New Source Of Natural Compounds Research Articles

Antibacterial Activity of Propolis Extracts from the Central Region of Romania against Neisseria gonorrhoeae.

(1) Background: Sexually transmitted infections (STIs) are among the most common infections worldwide, many of these being caused by Neisseria gonorrhoeae (NG). Increased antimicrobial NG resistance has been reported in recent decades, highlighting the need for new sources of natural compounds with valuable antimicrobial activity. This study aims to determine the effect of propolis extracts on NG strains, including antibiotic-resistant strains. (2) Methods: First void urine samples from presumed positive STI subjects were harvested. DNA was extracted, purified, and amplified via PCR for the simultaneous detection of 6 STIs. The presence of the dcmH, gyrA, and parC genes was checked in the DNA samples from NG-positive patients. The antimicrobial activity of 5 aqueous propolis extracts from central Romania was investigated in vitro against some isolated NG strains. ANOVA tests were employed to assess differences and interactions between the inhibition zone for NG strains and propolis extracts. (3) Results: 7.07% of the patients presented NG infections, some strains being resistant or intermediate-resistant to ciprofloxacin. All propolis samples exhibited an antibacterial effect, including on resistant strains. (4) Conclusions: Statistical analysis demonstrated that the diameter of the inhibition zone was influenced both by the NG strain type and the source of the propolis extracts.

Natural PTP1B Inhibitors From Polygonum cuspidatum and Their 2-NBDG Uptake Stimulation

Ten active principles (compounds 1-10) have been isolated following protein tyrosine phosphatase 1B (PTP1B) assay-guided fractionation of the methanol extract of the root of Polygonum cuspidatum. The chemical structures of the compounds were characterized mainly by nuclear magnetic resonance (NMR) spectroscopic and physicochemical data. This is the first time that 9,10-anthraquinones (compounds 5-6) have been isolated from P. cuspidatum, and this is the first record of compound 9 from the genus Polygonum. Except for compound 4, all the isolates showed potential inhibitory activity against PTP1B with half-maximal inhibitory concentration IC50 values ranging from 6.3 to 28.9 µM. Furthermore, a kinetic study indicated mixed-competitive inhibition with PTP1B for compounds 2 and 9 and noncompetitive inhibition for compounds 3 and 6. In addition, compounds 2, 3, 6, and 9 also induced the 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl) amino]-d-glucose uptake stimulation in 3T3-L1 adipocytes at concentrations of 10 and 5 µM. Taken together, the results reveal that P. cuspidatum could be a new source of natural compounds for further research and development of antidiabetic agents.

Antioxidant Activity of Dictyotales from Tropical Reefs of Brazil.

Macroalgae produce a large range of primary and secondary metabolites with ecological and economical importance. Studies on antioxidants from marine algae have increased notably, focusing on searching new sources of natural compounds for different applications, in which tropical species have been shown to have high potential, often improved by stressful environmental conditions during the tide cycle with periods of emersion and submersion. Therefore, in order to characterize the antioxidant activity and relate it to local environmental tide exposure, three species of brown marine algae, Canistrocarpus cervicornis, Dictyopteris delicatula, and Lobophora variegata from two beaches on the northeast coast of Brazil were studied. Dichloromethane:methanol (DCM:M) and aqueous extracts were tested for ferric reducing antioxidant power, 2,2-diphenyl-1-picrylhydrazyl, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) antioxidant assays and total phenolic compounds. Aqueous extracts of C. cervicornis showed up to 10 times major antioxidant activity and phenolic compounds than DCM:M extracts. Different characteristic of antioxidant activity were identified among the beaches, species, and extracts, in which aqueous extracts from C. cervicornis and L. variegata showed the most promising matrices for future prospection of natural antioxidants.

Evaluation of Chemical Composition and In-vitro Biological Activities of Three Endemic Hypericum Species from Anatolia (H. thymbrifolium, H. spectabile and H. pseudolaeve).

