Oleanolic acid (pentacyclic triterpenes) as a potential candidate for α-glycosidase inhibition activity

Background: Diabetes mellitus is a common health dilemma worldwide and is characterized by hyperglycemia. Inhibition in the activity of one of the digestive tract enzymes α-glucosidase is one of the therapeutic approaches to hydrolyze carbohydrates into glucose using natural agents. Many natural compounds with α-glucosidase inhibitory activity have transpired to be secondary metabolites. Monotheca buxifolia, native to Pakistan is a major medicinal tree, which has been known for its extensive pharmacological activities.Methods: α-glucosidase activity of ten isolated compounds (lupeol, lupeol acetate, betulin, β-sitosterol, β-amyrin, oleanolic acid, vanillic acid, protocatechuic acid, kaempferol and quercetin) from lipophilic hexane fraction of M. buxifolia (stem and leaves) was assessed against α-glucosidase enzyme using acarbose as a control.Results: All ten compounds hold α-glucosidase inhibition potential (91-99%). However, IC50 (half-maximal inhibitory concentration) values of oleanolic acid (5 µM) were 8-fold lower than that of acarbose. Moreover, inhibition potencies of lupeol (15.87 µM), β-amyrin (18.14 µM) betulin (21.49 µM), quercetin (23.47 µM), and lupeol acetate (29.45 µM) were much stronger than the inhibitory effect obtained from acarbose (38.25 µM).Conclusion: Oleanolic acid of M. buxifolia exhibited a potent inhibitory effect against α-glucosidase, therefore, oleanolic acid may be utilized in medicinal formulations against diabetic disorders.Keywords: Diabetes mellitus; Enzyme inhibition; Medicinal plants; Pentacyclic triterpenes

Comparative antimicrobial activity of clove and fennel essential oils against food borne pathogenic fungi and food spoilage bacteria

Antifungal and antibacterial activities of essential oils obtained from fennel seeds (Feoniculum vulgare Mill) and clove buds (Syzygium aromaticum) were studied by agar well dilution technique. Both essential oils (EOs) from fennel and clove exhibited pronounced and varying degrees of growth inhibition against fungal (86 to 39%) and bacterial pathogens (42 to 20%). Fennel oil depicted significant and greater fungitoxicity in case of three fungal strains Alternaria alternate (7.7, 3.8 cm) Fusarium oxysporum (5.9, 4.1 cm) and Aspergillus flavus (4.5, 3.7 cm) except two Aspergillus strains, Aspergillus acculeatus and Apergillus fumigatus where clove oil showed greater inhibition zone (5.5, 5.9 cm) (3.5, 3.7 cm) respectively. A. alternate was found to be most sensitive strain, which growth was suppressed up to 86% by fennel seeds oil. Bactericidal activity of culinary spices was evaluated against five food spoilage bacteria namely: Pseudomonas syringae, Bacillus subtilis, Escherichia coli, Staphylococcus sp., and Aeromicrobium erythreum. Fennel oil was found fairly active against bacterial strains as compared to clove oil with highest antibacterial activity against Gram positive bacteria Bacillus subtilis (3.8 cm) and least against Gram negative bacteria E. coli (2.2 cm). The summarizing results from the present investigation showed that fennel seeds oil is a relatively stronger antimicrobial agent against broad range of pathogens as compared to clove oil, except in case of certain Aspergillus strains and E. coli.Key words: Food spoilage, anti-bacterial, pathogenic fungi, clove, fennel, essential oil

Essential oil of Eucalyptus citriodora: Physio-Chemical analysis, Formulation with Hand Sanitizer Gel and Antibacterial Activity

Background: The essential oil-bearing plants are extensively being used in traditional systems of medicine due to the occurrence of the diversity of phytochemical constituents. The emerging crisis of developing resistance to conventional drugs has increased public health awareness and reliance on natural compounds as safer alternatives.Methods: The essential oil extracted from Eucalyptus citriodora (Hook.) leaves was characterized for physicochemical attributes, formulated with hand sanitizer gel, tested for organoleptic parameters, and antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis.Results: E. citriodora essential oil (EEO) had a camphorous scent, and dark yellow coloration, while exhibiting 0.60% yield (v/w, 97% pure), 0.94 density, 1.47 refractive index, 11.10 viscosity, 0.92 specific gravity, 0.0-9.98º optical rotation, 11.20 acid number, 50.60 ester number, which satisfy the standards specified by ISO (The International Organization for Standardization). The chromatographic analysis of oil identified eucalyptol as the most abundant compound (80.08%) followed by α-terpinyl acetate, isopinocarveol, and globulol as the moderately abundant compounds (4.46-4.81%), while viridiflorol and terpinen-4-ol as less abundant compounds (3.06 and 2.69%, respectively). Formulated hand sanitizer with EEO exhibited physical and microbiological properties that were comparable with the market products. It also had a pleasant scent, was compatible with the skin, was easy to apply, and is acceptable to the users.Conclusion: The current study clearly shows that EEO could be utilized as a potential ingredient in alcohol-based gel hand sanitizer formulation for giving a pleasant smell, acceptable physical appearance and microbial quality parameters.Keywords: Essential oil; Eucalyptol; Hand sanitizer; Gel Formulation; Antimicrobial effect

(4R,5R,6S,7R,8S,9R,10S,13S)-7,8β-Epoxy­momilactone-A

The title compound, C20H26O4, was extracted from Leucas Urticifolia, a wild Lamiaceae herb distributed in the Punjab, Baluchistan, Sindh and the Rajputana desert of Pakistan. The plant is utilized for various medicinal applications by the local community. The title compound is based on the pimarane–diterpene skeleton. The mol­ecule exhibits an ep­oxy ring fused to momilactone-A, leading to a penta­cyclic mol­ecular structure. The absolute configuration was assigned by comparison with the crystal structure of momilactone, but needs further verification. The crystal structure is governed by four inter­molecular hydrogen-bond inter­actions of the C—H⋯O type

Anticancer activity of ethyl-acetate fraction of Sorbaria tomentosa and compounds identification through HPLC and LC-MS analysis

Sorbaria tomentosa (Lindl.), is a graceful shrub bearing a science-based health benefits. This study aimed at assessing the anticancer potential of ethyl-acetate fractions (EtOAc) of S. tomentosa, and to identify bioactive natural compounds using HPLC and LC-MS techniques. Prior to the chromatographic analysis, four sub-fractions (SPE-1-SPE-4) were obtained from solid phase extraction (SPE) of EtOAc of the methanolic plant extract. SPE-2 fraction exhibited considerable levels of cytotoxicity (IC50: 50–75 µg/mL) than the rest of the sub-fractions with IC50 ranging in between 230 and 370 µg/mL against A-549, HepG2, and EI-138 human the cancer cell lines. SPE-2 was injected into a semi-preparative reverse HPLC-based-PDA revealing the occurrence of phenolic compounds. LC-MS analysis resulted in the identification of four bioactive phenolic compounds namely trans-p-sinapoyl-β-D-glucopyranoside (1), dunnianoside F (2), linoside A (3), and asplenetin (4) in SPE-2. In conclusion, the isolated compounds from the SPE-2 sub-fraction are the potential source of marked phenolic compounds that might be a promising option as anticancer agents in both cancer prevention and treatment