Metabolites Alkaloids Research Articles

Fabrication of Gd2O3 nanoparticles in hexane-water system using Myristica fragrans Houtt leaves extract and their photodegradation activity of malachite green

This study aims to fabricate the Gd2O3 nanoparticles (NPs) using Myristica fragrans Houtt leaves extract (MFE) in hexane-water phases system by high-speed stirring method. We performed a phytochemical test to qualitatively confirm that MFE contained the secondary metabolite of alkaloid, steroid and saponin as a weak base source (OH−), a stabilizing agent, and a capping agent in the Gd2O3 NPs fabrication, respectively. According to SEM image, the morphology of Gd2O3 NPs was spherical shape in agglomeration. UV-Vis DRS result shows that Gd2O3 NPs has a large bandgap which was found to be 5.1 eV. XRD characterization shows that the diffraction pattern of the formed nanoparticle was well-matched with the data source of Gd2O3. The particle size of Gd2O3 NPs was approximately 40 nm confirmed by PSA. Photocatalytic activity of Gd2O3 NPs was tested for dye degradation. In this study, malachite green was utilized as a modelling of dye. The photodegradation percentage of malachite green using Gd2O3 NPs catalyst was 75.15 % for 120 min under UV light irradiation.

1-Formyl-7-hydroxy-6,7-dihydro-5H-pyrrolizine (1-CHO-DHP)-Cysteine Conjugates: Metabolic Formation and Binding to Cellular DNA.

1-Formyl-7-hydroxy-6,7-dihydro-5H-pyrrolizine (1-CHO-DHP) is a potential proximate carcinogenic metabolite of pyrrolizidine alkaloids. In the present study, we determined that the reaction of 1-CHO-DHP with cysteine generated four identified products. By mass and 1H NMR spectral analyses, these products are cysteinyl-[2'-S-7]-1-CHO-DHP (P2), cysteinyl-[3'-N-7]-1-CHO-DHP (P3), 7-keto-DHP (P4), and 1-cysteinylimino-DHP (P5). These four compounds were also formed from the incubation of 1-CHO-DHP in HepG2 cells. Compounds P3 and P5 were interconvertible in acetonitrile and water. Incubation of P2 in HepG2 cells generated the four DHP-dG and -dA adducts that we propose to be potential common biomarkers of pyrrolizidine alkaloids exposure and pyrrolizidine alkaloids-induced liver tumor initiation. These four DHP-DNA adducts were also formed from the incubation of a mixture of P3 and P5 in HepG2 cells but not from the incubation with 7-keto-DHP. From the reaction of 1-CHO-DHP with glutathione, only trace amounts of the glutathione-1-CHO-DHP adduct were detected, with the structure unable to be characterized.

Effects of Solvent and pH on Stingless Bee Propolis in Ultrasound-Assisted Extraction

Ultrasound-assisted extraction was used to extract propolis from a dark and resinous substance harvested from a beehive of Heterotrigona itama, which is commonly known as stingless bees. The propolis extracts were prepared using ethanol and water at different pH values of 3, 6, and 9. The yield of the ethanolic extract was significantly higher than the water extract, but there were no significant differences at different pH values. The ethanolic extract was found to have a lower 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the water extract at pH values of 6 and 9. However, the acidic propolis extracts, particularly the ethanolic extract, were found to have the highest antioxidant capacity. The addition of 20% polyethylene glycol 400 in the solvent systems was unlikely to improve propolis extraction. This can be seen from the antioxidant capacity and metabolite profile of the propolis extracts. Gas chromatography–mass spectrometry (GC–MS)-based high throughput screening of the propolis extracts showed them to have small metabolites of hydrocarbons, esters, terpenes, and alkaloids, as well as high antioxidative 2,4-di-tert-butylphenol. The detection of mangostin, mangiferin, and a few flavanones in the acidic ethanolic extract by liquid chromatography tandem mass spectrometry LC–MS/MS proved its high antioxidant capacity compared to the water extract.

Karakteristik Gel Sariawan Ekstrak Daun Sirih Hitam sebagai Antimikroba dengan Variasi Konsentrasi Carbopol

Betel plant is a terna plant that can be used as an antifungal, antimicrobial and antioxidant. Black betel leaf is proven to contain secondary metabolites of alkaloids, carotenoids, phenolic compounds, flavanoids, saponins, tannins, steroids, and triterpenoids. Gel preparations are used aimed at prolonging the contact time of the preparation with the target location, extending the absorption time and increasing the therapeutic effect. This study aims to determine the characteristics of gel extract of black betel leaf. Black betel leaf extract was obtained by macerating with 70% ethanol into an oral gel preparation as an antimicrobial with carbopol concentration variations. The results of antimicrobial test showed that 5% concentration of black betel leaf extract could increase the growth of Streptoccus sanguinis with inhibition zone diameter 6.261 ± 1.425mm and Candida albicans with inhibition zone diameter 5.152 ± 0.952mm. Black betel leaf extract gel formula F3 with 1.5% carbopol concentration is the best formula that has greenish black, betel and mint flavored, and has a thick and homogeneous shape. It has a viscosity of 2.266 Pa.s, has a pH of 5.37 and spread power 4.37cm.