In the present work we carried out a phytochemical and biological investigation on three endemic Hypericum species, i.e.Hypericum thymbrifolium (H. thymbrifolium), Hypericum spectabile (H. spectabile) and Hypericum pseudolaeve (H. pseudolaeve) from Anatolia in order to discover new sources of natural compounds for the treatment of inflammatory and neurodegenerative disorders. HPLC-DAD analysis indicated that two naphthodianthrones (pseudohypericin and hypericin) together with chlorogenic acid, rutin, hyperoside, isoquercitrin, kaempferol, quercitrin, quercetin, amentoflavone, and hyperforin are the main compounds present in the methanol extracts. After chemical characterization, all extracts were in-vitro biologically assayed for antioxidant potential by lipid peroxidation inhibitory activity, DPPH, FRAP assays, and superoxide radical scavenging activity, for AChE inhibitory activity by Ellman's method, for COX inhibitory activity by using enzyme immunoassay (EIA) kit, for cytotoxic activity on HeLa and NRK-52E cell lines by MTT assay. The superoxide radical scavenging activity and lipid peroxidation inhibitory activity of H. spectabile (EC50 = 0.430 mg/mL) were more remarkable than that of H. thymbrifolium and H. pseudolaeve. The extracts showed moderate inhibitory activity on AChE (from 49.37% to 63.41%). The best inhibitory activity against COX-1 (71.77% and 77.04%, respectively) and COX-2 ( 64.14% and 72.23%, respectively) were shown by H. thymbrifolium and H. spectabile, which may be due to their richest chlorogenic acid content (0.29576% and 0.23567%, respectively). Cytotoxicity screening results showed that the extracts did not demonstrate significant cytotoxic activity. It was concluded that the most promising extract with antioxidant, anti-inflammatory, and AChE inhibition potential is H. spectabile.

Medicinal mushrooms as an attractive new source of natural compounds for future cancer therapy.

Medicinal mushrooms have been used throughout the history of mankind for treatment of various diseases including cancer. Nowadays they have been intensively studied in order to reveal the chemical nature and mechanisms of action of their biomedical capacity. Targeted treatment of cancer, non-harmful for healthy tissues, has become a desired goal in recent decades and compounds of fungal origin provide a vast reservoir of potential innovational drugs. Here, on example of four mushrooms common for use in Asian and Far Eastern folk medicine we demonstrate the complex and multilevel nature of their anticancer potential, basing upon different groups of compounds that can simultaneously target diverse biological processes relevant for cancer treatment, focusing on targeted approaches specific to malignant tissues. We show that some aspects of fungotherapy of tumors are studied relatively well, while others are still waiting to be fully unraveled. We also pay attention to the cancer types that are especially susceptible to the fungal treatments.

Phenolic profile and biological activity of Hypericum perforatum L.: Can roots be considered as a new source of natural compounds?

The aim of this study was to evaluate the phytochemical composition, antimicrobial activity and enzyme inhibitory properties of roots (RO), non-flower shoots (NFS) and flower shoots (FS) of Hypericum perforatum L. originating from the Republic of Macedonia. The identification and quantification of phenolic compounds in plant material were performed by using HPLC/DAD/ESI–MSn analysis. The antimicrobial activity on some selected species of bacteria and fungi was tested by microdilution assay. The in vitro enzyme inhibitory activity of plant extracts was measured against key enzymes involved in depression (monoamine oxidase A; MAO A), neurodegenerative disorders (acetylcholinesterase; AChE, butyrylcholinesterase; BChE and tyrosinase; TYR) and diabetes (α-amylase; α-AMYL and α-glucosidase; α-GLUC). The aerial plant samples showed biosynthetic potential for the production of phenolic acids, flavan-3-ols, flavonols, naphthodianthrones and acyl-phloroglucinols. The NFS and FS extracts exhibited strong antistaphylococcal and anticandidal activity that was related to the presence of hypericins and hyperforins. Chlorogenic acid, flavonol aglycones and glycosides, as well catechins and procyanidins from aerial parts were considered as potential AChE and TYR inhibitors. This study revealed, for the first time, the co-presence of phenolic acids, flavan-3-ols and xanthones in RO extracts. The antibacterial activity of RO extracts against Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa was related to the presence of garcinone C and γ-mangostin. The roots rich in xanthones displayed the strongest MAO A and BChE inhibition highlighting their antidepressant and neuroprotective effects. With respect to antidiabetic properties, RO extracts showed significant α-AMYL and α-GLUC inhibitory activities that were related to the contents of procyanidins and xanthones. Based on phytochemical composition and enzyme inhibitory properties, H. perforatum roots could be considered as an alternative source to obtain antidepressant, neuroprotective and antidiabetic active substances.

Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L.), J. oxycedrus (L.), J. phoenicea (L.) and Tetraclinis articulata (L.).

Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assays. Also the total phenolic and flavonoids contents of the extracts were determined spectrophotometrically. Results. All the extracts showed interesting antioxidant activities compared to the standard antioxidants (butylated hydroxytoluene (BHT), quercetin, and Trolox). The aqueous extract of Juniperus oxycedrus showed the highest antioxidant activity as measured by DPPH, TEAC, and FRAP assays with IC50 values of 17.91 ± 0.37 μg/mL, 19.80 ± 0.55 μg/mL, and 24.23 ± 0.07 μg/mL, respectively. The strong correlation observed between antioxidant capacities and their total phenolic contents indicated that phenolic compounds were a major contributor to antioxidant properties of these plants extracts. Conclusion. These results suggest that the aqueous extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus phoenicea, and Tetraclinis articulata can constitute a promising new source of natural compounds with antioxidants ability.

