Presence Of Secondary Metabolites Research Articles

The Significance of Xylem Structure and Its Chemical Components in Certain Olive Tree Genotypes with Tolerance to Xylella fastidiosa Infection.

Olive quick decline syndrome (OQDS) is a devastating plant disease caused by the bacterium Xylella fastidiosa (Xf). Exploratory missions in the Salento area led to the identification of putatively Xf-resistant olive trees (putatively resistant plants, PRPs) which were pauci-symptomatic or asymptomatic infected plants belonging to different genetic clusters in orchards severely affected by OQDS. To investigate the defense strategies employed by these PRPs to contrast Xf infection, the PRPs were analyzed for the anatomy and histology of xylem vessels, patterns of Xf distribution in host tissues (by the fluorescent in situ hybridization technique-FISH) and the presence of secondary metabolites in stems. The xylem vessels of the PRPs have an average diameter significantly lower than that of susceptible plants for each annual tree ring studied. The histochemical staining of xylem vessels highlighted an increase in the lignin in the parenchyma cells of the medullary rays of the wood. The 3D images obtained from FISH-LSM (laser scanning microscope) revealed that, in the PRPs, Xf cells mostly appeared as individual cells or as small aggregates; in addition, these bacterial cells looked to be incorporated in the autofluorescence signal of gels and phenolic compounds regardless of hosts' genotypes. In fact, the metabolomic data from asymptomatic PRP stems showed a significant increase in compounds like salicylic acid, known as a signal molecule which mediates host responses upon pathogen infection, and luteolin, a naturally derived flavonoid compound with antibacterial properties and with well-known anti-biofilm effects. Findings indicate that the xylem vessel geometry together with structural and chemical defenses are among the mechanisms operating to control Xf infection and may represent a common resistance trait among different olive genotypes.

Unleashing Bacillus species as versatile antagonists: Harnessing the biocontrol potentials of the plant growth-promoting rhizobacteria to combat Macrophomina phaseolina infection in Gloriosa superba

Charcoal rot caused by Macrophomina phaseolina is one of the most devastating diseases that cause severe yield loss in Gloriosa superba cultivation. Plant growth-promoting rhizobacteria (PGPR) are extensively harnessed as biocontrol agents due to their effectiveness in combating a wide array of plant pathogens through a multifaceted approach. The present study delved into the mechanisms underlying its ability to inhibit root rot pathogen and its capacity to promote plant growth in G. superba, commonly known as glory lily. PGPR isolated from the rhizosphere of glory lily were subjected to in vitro assessments using the dual plate technique. The isolated Bacillus subtilis BGS-10 and B. velezensis BGS-21 showed higher mycelial inhibition (61%) against M. phaseolina. These strains also promote plant growth by producing indole-3-acetic acid, siderophore, ammonia, amylase, cellulase, pectinase, xylanase, and lipase chemicals. Genome screening of BGS-10 and BGS-21 revealed the presence of antimicrobial peptide genes such as Iturin (ituD gene), surfactin (srfA and sfp genes) along with the mycolytic enzyme β-1,3-glucanase. Further, the presence of secondary metabolites in the bacterial secretome was identified through gas chromatography-mass spectrometry (GC/MS) analysis. Notably, pyrrolo[1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl), 9 H-pyrido[3,4-b] indole and L-leucyl-D-leucine exhibited the highest docking score against enzymes responsible for pathogen growth and plant cell wall degradation. Under glasshouse conditions, tuber treatment and soil application of talc-based formulation of B. subtilis BGS-10 and B. velezensis BGS-21 suppress the root rot incidence with a minimal disease incidence of 27.78% over untreated control. Concurrently, there was a notable induction of defense-related enzymes, including peroxidase (PO), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL), in glory lily. Therefore, it can be concluded that plant growth-promoting Bacillus strains play a significant role in fortifying the plant's defense mechanisms against the root rot pathogen.

