ABSTRACT
Five new B-seco-limonoids, namely toonanoronoids A-E (1-5), in conjunction with three previously reported compounds, were isolated from the EtOAc extract of the twigs and leaves of Toona ciliata var. yunnanensis. Their structures were elucidated through comprehensive spectroscopic and X-ray crystallographic analysis. The cytotoxic activities of new compounds against five human tumor cell lines (HL-60, SMMC-7721, A549, MCF-7, and SW480) were screened, Compounds 4 and 5 exerted inhibition toward two tumor cell lines (HL-60, SW-480) with IC50 values between 1.7 and 5.9 µM.
Subject(s)
Antineoplastic Agents, Phytogenic , Limonins , Phytochemicals , Plant Leaves , Toona , Humans , Molecular Structure , Cell Line, Tumor , Antineoplastic Agents, Phytogenic/pharmacology , Antineoplastic Agents, Phytogenic/isolation & purification , Plant Leaves/chemistry , Limonins/isolation & purification , Limonins/pharmacology , Limonins/chemistry , Phytochemicals/isolation & purification , Phytochemicals/pharmacology , China , Toona/chemistry , Plant Stems/chemistryABSTRACT
Many different types of toxins are produced by the fungus, Alternaria alternata (Fr.) Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-induced inhibitory effects of the toxin produced by A. alternata on the rose aphid, Macrosiphum rosivorum, when the toxin was applied to leaves of the rose, Rosa chinensis. The results demonstrated that the purified crude toxin was non-harmful to rose plants and rose aphids, but had an intensive inhibitory effect on the multiplication of aphids. The inhibitory index against rose aphids reached 87.99% when rose plants were sprayed with the toxin solution at a low concentration. Further results from bioassays with aphids and high performance liquid chromatography (HPLC) analyses demonstrated that tenuazonic acid (TeA) was one of the most important resistance-related active components in the crude toxin. The content of TeA was 0.1199% in the crude toxin under the HPLC method. Similar to the crude toxin, the inhibitory index of pure TeA reached 83.60% 15 d after the rose plants were sprayed with pure TeA solution at the lower concentration of 0.060 µg/ml, while the contents of residual TeA on the surface and in the inner portion of the rose plants were only 0.04 and 0.00 ng/g fresh weight of TeA-treated rose twigs, respectively, 7 d after the treatment. Our results show that TeA, an active component in the A. alternata toxin, can induce the indirect plant-mediated responses in rose plants to intensively enhance the plant's resistances against rose aphids, and the results are very helpful to understand the plant-mediated interaction between fungi and insects on their shared host plants.
Subject(s)
Aphids/physiology , Plant Diseases/parasitology , Rosa/drug effects , Rosa/parasitology , Sphingosine/administration & dosage , Tenuazonic Acid/administration & dosage , Animals , Aphids/drug effects , Disease Resistance , Plant Diseases/prevention & control , Treatment OutcomeABSTRACT
The search for active toxins for managing weeds or plant diseases is believed to be a promising avenue of investigation. However, the effects of Alternaria toxins on insects have just begun to be investigated. Bioactivities of toxins from four strains of Alternaria alternata on Rosa chinensis and rose aphid Macrosiphum rosivorum were tested in the present study. At a concentration of 50.0 µg/ml, the crude extract (toxin) of strain 7484 was found not to be harmful to rose plants with excised leaf-puncture method (P≥0.079), and rose plants showed enhanced resistance to rose aphids when this Alternaria toxin was sprayed on the plants (P≤0.001). However, this toxin caused no detrimental effects on aphids in insecticidal bioassay at a concentration of 10.0 to 160.0 µg/ml (P≥0.096). Therefore, the Alternaria toxin had significantly induced the resistance of rose plants against rose aphids, demonstrating that the resistance mechanism triggered by the Alternaria toxin in the rose plant may also be used by the plant to defend itself against insects. Further bioassays aimed to discover the olfactory responses of aphids to the toxin-induced volatiles of host plants. The aphids were significantly more attracted to both volatiles emitted and collected from control rose plants than to both volatiles emitted and collected from the toxin-treated rose plants (P≤0.014). This result showed that the toxin-induced resistance related to the volatile changes of host plants.
Subject(s)
Alternaria/chemistry , Aphids , Mycotoxins , Plant Diseases/parasitology , Rosa , Animals , Biological Assay , Plant Diseases/prevention & controlABSTRACT
AIM: To explore the changes of mRNA and protein expressions of heart-type fatty acid binding protein (H-FABP) in rat ischemic myocardium at different intervals ischemia. METHODS: 60 SD male rats weighing 250-350 g, were randomly divided into one sham-operated group and five study groups (group A1, A2, A3, A4, A5, the left coronary artery of rats has been ligated for 1 h, 2 h, 4 h, 6 h, 12 h respectively). Myocardil samples from infarct zone, ischemic and non-ischemic zone, were obtained for histology examination, and the mRNA for H-FABP in ischemic myocardial tissue were determined by RT-PCR. Serum free fatty acid(FFA) was determined by colorimetric method. RESULTS: Compared to sham hearts, H-FABP mRNA expression were significantly decreased in ischemia zone of AMI rat hearts (P < 0.05), especially in rats underwent 4 h ischemia and 6 h ischemia (P < 0.01). Serum FFA were significantly increased in AMI rats relative to sham rats (P < 0.05). CONCLUSION: Significant down-regulated heart-type fatty acid binding protein after myocardial ischemia might play an important role in myocardial injury and energy metabolism disorder.
