UHPLC-ESI-Orbitrap-HR-MS Analysis of Cyclopeptide Alkaloids From Ziziphus joazeiro

Ziziphus joazeiro Mart., popularly known as “juazeiro”, is a tree widely found in the northeast of Brazil. It is commonly used as an anti-inflammatory, antibacterial, antifungal, and analgesic agent. The stem extract exhibited, beside cytotoxic properties, substantial activity against the Gram-negative bacterium Allivibrio fischeri. UHPLC-ESI-Orbitrap-HR-MS analysis of the alkaloidal fraction of the crude methanolic stem extract of this species enabled the detection and putative identification of sixteen cyclopeptide alkaloids (CPAs), including four possibly new structures. According to the MS2 fragmentation analysis, from the sixteen identified CPAs, three possess a type-Ia1, one a type-Ia2, and twelve a type-Ib cyclopeptide alkaloid core. The structures of paliurine-C and -D were supported by NMR data.

Ziziphus oenoplia Mill.: A systematic review on ethnopharmacology, phytochemistry and pharmacology of an important traditional medicinal plant

Background: Ziziphus oenoplia Mill. (Family- Rhamnaceae) an important shrub, often found throughout the hot regions of tropical Asia and northern Australia, is commonly well known as Jackal Jujube in English. It is a folk herbal medicine used as an abdominal pain killer and anti-diarrhoeal agent,. Objective: The review aims to provide up-to-date information on the vernacular information, botanical characterization, distribution, ethnopharmacological uses, pharmacological activities, and chemical constituents of Z. oenoplia for possible exploitation of treatment for various diseases and to suggest future investigations. Method: This review was performed by studying online resources relating to Z. oenoplia and diverse resources, including scientific journals, books, and worldwide accepted databases from which information was assembled to accumulate significant information and relevant data at one place. Results: Investigations on Z. oenoplia have been focused on its pharmacological activities, including its antimicrobial, antidiabetic, antihepatotoxic, antiulcer, antiplasmodial, anticancer, wound healing, anthelmintic, antioxidant, analgesic and antinociceptive, hypolipidemic activity, anti-inflammatory, immunomodulatory and antidiarrheal activities. Phytochemical studies resulted in the isolation of fatty acids, flavonoids, phenols, pentacyclic triterpenes, hydroxy carboxylic acids, aliphatic hydroxy ether, and cyclopeptide alkaloids. Conclusions: Most of the ethnopharmacological relevance of Z. oenoplia is justified but more need to be studied. Further investigations are necessary to fully understand the mode of action of the active constituents and to exploit its preventive and therapeutic potentials.

In Silico Activity Identification of Cyclo Peptide Alkaloids from Zizyphus Spina-Christi Species Against Sars-Cov-2 Main Protease

The COVID-19 has spread worldwide and become an international pandemic. The promising target for drug discovery of COVID-19 was SARS-CoV-2 Main Protease (Mpro), that has been successfully crystallized along with its inhibitor. The discovery of peptide-based inhibitors may present better options than small molecules for inhibitor SARS-CoV-2 Mpro. Natural compounds have such a wide potential and still few explored, Zizyphus spina-christi is one of the medicinal plants that have many pharmacological activities and contains a peptide compound from alkaloids class, i.e. cyclopeptide alkaloids, that is interesting to explore as SARS-CoV-2 Mpro inhibitor. The compound structure was drawn and optimized using density functional theory 3-21G method. The protein chosen was the high resolution of SARS-CoV-2 MPro receptor (1.45 Å) with PDB ID: 6WNP, in complex with boceprevir. Molecular docking simulation was performed using Autodock4 with 100 numbers of GA run, the validation methods assessed by RMSD calculation. Furthermore, the prediction of pharmacological activity spectra was carried out using the PASS Prediction server. The results showed RMSD value was 1.98 Å, this docking method was valid. The binding energy of all compounds showed better results than the native ligand (Boceprevir). The in silico PASS prediction results indicated that all compounds showed antiviral activity. Some compounds showed protease inhibitory activity, i.e Ambiphibine-H, Franganine, and Mauritine-A, and the highest Pa (Predicted activity) value showed by Mauritine-A compounds. It can be concluded that the cyclopeptide compounds of Zizyphus spina-christi were indicated to have a potential as COVID-19 therapy targeting SARS-CoV-2 Mpro.

New bioactive cyclopeptide alkaloids with rare terminal unit from the root bark ofZiziphus cambodiana

Six new 14-membered ring cyclopeptide alkaloids, cambodines A–F (1–6), and two known compounds, frangufoline (7) and lotusanine B (8), were isolated from the root bark extract ofZiziphus cambodianaPierre.