Phytochemical screening and antibacterial activity testing of n-hexane extract from Barringtonia asiatica seeds

Barringtonia asiatica, a marine plant belonging to the Lecythidaceae family, exhibits bioactivity in all parts of the plant. In the Simeulue region, the seeds of this plant are used for fish trapping. The polar extracts of B. asiatica seeds has shown antibacterial activity, but the non-polar extracts has not been studied yet. Therefore, this study aimed to determine the secondary metabolites of B. asiatica using a non-polar solvent (n-hexane) and evaluate its activity against Gram-positive and Gram-negative bacteria. The extraction method employed using soxhlet extraction, and the antibacterial activity was determined using the Kirby-Bauer method. The presence of secondary metabolites in the B. asiatica seed extract was assessed using phytochemical tests, and its chemical composition was analyzed using Gas Chromatography Mass Spectrophotometry (GC-MS). The yield of n-hexane extract from B. asiatica seeds was 1.7%, and the phytochemical analysis revealed that the B. asiatica seed’s n-hexane extract contains only terpenoids compounds. The B. asistica seed’s n-hexane extract at concentration of 10% (w/v) showed the highest zone of inhibition against Staphylococcus aureus (9.3 mm) followed by Escherichia coli (9,9 mm). The GC-MS analysis showed that B. asiatica seed’s n-hexane extract contains Guaiene, Guaiene, Ledene, 9,12-Octadecadienoic acid, and Ethyl linoleate. Based on these findings, it can be concluded that B. asiatica seed's n-hexane extract exhibited antibacterial activity against S. aureus and E. coli.

Unveiling the Potential of Secang (Caesalpinia sappan L.) as a Novel Tanning Agent: A Promising Alternative for the Leather Industry

The exploration of vegetable tanning's natural resources is fascinating as an alternative to basic chromium sulfate for its natural abundance and considerable environmental impact. In this work, an attempt has been made to extract vegetable tannin from Caesalpinia sappan L. bark using water as a solvent with different levels of temperatures and incubation times. The highest yield efficiency was observed at 80 °C for 4 hours. The presence of tannin content and polyphenolic compounds were screened by the phytochemical analysis using Iron (III) chloride (FeCl3), sodium hydroxide (NaOH), and ensured by the thin layer chromatography (TLC), and the Fourier transform infrared (FTIR). The extracts were then determined by percentage of extract yield, phytochemical, tannin type, moisture, total solids, and tannin characteristics. The findings indicate that the extract of Secang contains 4.98±0.28% total moisture, 95.02 ± 0.28% total solids, and 72.12 ± 2.81% total soluble solids, 52.28 ± 1.79% tannins, and 19.84 ± 1.41% non-tannin. Moreover, Fourier transform infrared (FTIR) analysis revealed a clear functional group within Caesalpinia sappan L., as evidenced by the type of tannin that is condensed. The TLC assay exhibited a considerable intensity under UV lights. It included several shades of light blue and blue, which could indicate the presence of secondary metabolites and tannin. Compared to mimosa, as the commercial standard for tanning agents in the leather industry, Caesalpinia sappan L. presents promise as an eco-friendly substitute for basic chromium sulfate and a new alternative source of vegetable tannin for the leather industry.

Phytochemical screening and antimicrobial activity of Polygala sadebeckiana Gürke extracts on bacterial isolates from Wound samples of patients with “Shimetere”

BackgroundModern medicine is not the choice of patients with “shimetere” in the Gurage community owing to their perception of ‘parenteral medication use severely aggravates the disease’. For this reason, the root part of Polygala sadebeckiana Gürke is commonly utilized as traditional medicine in the management of the disease. The aim of this study was to evaluate the antimicrobial activity of Polygala sadebeckiana Gürke extract on bacterial isolates from wound samples of patients with “Shimetere”.MethodsThe agar well diffusion method was used to evaluate antibacterial activity, and the agar dilution method was utilized to determine minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MICs). The crude extract was tested against isolated bacteria at concentrations of 25, 50, 75 and 100 mg/mL in triplicate (3x). The positive controls were azithromycin (15 µg) and cloxacillin disk (5 µg), and the negative control was dimethylsulfoxide (5%). The group mean comparisons were made using one-way ANOVA at a significance level of p < 0.05, and the results are presented as the mean ± standard deviation. The presence of secondary metabolites from crude extract was checked by standard testing procedures.ResultsS. aureus and S. pyrogen were the two identified bacteria from 9 (60%) and 3 (20%) wound samples, respectively. All identified bacterial strains were susceptible to the reference antibiotics. Tannins and saponins were the most abundant secondary metabolites found in the crude extracts. The average inhibition zones of the plant extracts with 100, 75, 50 and 25 mg/mL concentrations were 27, 20.33, 15.25, and 11.96 mm (p < 0.000) for S. aureus and 30.02, 24.50, 19.07, and 15.77 mm (p < 0.000) for S. pyrogen bacteria, respectively. The MIC and MBC of the crude extract were 1.67 and 10 mg/mL for S. aureus and 0.98 and 4 mg/mL for S. pyrogen.ConclusionPolygala sadebeckiana Gürke contained significant tannins and saponins as secondary metabolites and had antibacterial activities against isolated bacteria (S. aureus and S. pyrogen) from “Shimetere”. The potential mechanism of antibacterial action of the plant extract was cell wall synthesis inhibition.

