In this paper we traced the possible influence of the solar flare of June 26, 1999 on the
ionosphere throughout the F2-layer parameters. This study concentrated on two parameters,
foF2, the critical frequency of the ordinary component of the F2-layer; and hc, the height of the
maximum obtained by fitting a theoretical h0F curve for the parabola of best fit to the observed
ordinary mode trace near foF2 and correcting for under-lying ionization. The results showed that
the relation between the amplitude of averaged sudden enhancements of the perturbations for
the critical frequency of the ionospheric F2 region, DfoF2 (for data obtained from 8 ionosonde stations),
and the duration of the flare is more applicable to the empirical formula given by Youssef
(2008). Since we found this relation is linear and has a very strong correlation. In addition, we
found that the relation between the average amplitude, of DfoF2, for the 8 selected ionosonde stations,
and the flare flux is not a linear. For the second parameter, hc, it was found that, the hc amplitude
depends on the location of the station on the Earth, and it reaches its maximum value during
the decay phase of the studied flare.

Soft corals of the genus Lobophytum, a marine invertebrate, have shown diverse biological activities as antiinflammatory, cytotoxic, and antibacterial. Our research is concerning with biological screening and discovering bioactive substances from the Red Sea soft coral Lobophytum pauciflorum. In vitro cyclooxygenase inhibitory activity using COX-1 and COX-2 kits and antimicrobial screening were carried out for n-hexane, dichloromethane, ethyl acetate and methanol fractions. The isolated compounds were elucidated using different spectroscopic methods including nuclear magnetic resonance and mass spectrometry. Also n-hexane fraction was subjected to GC/MS analysis. Bioassay guided fractionation resulted in isolation and characterization of two bio-active metabolites nephthenol (2) and gorgost-5-ene-3β-ol (3) with significant in vitro antiinflammatory activity against COX-1 and COX-2 compared to Indomethacin and Celecoxib. Four other compounds were also isolated: Heptadecan-1-ol (1), palmitic acid (4), stearic acid (5) and batilol (6). The isolated compounds showed antimicrobial activity ranging from 25 μg/ml to 50 μg/ml against the tested microorganisms. The fatty acid constituents of the n-hexane fraction were identified by GC/MS analysis; results revealed the presence of hexadecanoic acid, methyl ester as major saturated fatty acid and 7,10-hexadecadienoic acid, methyl ester as major unsaturated fatty acid.
Keywords: Lobophytum pauciflorum, gorgost-5-ene-3β-ol, nephthenol, COX-1, COX-2 and GC/MS.