Aa Zaki

Assessment of Anti-Quorum Sensing Activity for Some Ornamental and Medicinal Plants Native to Egypt

This study investigated the effects of some plant extracts on the bacterial communication system, expressed as quorum sensing (QS) activity. Quorum sensing has a directly proportional effect on the amount of certain compounds, such as pigments, produced by the bacteria. Alcohol extracts of 23 ornamental and medicinal plants were tested for anti-QS activity by the Chromobacterium violaceum assay using the agar cup diffusion method. The screening revealed the anti-QS activity of six plants; namely the leaves of Adhatoda vasica Nees, Bauhinia purpurea L., Lantana camara L., Myoporum laetum G. Forst.; the fruits of Piper longum L.; and the aerial parts of Taraxacum officinale F.H. Wigg.

Cytotoxic steroidal saponins from Panicum turgidum Forssk

Three new bidesmosidic cholestane-type steroidal glycosides, 16-O-β-d-glucopyranosyl-cholest-5-en-3β,16β-diol-22-one-3-O-α-l-rhamnopyranosyl-(1→2)-O-[(β-d-glucopyranosyl(1→4)]-O-β-d-glucopyranoside (1), 16-O-β-d-glucopyranosylcholest-5-en-3β,16β-diol-22-one-3-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-glucopyranoside (2), and 16-O-β-d-glucopyranosylcholestan-3β,16β-diol-6,22-dione-3-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-glucopyranoside (3) were isolated from a methanolic extract of Panicum turgidum. In addition four known compounds, pennogenin 3β-O-α-l-rhamnopyranosyl-(1→2)-O-[α-l-rhamnopyranosyl-(1→4)-O-α-l-rhamnopyranosyl-(1→4)]-O-β-d-glucopyranoside (4), yamogenin 3β-O-α-l-rhamnopyranosyl-(1→2)-O-[α-l-rhamnopyranosyl-(1→4)]-O-β-d-glucopyranoside (5), yamogenin 3β-O-α-l-rhamnopyranosyl-(1→2)-O-[α-l-rhamnopyranosyl-(1→4)-O-α-l-rhamnopyranosyl-(1→4)]-O-β-d-glucopyranoside (6), and pennogenin 3β-O-α-l-rhamnopyranosyl-(1→2)-O-[α-l-rhamnopyranosyl-(1→4)]-O-β-d-glucopyranoside (7) were also isolated and characterized. Their structures were established using extensive spectroscopic methods including 1D and 2D NMR and HRESIMS. The isolated compounds were screened for cytotoxicity towards a panel of mammalian cell lines and 4-7 were found to be cytotoxic.

Biological Activities of Oleanolic Acid Derivatives from Calendula officinalis Seeds

Phytochemical examination of butanol fraction of Calendula officinalis seeds led to the isolation of two compounds identified as 28‐O‐β‐D‐glucopyranosyl‐oleanolic acid 3‐O‐β‐D–glucopyranosyl (1→3)‐β‐D‐glucopyranosiduronic acid (CS1) and oleanolic acid 3‐O‐β‐D–glucopyranosyl (1→3)‐β‐D‐glucopyranosiduronic acid (CS2). Biological evaluation was carried out for these two compounds such as melanin biosynthesis inhibitory, hyaluronic acid production activities, anti obesity using lipase inhibition and adipocyte differentiation as well as evaluation of the protective effect against hydrogen peroxide induced neurotoxicity in neuro‐2A cells. The results showed that, compound CS2 has a melanin biosynthesis stimulatory activity; however, compound CS1 has a potent stimulatory effect for the production of hyaluronic acid on normal human dermal fibroblast from adult (NHDF‐Ad). Both compounds did not show any inhibitory effect on both lipase and adipocyte differentiation. Compound CS2 could protect neuro‐2A cells and increased cell viability against H2O2. These activities (melanin biosynthesis stimulatory and protective effect against H2O2 of CS2 and hyaluronic acid productive activities of these triterpene derivatives) have been reported for the first time. Copyright

PPARα and γ Activation Effects of New Nor-triterpenoidal Saponins from the Aerial Parts of Anabasis articulata

Anabasis articulata, traditionally used to treat diabetes, is rich in saponin content. This study was performed to investigate the agonistic effect of its saponins on peroxisome proliferator-activated receptor-α and peroxisome proliferator-activated receptor-γ in human hepatoma (HepG2) cells to explore the possibility of the involvement of these nuclear receptors in the mechanism of the antidiabetic effect of the plant. Chemical investigation of the n-butanol fraction resulted in the isolation of three new and one known 30-noroleanane triterpenoid saponins. The structures of the new compounds were elucidated as 3β-hydroxy,23-aldehyde-30-norolean-12,20(29)-dien-28-oic acid-28-O-β-D-glucopyranosyl ester (1: ), 3β-O-D-galactopyranosyl-23-aldehyde-30-norolean-12,20(29)-dien-28-oic acid-28-O-β-D-glucopyranosyl ester (2: ), and 3β-O-D-xylopyranosyl-30-norolean-12,20(29)-dien-28-oic acid 28-O-β-D-glucopyranosyl ester (3: ), while the known 30-nortriterpenoidal saponin was identified as boussingoside E (4: ). Although, the isolated saponins (1:  - 4: ) did not show > 1.5-fold activation of peroxisome proliferator-activated receptor-γ, but two of them (1: and 3: ) activated peroxisome proliferator-activated receptor-α to the higher extents of 2.25- and 1.86-fold, respectively. These results suggest that the reported antidiabetic action of the isolated saponins may not solely involve the activation of peroxisome proliferator-activated receptor-γ. However, the agonistic activity of the n-butanol fraction of A. articulata (1.71-fold induction) and two of its saponins (1: and 3: ) towards peroxisome proliferator-activated receptor-α may be beneficial in the cardiovascular condition that is closely associated with diabetes and other metabolic disorders.

Antiprotozoal and Cytotoxicity Studies of Fractions and Compounds from Enantia chlorantha

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Benin, Benin City, 300001, Nigeria. National Center for Natural Products Research, Institute of Pharmaceutical Sciences, University of Mississippi, 38677, USA. Pharmacognosy Department, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt. Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC 27506, USA. Department of Bio-Molecular Sciences, School of Pharmacy, University of Mississippi, 38677, USA. Office of Global engagement, University of Mississippi, 38677, USA.

A new lignan from Zygophyllum aegyptium

Zygophyllum aegyptium is a perennial, woody undershrub with evergreen succulent leaves. This species is distributed in the Mediterranean region of Egypt, Tunisia, and Cyprus. The genus Zygophyllum represents the largest genus in the family Zygophyllaceae. Many species of the genus Zygophyllum have been used in skin cleansing, removal of horny patches on the skin as well as for ailments, such as rheumatism, gout, asthma, or hypertension. The diversity in chemical constituents reported from Zygophyllum such as, quinovic acid and its saponins, pterocarpans, flavonoids, and tannins, prompted us to investigate Z. aegyptium which has barely been investigated for its chemical constituents.