In vitro Antibacterial Activity of Seribu kuman Leaf (Rhinacanthus nasutus (l.) Kurz) Extracts Against Staphylococcus aureus and Pseudomonas aeruginosa

Seribu Kuman leaves (Rhinacanthus nasutus (L.) Kurz) are the herb most commonly used in traditional medicine to treat various diseases. The presence of secondary metabolites, including flavonoids, alkaloids, and phenolics, has led to its known antibacterial activity. This study aims to verify the antibacterial activity of Seribu Kuman leaf extract against Staphylococcus aureus and Pseudomonas aeruginosa. This study involved experimental design using the Kirby-Bauer method, inoculating Mueller-Hilton Agar (MHA) test media containing S. aureus and P. aeroginosa bacteria with Seribu Kuman leaves ethanol extracts at concentrations of 15%, 30%, and 60%. Penicillin and ciprofloxacin were used as positive controls, whereas sterile aquabidest was used as a negative control for the study. The findings of this study showed that Seribu Kuman (R. nasutus) ethanol extract, at a concentration of 60%, presented the most significant inhibition zone against S. aureus, measuring 13.6 mm. In contrast, no inhibition zone was observed for P. aeroginosa. It can be concluded that Seribu Kuman (R. nasutus) ethanol extract can inhibit the growth of S. aureus but not P. aeruginosa. So, Seribu Kuman leaves (R. nasutus) ethanol extract could be an alternative for treating infections caused by S. aureus.

A Role for Secondary Metabolites in Desiccation Tolerance in Lichens

In lichens, secondary metabolites have been shown to protect against biotic stresses such as pathogen attacks and grazing, and abiotic stresses such as ultraviolet (UV) and high photosynthetically active radiation (PAR). Lichen secondary metabolites are known to have strong antioxidant activity, and while theoretically they may have roles in tolerance to other abiotic stresses, these roles remain largely unclear. Here, we used the acetone rinsing method to harmlessly remove most of the secondary metabolites from the thalli of six lichen species. This enabled us to compare the effects of desiccation on thalli with and without the presence of secondary metabolites. Results showed that in general, the presence of lichen substances reduces the effects of desiccation stress. For all species, substances significantly improved the photosystem two (PSII) activity of the photobiont during either desiccation or rehydration. In the mycobiont, in four of the six species, the presence of substances reduced membrane damage, which was assessed by measuring ion leakage during rehydration following desiccation. However, in one species, secondary metabolites had no effect, while in another the presence of substances increased membrane damage. Nevertheless, it seems clear that in addition to their more established roles in protecting lichens against pathogen attacks and grazing, lichen substances can also play a role in aiding desiccation tolerance.

Biological activities and phytochemical prospection of plant extracts of Myrsine Umbellata mart

Myrsine umbellata is a Brazilian native species from the Primulaceae family, popularly known as “Capororocão.” Considering that plants have been used to treat various illnesses, explaining interest in research with Brazilian native species in the search for plant bioactives with biological potential that can act on the control of pathogenic microorganisms. Thus, the present study aimed to identify the phytochemical compounds of the leaves of the native species M. umbellata, as well as to evaluate the antimicrobial potential of Methanolic (ME), Acetonic (AE), Ethanolic (EE), and Hexanic (HE) plant extracts against bacteria of clinical and veterinary importance. The presence of secondary metabolites was analyzed by observing color changes or precipitate formation reactions, and the antimicrobial activity was determined by broth microdilution methodology. Through phytochemical prospecting, the presence of nine classes of metabolites was detected: tannins, saponins, free steroids, alkaloids, anthocyanins, anthocyanidins, flavones, flavonoids, and flavanonols. The extracts exhibited antimicrobial activity against all tested strains. ME showed the best MIC results for the standard strains. The most susceptible strains were gram-positive: Staphylococcus epidermidis and Enterococcus faecalis and gram-negative: Salmonella enterica Typhimurium, Pseudomonas aeruginosa, Proteus mirabilis besides the yeast Candida albicans. The results indicate that the species M. umbellata shows the potential for isolating natural bioactives and the potential development of products such as non-synthetic antimicrobials.

