ABSTRACT
Variable-charge (v-c) soils in subtropical areas contain considerable amounts of iron/aluminum (Fe/Al) oxides that can strongly influence the fate of heavy metals in agricultural ecosystems. However, the relationship between heavy metal accumulation in vegetables and the geochemical factors associated with v-c soils in subtropical regions remains unknown. The present study investigated heavy metal accumulation under field conditions in the Pearl River Delta (PRD) by measuring the content of 8 heavy metals (zinc (Zn), arsenic (As), copper (Cu), mercury (Hg), lead (Pb), chromium (Cr), nickel (Ni) and cadmium (Cd)) in 43 pairs of v-c soil and vegetable (balsam pear and cowpea) samples. Soil physicochemical properties including pH, texture, organic matter and oxide minerals (Fe2O3, SiO2, Al2O3, CaO, MgO, K2O and Na2O) were also analyzed. Heavy metal accumulation from soil to vegetables was assessed based on bioconcentration factors (BCFs). The results showed that soil extractable Fe, oxide minerals and chemical weathering indices of v-c soils strongly affected heavy metal accumulation, whereas the content of Zn, Cu, Cr and Ni in vegetables was strongly affected by the soil clay content. Significant correlations were found between the BCFs of heavy metals and oxide minerals. However, no significant relationship was found between pH and heavy metal accumulation (except for Cu) in balsam pear and cowpea. Correlation analyses showed that a lower oxalate/DCB- extractable Fe content might indicate greater heavy metal (Zn, Cu, Hg, Cr and Ni) accumulation in vegetables. Therefore, it can be deduced that oxalate/DCB- extractable Fe content is a critical geochemical factor that determines the bioavailability of heavy metals and that iron biogeochemical cycles play vital roles in the fate of heavy metals in vegetable fields in this area. These findings provide new insights into the behaviors and fate of heavy metals in subtropical v-c soils and can be used to develop possible guidelines for vegetable safety management.
Subject(s)
Environmental Monitoring , Fabaceae/chemistry , Metals, Heavy/analysis , Pyrus/chemistry , Soil Pollutants/analysis , Agriculture , China , Rivers , Soil/chemistryABSTRACT
Two DNA cleavage agents, meso-dihydroguaiaretic acid (1) and isobavachalcone (2) together with the known alpha-ylangene, beta-sitosterol, daucosterol, pentacosane, hexacosanic acid and cerotic acid 1-monoglyceride were isolated from the stem barks of Kadsura ananosma Kerr for the first time. Compounds 1 and 2 showed relaxation of supercoiled DNA to nicked DNA. 1 represented a new structural type of DNA cleavage agent, while 2 was reported to show DNA strand-scission activity for the first time. 1 also showed significant cytotoxic effect on Hela and Leukemia cells in vitro.
Subject(s)
Chalcones/chemistry , Chalcones/pharmacology , DNA/drug effects , Guaiacol/analogs & derivatives , Kadsura/chemistry , Lignans/chemistry , Lignans/pharmacology , Cell Line, Tumor , DNA/chemistry , DNA, Superhelical/chemistry , DNA, Superhelical/drug effects , Guaiacol/chemistry , Guaiacol/pharmacology , HeLa Cells , Humans , Leukemia/drug therapy , Leukemia/pathology , Magnetic Resonance Spectroscopy , Mass Spectrometry , Nucleic Acid Conformation , Plant Bark/chemistry , Plant Stems/chemistryABSTRACT
The lignans, gomisin G (1), schisantherin A (2), benzoylgomisin Q (3) and isoanwulignan (4) were isolated from the stems of Schisandra henryi. Compound 1 showed moderate DNA strand scission activity and significant cytotoxic effect on leukemia and Hela cells in vitro. Compound 1 represents a new type of DNA strand scission agent.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , DNA/chemistry , Lignans/pharmacology , Schisandra/chemistry , Antineoplastic Agents, Phytogenic/chemistry , Cell Line, Tumor , Humans , Lignans/chemistry , Molecular StructureABSTRACT
Two new 18(13-->12)-abeo-lanostane triterpenoid acids, ananosic acids B (1) and C (2), were isolated from the stems of Kadsura anaosma. Their structures were elucidated by spectral studies and chemical transformation. Compounds 1 and 2 were evaluated for cytotoxicity using CCRF-CEM leukemia cells and HeLa cells.
Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Drugs, Chinese Herbal/isolation & purification , Kadsura/chemistry , Lanosterol/isolation & purification , Plants, Medicinal/chemistry , Triterpenes/isolation & purification , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Drug Screening Assays, Antitumor , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/pharmacology , HeLa Cells , Humans , Inhibitory Concentration 50 , Lanosterol/analogs & derivatives , Lanosterol/chemistry , Lanosterol/pharmacology , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Plant Stems/chemistry , Triterpenes/chemistry , Triterpenes/pharmacology , Tumor Cells, CulturedABSTRACT
Four known lanostane triterpenoids, schiprolactone A (1), schisanlactone B (2), nigranoic acid (3) and schisandronic acid (4) were isolated from the stems of Schisandra henryi for the first time. Their structures were characterized by IR, MS and NMR techniques. Compounds 1, 2 and 4 showed moderate cytotoxic activity against Leukemia cells in vitro. Cytotoxic activity of compounds 1-4 showed IC50 of 0.0097, 0.01, 0.097 and 0.0099 micromol/mL respectively toward Leukemia cells and IC50 of 0.097, 0.1, 0.097 and 0.099 micromol/mL toward Hela cells respectively. It is the first report that these compounds possess cytotoxic activity on Leukemia and Hela cells.
