using high performance liquid chromatography (HPLC, Agilent 1220 infinity LC) with variable wavelength detector (VWD) 290 nm. Cromabond®H+/OHcolumn with 0.6 M KOH was the most suitable for the clean-up in view of the overall feasibility of the analysis. The highest recovery was 89.32%

Structural and electrical characterisations of rapid thermal annealed thin silicon oxide films on silicon

Thin Solid Films3171-2219-222THSF

Distribution of dietary palm carotenes and their metabolites in the rabbit

10.1016/S0271-5317(97)00178-4Nutrition Research1711-121721-1731NTRS

Performance of Choline-Based Deep Eutectic Solvents in the Extraction of Tocols from Crude Palm Oil

Deep eutectic solvents are emerging green solvents that have potential in many separation processes. This study investigates the performance of choline-based deep eutectic solvents in the extraction of tocopherols and tocotrienols (collectively known as tocols) from palm oil, a major natural source of tocols. Deep eutectic solvents comprised of choline chloride salt and selected carboxylic acids as hydrogen bond donors were prepared and used in the extraction of tocols from crude palm oil by liquid-liquid extraction. Tocols concentration in the extracted product was at least double that in the control (8671 mg/kg compared to 3285 mg/kg, respectively). Increasing the amount of the deep eutectic solvents increased the tocols concentration in the extracted product up to 18,525 mg/kg, but the yields lowered from 4 % to less than 1 %. The tocols profile was significantly improved by the increase of the tocotrienols fraction in the products from 80.8 to 99.8 %. This study showed that unique interaction between the selected deep eutectic solvents with the tocols make it possible to selectively separate individual tocols in palm oil, where products with fractions rich in tocotrienols and low in tocopherols (particularly alpha-tocopherol) are favorable

Unusual indole alkaloid—epyrrole, —epyrone, and —carbamic acid adducts from Alstonia angustifolia

Three unusual natural products, viz., alstopirocine, a macroline alkaloid incorporating a substituted pyrrole moiety, pleiomaltinine, an alkaloide—pyrone adduct, and pleiomalicine, an alkaloid—carbamic acid adduct, were isolated from the Malayan Alstonia angustifolia. The alkaloid moiety in alstopirocine was alstomicine while that in pleiomaltinine and pleiomalicine was pleiocarpamine. The structures were determined by spectroscopic methods and in the case of pleiomaltinine, confirmed by X-ray diffraction analysis. Possible biogenetic pathways to these unusual compounds are presented

Structure, biological activity, and a biomimetic partial synthesis of the lirofolines, novel pentacylic indole alkaloids from Tabernaemontana

Two new pentacyclic indole alkaloids, lirofolines A and B, possessing a novel rearranged ibogan ring system, are obtained from two Malayan Tabernaemontana species ( Tabernaemontana corymbosa and Tabernaemontana divaricata) and the structures are established by analysis of the spectroscopic data. A biomimetic partial synthesis of lirofoline A from ibogaine via the Polonovski reaction is carried out. Lirofolines A and B showed significant activity in reversing multidrug resistance in vincristine-resistant KB cells (IC50 3.4 and 7.5 µg/ml, respectively)