Growth under elevated air temperature alters secondary metabolites in Robinia pseudoacacia L. seedlings in Cd- and Pb-contaminated soils.

Plant secondary metabolites play a pivotal role in growth regulation, antioxidant activity, pigment development, and other processes. As the global climate changes, increasing atmospheric temperatures and contamination of soil by heavy metals co-occur in natural ecosystems, which alters the pH of rhizosphere soil and influences the bioavailability and mobility of metals. Elevated temperatures in combination with heavy metals are expected to affect plant secondary metabolites, but this issue has not been extensively examined. Here, we investigated secondary metabolites in Robiniapseudoacacia seedlings exposed to elevated temperatures using a passive warming device in combination with Cd- and Pb-contaminated soils. Heavy metals significantly stimulated the accumulation of saponins, phenolic compounds, and flavonoids in leaves and stems; alkaloid compounds increased in leaves and decreased in stems, and condensed tannins fluctuated. Elevated temperatures, alone and in combination with Cd and Pb, caused increases in secondary metabolites in the plant tissues. Phenolic compounds showed the greatest changes among the secondary metabolites and significant interactive effects of temperature and metals were observed. These results suggest that slightly elevated temperature could enhance protective and defense mechanisms of Robinia pseudoacacia seedlings exposed to heavy metals by stimulating the production of secondary metabolites.

A new triterpene lactone from the roots of Patrinia scabiosaefolia.

A new triterpene lactone named patrinolide A (1) has been isolated from the roots of Patrinia scabiosaefolia (Valerianaceae). Its structure was determined to be 11beta,21beta-dihydroxy-3-oxooleanan-28,13beta-olide on the basis of spectral analysis, including 2D-NMR techniques. Key words: Patrinia scabiosaefolia, Valerianaceae, Lactone, Patrinolide, 11beta,21beta-dihydroxy-3-oxooleanan-28,13beta-olide.

Phenolic compounds from Duchesnea chrysantha and their cytotoxic activities in human cancer cell.

Five phenolic compounds were isolated from 80% aq. acetone extract of Duchesnea chrysantha. Their cytotoxicities were screened by the colorimetric tetrazolium assay (MTT assay). Gallic acid, methyl caffeate, protocatechuic acid and pedunculagin mildly inhibited the survival of PC14 and MKN45 human cancer cell. Brevifolin carboxylic acid showed a strong cytotoxic activity.

Effects of thyroidectomy on the metabolic clearance rate of prolactin and prolactin release in the rat.

The effects of thyroidectomy on both the secretion of rat prolactin (PRL) in vivo and the release of PRL from rat anterior pituitary glands (Aps) in vitro in the absence of ovarian steroids were studied. Rats were ovariectomized (Ovx) 42 days after thyroidectomy or sham-thyroidectomy. On day 15 following ovariectomy the rats were either decapitated for examining the in vitro release of PRL from AP or anesthetized for measuring the metabolic clearance rate (MCR) of rat PRL. After decapitation, blood samples were collected and APs were incubated with or without the extract of rat medial basal hypothalamus (rHE) at 37 degrees C for 4 h. The MCR of iodinated rat PRL was determined by a single injection method. Blood samples were collected by heart puncture at frequent intervals. Serum PRL concentrations of decapitated thyroidectomized-ovariectomized (TX-Ovx) rats were 56% lower than those found in Ovx rats. Thyroidectomy in Ovx rats resulted in a significant reduction of the spontaneous release of PRL from AP. The rHE decreased PRL levels in the medium after incubation with APs from sham Tx rats, but not those from Tx rats. MCR of PRL was reduced in Ovx rats by thyroidectomy. These results indicate that thyroidectomy reduces the spontaneous release of rat PRL by AP and secretion rate of rat PRL in the absence of ovarian steroids.