ABSTRACT
In order to study the alkaloids from branches and leaves of Ervatamia hainanensis, silica gel, ODS, Sephadex LH-20 and HPLC chromatography were used to obtain six alkaloids from the branches and leaves of E. hainanensis with use of. Based on the physicochemical properties and spectral data, their structures were identified as 10-hydroxydemethylhirsuteine(1), 3R-hydroxycoronaridine(2), 3-(2-oxopropyl)coronaridine(3), pandine(4), 16-epi-vobasine(5), and 16-epi-vobasinic acid(6). Among them, compound 1 was a new monoterpenoid indole alkaloid, and compounds 5 and 6 were obtained from this plant for the first time.
Subject(s)
Alkaloids , Chromatography, High Pressure Liquid , Molecular Structure , Plant Leaves , TabernaemontanaABSTRACT
Four alkaloids were isolated from the total alkaloids of the twigs and leaves of Alstonia yunnanensis (Apocynaceae) by using silica gel, ODS, Sephadex LH-20, and HPLC chromatography. Structures were determined by physical, chemical and spectroscopic methods and identified as N4-methylpseudoakuammigine (1), pseudoakuammigine (2), vinorine (3), picraline (4). Among them, compound 1 is a new monoterpenoid indole alkaloid.
ABSTRACT
Four new corynanthe-type alkaloids, meloslines C-F (1-4), together with four known ones (5-8) were isolated from the roots of Alstonia scholaris. Their structures including absolute configurations were elucidated by extensive spectroscopic analysis and electronic circular dichroism (ECD) calculation. Compounds 1 and 2 exhibited potent vasorelaxant activity on endothelium-intact renal arteries precontracted with KCl.
ABSTRACT
Nrf2(nuclear factor erythroid 2-related factor 2), a transcription factor, is sensitive to oxidative stress. It drives the production of endogenous antioxidant enzymes and detoxifying enzymes to prevent damage from poisonous substance. NF-κB (nuclear factor- kappa light chain enhancer of B cells) is an essential transcription factor for regulation of immuno-inflammatory reaction. The two pathways interact to maintain intracellular redox homeostasis under physiological conditions. Nrf2 deficient mice exhibit greater induction of NF-κB, whereas NF-κB also inhibit Nrf2 activity at function level. Previous studies indicate the molecular mechanism of drug induced liver injury (DILI) is the imbalance of Nrf2 and NF-κB pathways. Recently, many bioactive natural products could active Nrf2 and inhibit NF-κB. Hence, the interaction of the two pathways may be targets for the treatment and prevention of DILI. The aims of this review are to dissect the interactive molecular mechanism between Nrf2 and NF-κB in DILI, and explore how natural pharmacological active products regulate Nrf2 and NF-κB pathways.
ABSTRACT
The physiological response and bioaccumulation of 2-year-old Panax notoginseng to cadmium stress was investigated under a hydroponic experiment with different cadmium concentrations (0, 2.5, 5, 10 μmol · L(-1)). Result showed that low concentration (2.5 μmol · L(-1)) of cadmium could stimulate the activities of SOD, POD, APX in P. notoginseng, while high concentration (10 μmol · L(-1)) treatment made activities of antioxidant enzyme descended obviously. But, no matter how high the concentration of cadmium was, the activities of CAT were inhibited. The Pn, Tr, Gs in P. notoginseng decreased gradually with the increase of cadmium concentration, however Ci showed a trend from rise to decline. The enrichment coefficients of different parts in P. notoginseng ranked in the order of hair root > root > rhizome > leaf > stem, and all enrichment coefficients decreased with the increase of concentration of cadmium treatments; while the cadmium content in different parts of P. notoginseng and the transport coefficients rose. To sum up, cadmium could affect antioxidant enzyme system and photosynthetic system of P. notoginseng; P. notoginseng had the ability of cadmium enrichment, so we should plant it in suitable place reduce for reducing the absorption of cadmium; and choose medicinal parts properly to lessen cadmium intake.
Subject(s)
Cadmium , Pharmacokinetics , Toxicity , Hydroponics , Panax notoginseng , Metabolism , Photosynthesis , Superoxide Dismutase , MetabolismABSTRACT
The physiological effects of Panax notoginseng seedlings under simulated drought stress by PEG 6000 on antioxidant enzymes, osmotic substances and root activities were studied. The results showed that the activity of POD and APX in roots and leaves kept rising with increasing processing concentration and time. However, on the one hand, at the same processing time, SOD in roots and leaves firstly increased and then decreased with the increase of processing concentration. On the other hand, at the same processing concentration, SOD kept rising with the extension of processing time. In addition, the activity of CAT in roots and leaves tended to increase with the increasing concentration at the same processing time, while it increased at first and then decreased with the extension of time at the same concentration. The activity of SOD and APX in stem did not change obviously, whereas CAT activity in stem increased with the increasing processing time and concentration. With the increase of processing concentration and the extension of processing time, the MDA, soluble protein, proline content and root activity in leaves and roots apparently rose. Moreover, fluorescence signal of H2O2 and NO in root tip enhanced as the processing concentration increased after treated for 1 d. In summary, P. notoginseng seedlings could deal with drought stress by means of adjusting the system of antioxidant enzyme, permeating stress substances and impeded stress signal substances. Thus, when the concentration of PEG 6000 was more than 5%, it would have harm on P. notoginseng seedlings.