A lectin from the green Venezuelan marine alga Caulerpa serrulata was extracted with phosphate buffered saline (PBS) using cold steeping infusion (CSI) and by grinding with liquid nitrogen (GLN). The proteins were precipitated using solid ammonium sulfate. Both the crude extracts and ammonium sulfate precipitated proteins were tested for hemagglutinins using native and papain-treated human red blood cell suspensions in isotonic saline solution. Purification of lectins was achieved using affinity chromatography-sugar-epoxy-sepharose 6B and molecular weight was assessed by size exclusion chromatography using Bio-gel ® P-100 and SDS-PAGE with 2-mercaptoethanol. IEF-urea 8M was also evaluated. Using CSI it was shown that the marine alga released hemagglutinating compounds into the solutions; the same hemagglutinating compounds were also obtained by GLN. Ammonium sulfate precipitated proteins exhibited agglutinating activity against native and papain-treated human red blood cells. Temperature and EDTA were shown to affect dramatically the lectin activity towards red blood cells. A lectin was purified efficiently and the molecular weight calculated as approximately 78,000 Daltons. The CSI technique demonstrated that the alga could be returned to an active metabolic state by immersion in a simple buffer after having been kept dormant by freezing at-20ºC for long periods. It was also shown that the alga was releasing bioactive compounds into the solutions and, therefore, this procedure is being suggested as a good, gentle, non-disruptive extraction technique and we postulate CSI as a possible bioreactor for the continuous production of bioactive compounds from green marine algae.

Haemagglutinins have been isolated from two red marine algae Bryothamnion seaforthii and B. triquetrum, which were harvested from the Caribbean Sea, Falcon State, Venezuela. The mass spectra of the haemagglutinins isolated from B. seaforthii showed five monomer peaks (9057.4-9088.8 Da) and those from B. triquetrum showed three peaks (8981.5-8990.2 Da). Isoelectric focusing, under denaturing conditions, gave rise to multiple bands for the haemagglutinins of both species but only one band was observed under native conditions. Gel permeation experiments suggest that the monomer haemagglutinins can readily associate to form dimers, trimers and tetramers. The haemagglutinins agglutinate papainized human A, B and O erythrocytes; the activity is inhibited by glycoconjugates, but not by simple sugars, and is maintained after heating to temperatures up to 90 C. The amino acid sequence of the haemagglutinin from B. seaforthii has been determined together with a partial sequence for that from B. triquetrum. The isolation, and some characterization, of haemagglutinins from B. seaforthii and B. triquetrum, collected from the Ceara coast of Brazil, have previously been reported. Some differences and similarities of these macromolecules obtained from the two different locations are discussed.

Banana and plane are the most important fruits in world trade, behind citric plants. In this work we studied the antioxidant capacity of banana and plane varieties of fruits obtained from interspecies crossed varieties of Musa acuminata and Musa balbisiana, named Harton plane, Cavendish banana, and Manzano banana. With this purpose we evaluated banana and plane crude extracts using the ferrous ion oxidation with xylenol orange method, the thiobarbituric acid method, determination of antioxidant activity, and effect on superoxide anion and hydroxyl radical and the radicals generated by ultraviolet light. The experiments showed that all extracts have the capacity to decrease the concentrations of lipid hydroperoxides and malondialdehyde, produced in the lipid peroxidation process, in a manner comparable to that of other widely studied antioxidants like melatonin and vitamin E. Moreover, all extracts had the capacity to inhibit the generation of superoxide anion, hydroxyl radical, and the radicals generated by ultraviolet light. When antioxidant activity was calculated, a value was found that was equivalent to a concentration of uric acid between 0.20 and 0.30 mM at the highest concentration of extract used, with uric acid being a potent antioxidant at 1 mM.