Initiation of Flowering and Changes in Endogenous Inhibitors and Promoters in Olive Buds as a Result of Chilling

Olive trees require a period of chilling temperatures, either diurnally fluctuating, or at a constant—but definite—level before inflorescences develop. In this study, bud and leaf samples were taken at weekly intervals during this critical period from trees receiving temperatures favorable for flowering and from trees under temperature conditions known to prevent flowering. Extracts were obtained from these samples, separated by paper chromatography and the different growth-active materials were bioassayed by the mung bean rooting test for the presence of promoters and inhibitors. Extracts from buds on trees under conditions unfavorable for flowering generally consisted only of promoters. Extracts from buds on trees placed under conditions favorable for flowering showed a definite and consistent pattern for the presence of rooting inhibitors and promoters. Within one or two weeks after being placed under such conditions a strong inhibitor band appeared from R_f 0.50 to 0.70. This persisted for 6 to 7 weeks, gradually decreasing in intensity, followed by promoters at these bands. During this period all other bands, at different R_f values, showed strong promoters. Extracts from leaves on shoots under temperature regimes favorable for flowering showed a pattern like the buds in the appearance and disappearance of inhibitors and at the same R_f values but with about one week lag in time. Bud extracts from defoliated shoots on trees under temperature conditions known to result in inflorescence production failed to show the characteristic inhibitor pattern associated with flowering. Such defoliated shoots do not form inflorescences.     

Antioxidant enzymes of Pseudochlorella pringsheimii under two stressors: variation of SOD Isoforms activity

Journal of Plant Research - Algae are always facing the challenge of exposure to different stress conditions, therefore raising challenges of adaptation for survival. In this context, the growth...     

Synthesis of some quinazolinones inspired from the natural alkaloid L-norephedrine as EGFR inhibitors and radiosensitizers

A set of quinazolinones synthesized by the aid of L-norephedrine was assembled to generate novel analogues as potential anticancer and radiosensitizing agents. The new compounds were evaluated for their cytotoxic activity against MDA-MB-231, MCF-7, HepG-2, HCT-116 cancer cell lines and EGFR inhibitory activity. The most active compounds 5 and 6 were screened against MCF-10A normal cell line and displayed lower toxic effects. They proved their relative safety with high selectivity towards MDA-MB-231 breast cancer cell line. Measurement of the radiosensitizing activity for 5 and 6 revealed that they could sensitize the tumour cells after being exposed to a single dose of 8 Gy gamma radiation. Compound 5 was able to induce apoptosis and arrest the cell cycle at the G2-M phase. Molecular docking of 5 and 6 in the active site of EGFR was performed to gain insight into the binding interactions with the key amino acids.     

Spectroscopic,electrochemical, docking and molecular dynamics studies on the interaction of three oxovanadium (IV) Schiff base complexes with bovine serum albumin and their cytotoxicity against cancer

This study was designed to investigate the interaction of three oxovanadium (IV) Schiff base complexes with bovine serum albumin (BSA) by means of various spectroscopic and electrochemical methods along with molecular docking study and molecular dynamics simulations. Binding constants were estimated by fluorescence and UV-Vis spectroscopy. The results indicated a good affinity of the complexes for BSA in which furyl derivative had more activity. Molecular docking study showed that these complexes have the similar binding modes and located within subdomain IB in site III of BSA. The supporting of molecular docking and molecular dynamics results by experimental data, confirms the validity of the interactions data obtained by these methods. Biological activity against cancer cell showed that furyl derivative has higher activity than other complexes. Pharmaceutical analysis also showed that, these complexes potentially can be used as anticancer agents.     

Natural occurrence of mycotoxins in different spices in Egypt

A total of 120 different samples belonging to 24 kinds of spices collected from different places atAssiut Governorate (Egypt) were examined for the natural occurrence of mycotoxins. TLC analysis of spice extracts revealed the presence of aflatoxins (8–35 μg/kg) in 16 samples of anise, black pepper, caraway, black cumin, fennel, peppermint, coriander and marjoram, sterigmatocystin (10–23 μg/kg) in ten samples of red pepper, caraway, cumin and marjoram and citrinin (8–12 ⧎g/kg) in two samples of black cumin, while ochratoxin A and zearalenone could not be detected.     

Utilization of cheese whey for lipid and sterol production by some isolates of xerophilous fungi

One hundred and two isolates of 30 species and 4 varieties belonging to 4 genera of xerophilous fungi were cultivated on cheese whey. In fourteen species and one variety, all isolates (45) failed to grow on the cheese whey. The other species and varieties (16 and 3) of fungi were able to grow and to accumulate variable amounts of lipid and sterol on whey.Aspergillus aureolatus, Eurotium repens, E. rubrum andEmericella nidulans var.lata produced high levels of lipids, total sterols and ergosterol whileE. tonophilum proved to be superior in the production of lipid (38±8%) of dry mycelial mass), total sterol (20±4%) and ergosterol (13±3%).