GCMS characterization and biological potential of the seeds and aerial part of Galium tricorne Stokes.

Natural products have long been proven very effective against various challenging diseases including cancer and bacterial infections. Galium tricorne is one of the important source of natural products, which has not been explored till date in spite of its profound ethnomedicinal prominence. The current study has been designed to explore the biological potential of G. tricorne and to extract and isolate chemical constituents from its aerial part and seeds respectively along with identification of their chemical constituents. Phytochemical screening was performed to figure out the presence of secondary metabolite in G. tricorne. Crude Methanolic extract (Gt.Crd), which was obtained from the aerial part while the fatty acids were extracted from the seeds, which were later on analyzed by GCMS. Similarly, Well Diffusion and MTT method were used for antibacterial activity and cancer cell line assay respectively. To evaluate the cytotoxic potential, brine shrimps were used. Likewise, in Gas Chromatography-Mass Spectroscopy (GC-MS) analysis a total number of 23 compounds were identified in Gt.Crd extract out of which 7 compounds were sorted out to have some sort of toxicity profile. In the same fashion, 5 fatty acids were identified in the seeds of G. tricorne. Moreover, among the fractions, chloroform fraction (Gt.Chf) exhibited greater zone of inhibition (ZOI) 20.37 mm followed by Gt.Crd 18.40 mm against S. aureus and S. pyogenes respectively. In cytotoxicity Gt.Chf was more active followed by ethyl acetate fraction (Gt.Eta) by exhibiting 88.32±0.62% (LC50=60 µg/mL) and 73.95±2.25% (LC50=80 µg/mL) respectively at 1000 µg/mL concentration of the tested sample. Gt.Chf exhibited greater cell line inhibitory activity (IC50=61 µg/mL) against HeLa cell line. Similarly, Gt.Crd displayed IC50 values of 167.84 µg/mL and 175.46 µg/mL against HeLa and NIH/3T3 cell line respectively. Based on the literature review and screenings, it may be concluded that the aerial part and seeds of G. tricorne are the rich sources of bioactive compounds. The results of the current study also authenticate the scientific background for the ethnomedicinal uses of G. tricorne.

Phytochemical Screening and Some Antibacterial Activities of Clerodendrum capitatum Leaves Extract

Plant were used for medicinal purposes since ancient times for treatment of diverse ailments. Clerodendrum capitatum has been used in the treatment of tuberculosis, fever, obesity, diabetes mellitus, diarrhoea, asthma, etc. In this study, C. capitatum leaves were extracted using standard procedures and then subjected to phytochemical screening, thin layer chromatography (TLC), and column chromatography. The single spot isolated compound (I1) obtained from the column was subjected to antimicrobial analysis, bioautography, Fourie Transform Infrared (FT-IR) analysis. The phytochemical screening indicates the presence of secondary metabolite like alkaloid and terpenoid. The n-hexane extract TLC show 8 spots with different Retention factors (Rf) value, then after column was done, compound with RF value 0.35 was isolated from the column chromatography. Antimicrobial test result showed that the Isolate was active against Salmonella  typhi, Bacillus megaterium, Staphylococcus epidermidis, Klebsiella spp, Escherichia coli, Pseudomonas aeruginosa, Proteus spp, Shigella spp, Bacillus subtilis and Staphylococcus aureus (with zones of inhibition range 7mm-17mm), highest activity was recorded against Staphylococcus epidermidis, and least activity against Bacillus megaterium both at concentration of 100mg/L. The bioautography also show zone of inhibition with white coloured visibility. The FT-IR analysis revealed that the isolates contain ketone functional group (RCOR) group. The presence of the secondary metabolite like alkaloids and terpenes in the crude extract and Ketone functional group in the isolate suggest the reasons for the antibacterial activity of the isolated compound.

Phenology and environment in the presence of secondary metabolites in Psidium guajava L.

Phenology and environment in the presence of secondary metabolites in Psidium guajava L.