Anthraquinone profile, antioxidant and enzyme inhibitory effect of root extracts of eight Asphodeline taxa from Turkey: can Asphodeline roots be considered as a new source of natural compounds?

Plant-based foods have become attractive for scientists and food producers. Beneficial effects related to their consumption as dietary supplements are due to the presence of natural occurring secondary metabolites. In this context, studies on these products are important for natural and safely food ingredients evaluation. The aim of this study was to evaluate root extract of eight Asphodeline species as antioxidants, enzyme inhibitors and phytochemical content. Spectrophotometric antioxidant and enzyme inhibitory assays were performed. Total phenolic and flavonoids contents as well as the chemical free-anthraquinones profiles were determined using routinely procedure (HPLC-PDA). Data show that Asphodeline roots can be considered as a new source of natural compounds and can be used as a valuable dietary supplement. Some differences related to biological activities can be inferred to other phytochemicals that can be considered in the future for their synergic or competitive activities.

Insights into Research on Natural Products

Small, naturally derived molecules are important targets of drug research and development and are models of chemical synthesis. Such molecules accounted for over 60% of the approved drugs and pre-New Drug Application candidates from 1989 to 1995 (1). Of the top 35 ethical drug sales worldwide, drugs derived from natural products accounted for 24% in 2001 and 26% in 2002 (2). Drug research and development is gaining insights from research on natural products, a new trend that combines traditional methods with new techniques in life science. In addition to research seeking to discover natural compounds through use of isolation techniques and structural determination methods, research to identify new sources of natural compounds and classify their functions and research to modify the structures of those compounds by biosynthetic or chemical manipulation will definitely expand the field of natural product chemistry. New Sources of Medicines — Natural products were originally small molecules derived from higher plants and microorganisms on land. Plant endophytes and marine organisms represent the dominant source of compounds of pharmacological interest. Ecteinascidin 743 from Ecteinascidia turbinata has been developed into an antitumor agent while ω-conotoxin MVIIA from cone snails has been developed into an analgesic, and numerous metabolites have been evaluated in clinical trials (3). Manipulation of Secondary Metabolite Biosynthesis — Organisms biosynthesize specif ic secondary metabolites catalyzed by gene-regulated Editorial

COMPARATIVE CONTENT OF SOME BIOACTIVE COMPOUNDS IN TWO VARIETIES OF CAPSICUM ANNUUM L. SWEET PEPPER AND EVALUATION OF THEIR ANTIMICROBIAL AND MUTAGENIC ACTIVITIES

ABSTRACT In the framework of a project aimed to select some genotypes of Capsicum annum potentially exploitable for giving high-quality products, this research compared the total content of some bioactive compounds (polyphenols, flavonoids, carotenoids and ascorbic acid) and the antioxidant activity between of two cultivars of “Corno di Toro” sweet peppers, commonly named “Lampo” and “Teseo.” They were also investigated for their in vitro antimicrobial action against different bacteria and fungi, as well as for their mutagenic and antimutagenic activities. A relevant content of the active compounds was found, showing cultivar Lampo a higher content of polyphenols and a greater antioxidant potential. The antimicrobial action was different, exhibiting the compounds from variety “Lampo” a discrete activity against Bacillus cereus, Escherichia coli and Penicillium expansum, whereas extracts from “Teseo” showed inhibition against E. coli and Debaryomyces hansenii. The antimutagenic activity, assayed with Ames test by using the Salmonella typhimurium Histidine-requiring strain TA100, was significant, with a percentage of mutagenicity inhibition comparable to the negative control. The two cultivars could be of great interest as relevant polyphenols sources and for their antimicrobial and antimutagenic properties. PRACTICAL APPLICATIONS Sweet pepper (Capsicum annuum L.) is a broadly diffused plant. The information gathered from our work can contribute to a better selection of those genotypes of C. annum potentially exploitable for giving high-quality products, in terms of biochemical compounds and antioxidant activity. With the emergence of antibiotic-resistant microorganisms, it is reasonable to explore new sources of natural compounds with antibiotic activities: our study showed the possibility to use the extracts of two genotypes of a common edible plant, like sweet pepper, as harmless and economical antibacterial and antifungal compounds. In view of the fact that several human diseases, like cancer, are recognized as taking place from free radical damage, the inclusion in the diet of those genotypes of sweet pepper with noteworthy antimutagenic property could contribute in the prevention or limitation of such disease.