Natural Products Journal, The - Volume 8, Issue 4, 2018

Ophiorrhiza is a genus of flowering plants with about 400 species. Phytochemical studies spanning last four decades resulted in the isolation of nearly 100 secondary metabolites, mostly alkaloids and anthraquinones, from various Ophiorrhiza species. This mini review summarizes the phytochemistry, camptothecin (CPT) screening, tissue culture-based CPT source enhancement and biological activities of the genus Ophiorrhiza. The major secondary metabolites isolated from genus Ophiorrhiza are alkaloids (49), anthraquinones (20), triterpenoids (8), diterpenes (1), sesquiterpenes (3), monoterpenes (1), steroids (6), flavonoids (2), coumarins (1), iridoids (6) and phenolic acids (2). Primary metabolites such as xanthophylls (1), pheophytins (2) and fatty acids (3) were also reported from some Ophiorrhiza species. CPT, owing to its anticancer applications, is the prominent biologically active entity found in various Ophiorrhiza species. Studies also reported the screening for elite Ophiorrhiza species/varieties with high CPT contents. Ophiorrhiza mungos and Ophiorrhiza mungos var. angustifolia showed highest CPT contents, whereas some Ophiorrhiza species/varieties showed zero or non-detectable levels of CPT. Ophiorrhiza species, mainly Ophiorrhiza pumila, were regenerated through tissue culture systems, and enhancement of their CPT contents was attempted by various groups. Most Ophiorrhiza species are still not subjected to phytochemical investigations, and these plants could provide more industrially important molecules and drug precursors.

Iridoids are secondary metabolites produced by plants and some animals as a defense mechanism against animals and insects. These are cyclopenta[c]pyrane containing monoterpenoids presenting various pharmacological effects and have been used traditionally in Ayurveda and folk medicine. Another interesting property of these chemical compounds is the production of colorants on reacting with amino acids or amine containing reactants. They produce water soluble dyes among which genipin producing blue dyes are widely studied and also used commercially. This article reviews the potential of various iridoids to produce colorants, their presumed mechanism of reaction, potential application efficiency and use of Computer aided drug design (CADD) studies for further research with regards to dye interaction with fabric or receptor when administered internally.

Aspergillus is a genus of ubiquitous fungi that are therapeutically important because the genus produces a wide range of structurally diverse secondary metabolites that are of highly considerable interest to both scientific research community and pharmaceutical industry. Genome sequencing results have indicated that chemical diversity of secondary metabolites is much larger in each species than previously thought. This review summarizes a total of 315 new secondary metabolites of Aspergillus reported from 2015 to 2017 and demonstrates the therapeutical potential of this genus by introducing their unique chemical structures and excellent bioactivities from this genus.

Background: Cyanobacteria are rich source of secondary metabolites being studied for their potential pharmaceutical applications. Objective: We studied methanolic extracts of two cyanobacteria- Nostoc muscorum NCCU-442 and Calothrix brevissima NCCU-65 for their bioactivities. Method: The phenolic content was estimated by Follin-Ciocalteu method. FRAP assay, DPPH, ABTS and SOR scavenging assays were performed to evaluate the antioxidant activity of extracts. Antimicrobial effect was studied against Staphylococcus aureus, Escherichia coli and Candida albicans by agar well diffusion assay. MTT assay was performed on cancerous HepG2 cells and Noncancerous HEK-293 cell lines to determine the anti-proliferative activity. Apoptosis was studied through DNA fragmentation assay and fluorescent microscopy. The composition of the test extracts was determined using Gas Chromatography Mass Spectroscopy (GC-MS). Results: Methanolic extract of N. muscorum NCCU-442 showed slightly higher phenolic content (55.67±0.85 mg GAE/g) than the extract of C. brevissima NCCU-65 (55.38±2.28 mg GAE/g). N. muscorum extract was observed to be the best for scavenging DPPH, ABTS radical and superoxide radicals, whereas, C. brevissima extract was better for FRAP assay. Both the extracts showed promising antimicrobial activities against given microbes. As compared to N. muscorum extract, C. brevissima extract was found to be more effective against HepG2 cell lines with IC50 value = 210.5 μg/ml. At IC50 values the extracts showed evident morphological characteristics of apoptosis. Various probable bioactive constituents were identified in the GC-MS analysis. Conclusion: The test extracts revealed that the given cyanobacterial strains have promising bioactive potential and could be developed in future as the pharmaceutical sources.

Background: Myrtle (Myrtus communis L.) an industrial medicinal plant which belongs to Myrtaceae family with various pharmacological, cosmetic and food applications. Objective: In the current study, variability in leaves Essential Oil (EO) composition of dark blue and white fruited morphs of myrtle populations collected from the same site in the south of Iran, was investigated. Method: The yield of the EO of myrtle morph populations ranged from 0.32% in Zanjiran White (ZFW) to 1.13% in Atashkedeh White (AFW) based on dry weight. According to GC-MS analysis, the chemical composition of myrtle EOs recognized classifying 47 compounds. Result: The major compounds were α-pinene (37.9-70.40%), 1,8-cineole (6.72-28.69%), linalool (0.11- 17.9%), and geraniol (t-6.42%). The most of the recognized compounds showed high chemical difference among myrtle populations. The dark blue morph belonging to Zanjiran dark Blue (ZFB) have the highest amount of α-pinene (70.40%). For 1,8-cineol the highest amount belonged to white morph ZFW (28.69%) and the lowest value belonged to dark blue morph ZFB (6.72%), respectively. Linalool as the same of 1,8-cineol showed a high chemical difference among the myrtle morphs. For linalool, the lowest and highest amounts were obtained in ZFW (0.11%) and Khergheh dark Blue (KFB) about 17.9%, respectively, while geraniol ranged from trace amount in ZFB to 6.42% in AFW populations. Conclusion: Limonene has not shown chemical difference among the myrtle morphs. The results of this investigation indicated that these Myrtus morphs could be a good genetic resource for the high percentage of α-pinene, 1, 8-cineole and linalool as valuable compounds.

Background: In the last decades, consumers have become more health conscious and their demand for foods without synthetic preservatives has increased. The use of edible films as carriers of natural antimicrobial agents provides a novel way to improve the safety and shelf-life of ready-to-eat foods. These films can reduce surface microbial populations and reduce the need for synthetic packaging materials. Edible films can be made from polysaccharides, proteins, lipids or a combination of them. Objective: For this purpose, different polymer combinations containing starch, sodium alginate, poly(vinyl-alcohol) or whey protein at different ratios were studied and the mechanical properties were determined. Methods and Results: All the films studied exhibited promising mechanical properties, with those prepared using a combination of starch, sodium alginate, PVA and whey protein at a ratio of (32/32/32/4) showing the highest Elongation at Break value. The selected film was incorporated with myrtle berries hydro-alcoholic extract as a known source of many compounds which can be used in both the food industry and for medical purposes, primarily as antimicrobial agents. The antioxidant and antimicrobial properties of the prepared film were evaluated. Our results indicate that the total phenolic content is 18.20 ± 2.56 mg GAE/g of dry weight correlated with IC50 OF 2.14 ± 0.12 mg/mL. Pronounced antibacterial activity was observed against both Staphylococcus aureus and Pseudomonas aeruginosa, whereas Escherichia coli was completely resistant. Conclusion: In conclusion, the edible film containing myrtle berries hydro-alcoholic extract could provide a new strategy to enhance microbial safety and shelf-life of foods.