Determination of Amino Acids in Medicinal Plants from Southern Sonora, Mexico

Purpose: To analyze the amino acid contents of some plants used in traditional medicine in Southern Sonora, Mexico by using high performance liquid chromatography (HPLC).Methods: The plant samples (Jutuki, Zizyphus obtusifolia A.Gray; Jito, Forchammeria watsonii Rose; Barchata, Lycium berlandieri Dunal; Citabaro, Vallesia glabra Link; Mangle Rojo, Rhizophora mangle L and Tatachinole, Tournefortia hartwegiana Steud) were dehydrated at room temperature and ground to a fine powder. Amino acid analysis was performed by  reversed-phase HPLC. Elution was carried out with a gradient mobile phase of sodium acetate 0.1 M and methanol (9:1). Samples were derived with ophthalaldehyde (OPA) and detected by fluorescence at 360(Ex)/455(Em) wavelengths.Results: HPLC analysis resulted in a reliable detection and peak resolution. Tatachinole samples show the greater amino acid concentration (7.83 to 58.17 nM). Fifteen amino acids were detected in plant samples, with  aspartic acid (Asp), glutamic acid (Glu), serine (Ser), glycine (Gly), alanine (Ala) and leucine (Leu) (43.55, 44.84, 29.60, 58.17, 43.05 and 38.73 nM, respectively) presenting the highest concentrations.Conclusion: The amino acids - Asp, Glu, Ser, Gly, Ala and Leu - are  naturally involved in osmolyte synthesis, cell metabolism, ammonia  detoxification, antioxidant activity and alkaloid synthesis, suggesting that the therapeutic properties of these Southern Sonora plants may have some links to their amino acid composition.Keywords: Amino acid profile, Medicinal plants, Osmolytes, Drought/saline stres

δ15N value does not reflect fasting in mysticetes.

The finding that tissue δ15N values increase with protein catabolism has led researchers to apply this value to gauge nutritive condition in vertebrates. However, its application to marine mammals has in most occasions failed. We investigated the relationship between δ15N values and the fattening/fasting cycle in a model species, the fin whale, a migratory capital breeder that experiences severe seasonal variation in body condition. We analyzed two tissues providing complementary insights: one with isotopic turnover (muscle) and one that keeps a permanent record of variations in isotopic values (baleen plates). In both tissues δ15N values increased with intensive feeding but decreased with fasting, thus contradicting the pattern previously anticipated. The apparent inconsistency during fasting is explained by the fact that a) individuals migrate between different isotopic isoscapes, b) starvation may not trigger significant negative nitrogen balance, and c) excretion drops and elimination of 15N-depleted urine is minimized. Conversely, when intensive feeding is resumed in the northern grounds, protein anabolism and excretion start again, triggering 15N enrichment. It can be concluded that in whales and other mammals that accrue massive depots of lipids as energetic reserves and which have limited access to drinking water, the δ15N value is not affected by fasting and therefore cannot be used as an indicatior of nutritive condition