Green synthesis of ZnONps using Horse gram seed aqueous extract and its in vitro evaluation on antioxidant, antidiabetic, anticancer and DNA binding potential

The goal of this study was to access the green production of zinc oxide nanoparticles (G-ZnO NPs) using aqueous extract of horse gram seeds (Macrotyloma Uniflorum). The precursor to the extract ratio (2.5:1) and pH value (8.5), along with the zinc nitrate concentration (0.5 M), had an impact on the particle size and the green synthesized ZnO nanoparticles. UV Spectroscopy inspection revealed formation of G-ZnO NPs with absorption at 320 nm which is the characteristic absorption of G-ZnO NPs. FTIR, XRD, SEM, EDX and TEM were used to characterize the green synthesized ZnO NPs. The findings demonstrated that the presence of secondary metabolites in the seed extractstabilize and contribute in the production of G-ZnO NPs. A dose-dependent increase in antibacterial activity was seen in evaluation of these NPs against Klebsiella, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa. The antioxidant activity and antidiabetic activity for G-ZnO NPs was also noted to be concentration dependent. The synthesized nanoparticles are found to interact with CT-DNA to produce a hypochromic shift. Further the studies on the G-ZnONPs in MCF-7 cells using the MTT test demonstrated greater cellular inhibition. The results validate that the green synthesized ZnO-NPs from horse gram seed possess good biological activities and can be an excellent biologically derived potential material which could be used in the drug discovery from natural products.

Facile biosynthesis of Ag–ZnO nanocomposites using Launaea cornuta leaf extract and their antimicrobial activity

The quest to synthesize safe, non-hazardous Ag–ZnO nanoomposites (NCs) with improved physical and chemical properties has necessitated green synthesis approaches. In this research, Launaea cornuta leaf extract was proposed for the green synthesis of Ag–ZnO NCs, wherein the leaf extract was used as a reducing and capping agent. The antibacterial activity of the prepared nanoomposites was investigated against Escherichia coli and Staphylococcus aureus through the disc diffusion method. The influence of the synthesis temperature, pH, and precursor concentration on the synthesis of the Ag–ZnO NCs and antimicrobial efficacy were investigated. The nanoparticles were characterized by ATR-FTIR, XRD, UV–Vis, FESEM, and TEM. The FTIR results indicated the presence of secondary metabolites in Launaea cornuta which assisted the green synthesis of the nanoparticles. The XRD results confirmed the successful synthesis of crystalline Ag–ZnO NCs with an average particle size of 21.51 nm. The SEM and TEM images indicated the synthesized nanoparticles to be spherical in shape. The optimum synthesis conditions for Ag–ZnO NCs were at 70 °C, pH of 7, and 8% silver. Antibacterial activity results show Ag–ZnO NCs to have higher microbial inhibition on E. coli than on S. aureus with the zones of inhibition of 21 ± 1.08 and 19.67 ± 0.47 mm, respectively. Therefore, the results suggest that Launaea cornuta leaf extract can be used for the synthesis of Ag–ZnO NCs.

A Simplified, Efficient and Rapid DNA Extraction Protocol from Rice Grains and Leaf

DNA extraction is very complicated with different plant species because the presence of secondary metabolites that hinder with DNA isolation processes and application like DNA restriction, Gene amplification, as well as gene cloning. A simple method for preparation of rice genomic DNA was developed. The current study expressed comparatively rapid, cost-effective, less time consuming, methods for DNA extraction from seed, young leaves and old leaves of rice genotypes without using liquid nitrogen, phenol, and β–mercaptoethanol in extraction buffer. Using this method, high quality and quantity of genomic DNA was get from 0.5 g of rice seed, young leaves and 75 days old leavesand extracted total nucleic acids (genomic DNA) were amplified by employing single sequence repeats (SSR) or microsatellite markers, which produced reproducible results.This protocol resolves the problems of DNA degradation, contamination, and low yield due to binding and/or coprecipitation with starches and polysaccharides.

A study on phytochemical profiling of Avicennia marina mangrove leaves collected from Indian Sundarbans

Mangroves are the most diverse and productive ecosystem that is enriched with various classes of phytochemicals having potential medicinal applications. Here we have studied the bioactive potential and the presence of secondary metabolites in Avicennia marina, one of the dominant species in the Indian Sundarbans mangrove habitat. The bioactive potential study of A. marina was carried out in terms of the determination of total phenolic content, total flavonoid content and reactive oxygen species scavenging potential. The methanolic and ethyl acetate extracts were subjected to Fourier transform infrared spectroscopy (FTIR) for functional group identification. Further, detailed phytochemical profiling has been carried out by liquid chromatography-mass spectrometry (LC-MS). The Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) values for the methanolic extract of A. marina leaves were 148.0 mg GAE g−1 dry extract and 251.9 mg CE g−1 dry extract which was higher than ethyl acetate extracts. The free radical scavenging potential showed that methanolic extract of A. marina leaves can scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical up to 96.0 % and ethyl acetate extract can scavenge up to 73.7 % at 250 µg mL−1. LC-MS metabolic profile revealed the presence of different classes of secondary metabolites like fatty acids, flavonoids, plant hormones, etc., in methanolic extract. The presence of different classes of phytochemicals in the methanolic extract proves its potential as a source of plant-derived medicinal compounds.

