Search

Four isolates of Botryococcus braunii Kutzing were isolated from the Nile River in Egypt. The morphological examinations and results of 5.8S rRNA gene sequences confirmed that EG-Bb01 (JN580448.1), EG-Bb02 (JN580449.1), EG-Bb03 (JN580450.1) and EG-Bb04 (JN580451.1) are B. braunii. The isolates were cultivated in modified Chu 13 medium and incubated for 8 weeks at 25±1 °C under light intensity of 16 ± 3 μmol m−2 s−1 with 16:8 h light: dark cycle. The dry weight biomass ranged between 0.382 gl−1 and 0.628 gl−1 for the isolates EG-Bb03 and EG-Bb01. Also, the hydrocarbon production (% w/w) varied significantly (P ≤ 0.05) between 33% (EG-Bb03) and 53% (EG-Bb01). GC/MS analysis revealed marked qualitative and quantitative variations in hydrocarbon profile of B. braunii isolates. A total of 24 C16 C31 different compounds were identified. The hydrocarbon of the four isolates was mainly composed of aliphatic hydrocarbons with the odd carbon numbered C25 C31, indicating that these isolates are a typical race A of B. braunii. Isolate EG-Bb01 maintained the highest content of C25 C31 hydrocarbons of (36.44%). The hexahydrofarnesylacetone (C18H38O) ketone was detected in the four isolates with different proportions ranged between 0.216% (EG-Bb01) and 13.86% (EG-Bb04). Meanwhile, the alcohol hexacosanol C26H54O (31.52%) was only detected in the isolate EG-Bb03.

This study involves the development and characterization of a series of sodium alginate-based pH-responsive hydrogel microspheres encapsulating poly( d , l -lactic-co-glycolic acid) (PLGA) nanoparticles (NPs). The effect of the drying technique (air- or freeze-drying) on the size of the developed particles was determined. Swelling characteristics at different pH values, in vitro biodegradation and moisture contents of both air-dried and freeze-dried hydrogel particles were investigated. The effect of drying method on the morphology of the particles was also studied using SEM and AFM. Then, the developed alginate-PLGA particles were evaluated as potential carriers, through a new approach, to improve the dissolution, bioavailability and oral sustained release of silymarin, as a model of hydrophobic natural therapeutics. The used silymarin was isolated from the seeds of some native milk thistle (Silybum marianum) ecotypes of delta Egypt and was characterized with the aid of several analytical techniques including; 1H NMR, UV and FTIR. The obtained data showed a considerable effect of the alginate content and the drying method onto the characteristics of the prepared particles. Also, the results demonstrated that the developed alginate-based hydrogel microparticles encapsulating silymarin-loaded PLGA NPs can be used as biodegradable carriers that can confer sustained oral release of silymarin in addition to enhancing its overall dissolution and oral bioavailability.

Separation of the extract of Maerua oblongifolia afforded, in addition to known compounds, three lupane triterpenoids; one of them is new natural product, which was identified, by one and two dimensional NMR, MS and IR spectra, as lup-20(29)-en-3β,30-diol.

5-Benzoylethyl barbituric acid derivatives 2a-c were prepared as useful precursors for the synthesis of pyrimidine fused heterocycles. Their behaviour as 1,5-diketocompounds towards aniline derivatives afforded the pyrimidoquinoline derivatives 6a-e. On the other hand, fusion of o -substituted anilines with 1,3-dimethyl barbituric acid derivatives 8a,b gave the corresponding benzazoles 10a-e. Furthermore, the reaction of 1,3-dimethyl barbituric acid (1) with catechol/K3|Fe(CN)6| or β-ketoester (19)/SiCl4 gave the benzofuro adduct 13a and the diphenylphenyl barbituric acid derivative 18, respectively.

The extract of Schoenus nigricans afforded, in addition to a known stilbene and a known prenylflavanone, four new stilbenes and two new prenylflavanones. The structures were elucidated on the basis of spectral data.

The aerial parts of Francoeuria crispa gave, in addition to known sesquiterpene lactones, two new ones. From the polar parts a large amount of two diterpene glycosides derived from ent-kauren-19-oic acid were obtained.

An extract of the aerial parts of Cleome africana afforded in addition to known compounds two triterpenes of the dammarane type. The structures were elucidated using high field NMR spectroscopy.

A new sesquiterpene ether, named dactyloxene D, has been isolated from Laurencia obtusa . The structure was identified by spectroscopic methods and stereochemistry was established by NOE difference spectroscopy.

Reichardia tingitana var. orientalis afforded, in addition to lupeol, taraxasterol, and the corresponding acetates, three sesquiterpene lactones of the guaianolide type including a new glucoside. The structures were elucidated by spectral methods.

Artemisia monosperma afforded four flavonoids, two acetylenes, eight p -hydroxyacetophenone derivatives and three p -coumaric acid derivatives, two of them being new. The structures were elucidated by spectral methods. The flavonoids present are naringenin 7-methyl ether, eriodictyol 7-methyl ether, quercetin 3,7-dimethyl ether and quercetin 7,3′-dimethyl ether.

A reinvestigation of the aerial parts of Pyrethrum santolinoides afforded, in addition to known compounds, four new sesquiterpene lactones, three germacranolides and an eudesmanolide. The structures were elucidated by high field 1H NMR techniques.

Achillea fragrantissima afforded, in addition to several known glaucolides, five new compounds whose structures were elucidated by high field 1 H NMR spectroscopy.

Two new iridoid glucoside esters were isolated from Anarrhinum orientale and identified by spectral methods as 6- O -nerol-8-oyl-antirrinoside and 6′- O -cinnamoyl-antirrinoside.

The aerial parts of Iphiona scabra afforded in addition to some previously isolated xylosides two new ones derived from 10- epi -cubebol and α-elemol. The structures were elucidated by NMR spectroscopy.