Antioxidant, antimicrobial activities of flavonoids glycoside from Leucaena leucocephala leaves.

The study aimed to identify the chemical constituents of Leucaeana leucocephala leaves and evaluate the antioxidant and antimicrobial activities of the extract and compounds. An acylated flavanol glycoside, quercetin - 3-O-(2''-trans-p-coumaryl)-α-rhamnopyranosyl-(1'''→6'')-β-glucopyranoside (1) in addition to quercetin-3-O-α- rhamnopyranosyl-(1'''→2'')-β–glucopyranoside (2), quercetin-7-O-α–rhamnopyranosyl-(1'''→2'')-β-glucopyrano side(3), quercetin-3-O-α- rhamnopyranoside(4), quercetin-3-O-β–glucopyranoside (5), isovitexin( 6), vitexin (7) and quercetin (8) were isolated for the first time from the Leucaeana leucocephala. The antioxidant activity of the extract and the isolated compounds 1, 3 & 4 were evaluated by Reducing Power, FRAP, DPPH, Metal chelating and ABTS assays. Compound (3) recorded the highest antioxidant activity in comparison with the extract and other compounds. The extract and compound 1, 2, 3 and 5 were studied for their antimicrobial activity. Both the extract and compound 1 have significant activity against gm-ve bacteria, moderate to gm +ve and Candida and inactive towards fungi. The structures of compounds were elucidated on the basis of spectral analysis. L. leucocephala possess good antioxidant, antibacterial properties and could serve as free radical inhibitors or scavengers, acting possibly as primary antioxidants and have to be investigated for antiinflammatory and anticancer activities.

Antioxidant Properties, Secondary metabolites and Growth as affected by application of Putrescine and Moringa leaves extract on Jojoba plants.

This work aimed to study the effect of putrescine at (50, 100 and 200 ppm ) as a chemical growth regulator , moringa leaves extract ( 3.5%, 7% and 10 %) as a natural extract and control (distilled water ) on growth, photosynthetic pigments, phytochemicals and antioxidant capacity of jojoba plants grown in earthenware pots. Application of MLE (10 %) caused an increase in plant height by 103.24%, meanwhile (7 %) of MLE led to 4.08% increment in the branches number as compared to control plants. Chlorophyll a, b and carotenoids recorded the highest concentrations by treating with MLE (10 %) followed by putrescine (50 ppm).Total phenolic, flavonoid , tannin content and antioxidant activity of jojoba plants significantly increased with putrescine treatment at 50 ppm and these increments were 28.98%, 31.33%, 74.82% and 65.44%, respectively as compared to control plants. Also, foliar spray of MLE (7 %) led to highest increment of total phenolic, flavonoid and tannins (41.67%, 85.13% and 80.50%, respectively).Moringa leaves extract had the superiority in increasing reducing power ability it increased gradually by increasing moringa leaves extract concentration. Some changes in amino acids concentration were observed with putrescine (50and200 ppm) as well as total essential amino acids.