Plant secondary metabolite has dose‐dependent effects on bumblebees

The presence of secondary metabolites in flower nectar can mediate interactions between plants, pollinators, herbivores, and microbes. Milkweeds range in concentrations of cardenolides in flower nectar from ~ 1 to 100 ng μl–1. Using three different behavioral assays with bumblebees Bombus impatiens, we examined the impacts of the commercially available cardenolide ouabain at the range of concentrations at which cardenolides naturally occur in milkweeds. We show that after four days of exposure bees in consumption assays drank more of a nectar solution with a low ouabain concentration of 10 ng μl–1 than the control sucrose nectar, and over the course of the experiment bees consumed less of the 100 ng μl–1 ouabain solution than the control. Bee activity levels in Petri dish arena assays were not impacted by ouabain consumption, even at the highest concentrations; however, in free‐flying choice assays, bees preferentially visited artificial flowers containing 10 ng μl–1 ouabain more than flowers with sucrose control, or flowers with 100 ng μl–1 of ouabain. We therefore conclude that cardenolides may provide plants advantages to pollination at the low end of the naturally occurring range of concentrations for cardenolides, but may be costly to plants at the high end of the range. This research highlights that secondary metabolites in nectar may be under selection to be maintained at low concentrations, and species with high concentrations of secondary metabolites may be under conflicting selection pressures to maintain high circulating levels to deter herbivores at the cost of reduced pollination.

Phytochemical screening and antimicrobial activities of almonds extracts from kernel of two mango (Mangifera indica L.) varieties grown in Korhogo (North of Ivory Coast)

Mango (Mangifera indica L.) is a fruit marketed worldwide. It is a third fruit exported by Côte d’Ivoire with 10000-15000 tons for annual production among 150000 tons. The by-products of mango such as kernel almonds are not pratically valued. Therefore, this work aims to determine phytochemical compound and evaluate antimicrobial activity of extracts from kernel almonds of mango varieties Kent and Keitt. Aqueous and hydroethanolic extracts were prepared with almonds flours of Kent (EtaqKE and EethKE) and Keitt (EtaqKI and EethKI) varieties. Phytochemical screening of the four extracts was performed by tube tests and thin layer chromatography. Antimicrobial activity of these extracts was evaluated in vitro with agar broth dilution method against three bacteria (Escheichia coli, Staphylococcus aureus and Pseudomans aeruginosa) and three fungi (Candida albicans, Trichophyton rubrum and Trichophyton mentagrophytes) involved in skin infections. Phytochemical screening revealed presence of polyphenols, sterols, terpenes, flavonoids, anthraquinones and saponins in all the four almonds extracts. Antimicrobial tests showed that, extracts EethKE and EethKI are the most active with MIC and MBC ranging respectively from 0.39 to 12.5 mg/mL and 12.5 to 50 mg/mL for bacteria. The extract EtaqKI is more active on bacteria and has a bactericidal action on P. aeruginosa and E. coli strains with ratio CMB/CMI of 4. The four almonds extracts have any activity on fungi strains tested. The presence of secondary metabolites and antibacterial activities of extracts of almond from kernels of mango Kent and Keitt varieties demonstrate that these extracts could have therapeutic and cosmetic applications.

Reserve mobilization and secondary metabolites during seed germination and seedling establishment of the tree Erythrina velutina (Fabaceae)

Introduction: The lack of knowledge on seed germination and seedling establishment is a main constraint for the restoration of degraded areas, including the tropical dry forest known as Caatinga. Objective: To assess reserve and secondary metabolite mobilization during seed germination and seedling establishment in Erythina velutina. Methods: We scarified, disinfected, imbibed, sown between towel paper, and incubated seeds under controlled conditions. We hydroponically cultivated seedlings in a greenhouse. We harvested cotyledons at seed imbibition, radicle protrusion, hypocotyl emergence, apical hook formation and expansion of cordiform leaves, first trifoliate leaf, and second trifoliate leaf. Results: Seeds contained approximately 20 % starch, 14.5 storage proteins, 11.6 neutral lipids, and 5.7 % non-reducing sugars on a dry weight basis. Soluble sugars were mainly consumed from hypocotyl emergence to apical hook formation, while major reserves were mobilized from apical hook formation to expansion of first trifoliate leaf. Enzymatic activity increased from mid to late seedling establishment, causing the mobilization of starch, oils, and proteins. Terpenoid-derivatives, flavonoids, phenolic acids, and alkaloids were detected. Flavonoids and phenolic acids were present at almost all stages and terpenoid-derivatives disappeared at expansion of cordiform leaves. Conclusion: Soluble sugars support early seedling growth, while starch, oils and proteins are simultaneously mobilized from mid to late establishment by amylases, lipases, and acid proteases. The cotyledons contain secondary metabolites, which may act in seedling defense. High content of reserves and presence of secondary metabolites in the cotyledons could enable E. velutina seedlings endure stress, validating their use in the restoration of degraded areas.

PENENTUAN KANDUNGAN ANTIOKSIDAN DAN FENOLIK TOTAL DARI EKSTRAK TUMBUHAN SEBAGAI BIOREDUKTOR DALAM PEMBENTUKAN NANOPARTIKEL PERAK

The formation of metal nanoparticles (silver, gold, platinum) by biological methods (green synthesis) has advantages over chemical and physical methods because it is easier, faster, simpler, and environmentally friendly. One of the substances used in this method is plant extracts. The presence of secondary metabolites that act as antioxidants such as phenolics and flavonoids play roles in the formation of silver nanoparticles. In this study, phytochemical screening was carried out from several herbal plants as bioreductors in the formation of silver nanoparticles, such as Phyllanthus buxifolius, Pachira aquatica, Peperomia pellucida, Ageratum conyzoides, and Piper crocatum leaf extracts. The total antioxidant content was determined using the modified phenanthroline method, and the total phenolic content determined using the Folin-Ciocalteu method. The formation of silver nanoparticles was carried out by mixing silver nitrate solution with each plant extract. Colloidal silver nanoparticles formed were then measured for their absorption spectra. The results of the antioxidant content of the five consecutive samples were 26,90 ± 0,19; 26,09 ± 0,14; 18,25 ± 0,02; 42,76 ± 0,14; dan 30,94 ± 0,14 mg AA/g, while the total phenolic contents were 48,44 ± 0,45; 21,08 ± 0,92; 17,42 ± 0,27; 57,71 ± 0,47; dan 49,83 ± 0,60 mg GA/g. Silver nanoparticles mediated by Ageratum conyzoides leaf extracts provided the highest absorbance value compared to other plants. The antioxidants and phenolic contained in the extract acts as reducing agent from silver ions into silver nanoparticles.

Sustainable Approaches for Biodiversity and Bioprospecting of Citrus

Citrus, belonging to the Rutaceae family, is a commercial fruit worldwide, and it is mainly recognized for its nutritional, anti-oxidant, and significant medicinal properties. Citruses are a group of multifaceted fruit crops with a rich traditional knowledge, deeply rooted in ethnic culture, and the fruits have been considered to be health-protecting and health-promoting food supplements since ancient times. The presence of secondary metabolites and their bioactivities has led to the development of new alternative drugs in recent years. Diverse secondary metabolites such as flavonoids, alkaloids, carotenoids, phenolic acids, and essential oils and their high bioactive properties have imparted great value to human health based on their anti-oxidative, anti-inflammatory, anti-cancer, cardiovascular protective, and neuroprotective effects. The indigenous Citrus species of India—mainly Northeast India—have distinctive and valuable genetic traits, such as resistance to biotic and abiotic stress, distinctive aroma, flavor, etc. Hence, these species are considered to be repertoires of valuable genes for molecular breeding aimed at quality improvement. There is a need for awareness and understanding among the citrus-producing countries of the exploitation of biodiversity and the conservation of Citrus for sustainable development and bioprospecting. The current review presents a holistic view of Citrus biodiversity from a global perspective, including phytochemical constituents and health benefits. Advanced biotechnological and genomic approaches for Citrus trait improvement have also been discussed to highlight their relevance in Citrus improvement.