Cordycepamides A−E and cordyglycoside A, new alkaloidal and glycoside metabolites from the entomopathogenic fungus Cordyceps sp.

Five new alkaloidal metabolites cordycepamides A−E (1−5), and one glycoside metabolite cordyglycoside A (6), together with six known compounds (7−12) were isolated from the entomopathogenic fungus Cordyceps sp. (LB1.18060004) from unidentified insect collected in Baoshan City, Yunnan Province, People's Republic of China. The structures were characterized by NMR and HRESIMS spectroscopic analyses. Cordycepamides A and B (1 and 2) were mixtures of two isomers in 5:4 ratio by integration of 1H NMR spectra. In additional, the structure of cordycepamide A (1) was further confirmed by X-ray crystallography as a pair of enantiomers. Absolute configurations of sugar moiety of cordyglycoside A (6) was confirmed by the acid hydrolysis and subsequent HPLC analysis. The isolated metabolites were evaluated for antimicrobial, cytotoxicity, and the DPPH scavenging assay, only 4 showed modest antioxidant effects in the DPPH scavenging assay (IC50 = 51.42 ± 3.08 μM).

A Co-Culturing Approach Enables Discovery and Biosynthesis of a Bioactive Indole Alkaloid Metabolite.

Whole-genome sequence data of the genus Streptomyces have shown a far greater chemical diversity of metabolites than what have been discovered under typical laboratory fermentation conditions. In our previous natural product discovery efforts on Streptomyces sp. MA37, a bacterium isolated from the rhizosphere soil sample in Legon, Ghana, we discovered a handful of specialised metabolites from this talented strain. However, analysis of the draft genome of MA37 suggested that most of the encoded biosynthetic gene clusters (BGCs) remained cryptic or silent, and only a small fraction of BGCs for the production of specialised metabolites were expressed when cultured in our laboratory conditions. In order to induce the expression of the seemingly silent BGCs, we have carried out a co-culture experiment by growing the MA37 strain with the Gram-negative bacterium Pseudomonas sp. in a co-culture chamber that allows co-fermentation of two microorganisms with no direct contact but allows exchange of nutrients, metabolites, and other chemical cues. This co-culture approach led to the upregulation of several metabolites that were not previously observed in the monocultures of each strain. Moreover, the co-culture induced the expression of the cryptic indole alkaloid BGC in MA37 and led to the characterization of the known indolocarbazole alkaloid, BE-13793C 1. Neither bacterium produced compound 1 when cultured alone. The structure of 1 was elucidated by Nuclear Magnetic Resonance (NMR), mass spectrometry analyses and comparison of experimental with literature data. A putative biosynthetic pathway of 1 was proposed. Furthermore, BE-13793C 1 showed strong anti-proliferative activity against HT-29 (ATCC HTB-38) cells but no toxic effect to normal lung (ATCC CCL-171) cells. To the best of our knowledge, this is the first report for the activity of 1 against HT-29. No significant antimicrobial and anti-trypanosomal activities for 1 were observed. This research provides a solid foundation for the fact that a co-culture approach paves the way for increasing the chemical diversity of strain MA37. Further characterization of other upregulated metabolites in this strain is currently ongoing in our laboratory.

The potential of arabica coffee grounds nanoparticles as an active compound of pharmaceutical preparations

Arabica coffee (Coffea arabica L.) grounds are kind of solid waste produced from filtering process containing many bioactive components and good for health. Nanoparticle technology can be used to produce nanoscale particles without separating the active compounds contained the rein. The aim of this study is to determine the potential of Arabica coffee grounds nanoparticles as active compounds to be used in pharmaceutical preparations. The research procedure was begun with collect the Arabica coffee grounds which was then processed into nanoparticles using the ball milling and ultrasonication technique. The nanoparticles were characterized using some techniques, namely particle size analysis using PSA (Particle Size Analyzer), phytochemical screening, total phenolics, pH, particle morphology using SEM (Scanning Electron Microscopy) and particle structure using FT-IR (Fourier Transform Infrared Spectroscopy). The results showed that Arabica coffee grounds nanoparticles has a particle size of 396.0 nm with a polydispersity index of 0.254, solubility of 70.680% and pH 5.33, the positive Arabica coffee grounds nanoparticles containing secondary metabolites of alkaloids, saponins and phenolics with total phenolics 1246.90 μgGAE/g. Morphology of Arabica coffee grounds nanoparticles was in irregular granules form with an asymmetrical size and has active functional groups such as OH, NH, CH alkane, C≡N, C=O carboxylic acid, -C=C-, CO, and CC. It can be concluded that Arabica coffee grounds nanoparticles were potentially can be used as active compounds in various pharmaceutical preparations.

Phytochemical screening, antioxidant activity and thin-layer chromatography test of methanol extract and simplicia leaves of loquat (Eriobotrya japonica Lindl)

Loquat (Eriobotrya japonica Lindl) is a medicinal plant that can be found in the Highlands in the region of Indnesia. Loquat has been widely used as a traditional medicine material by ethnic Chinese since ancient times. The research aims to analyse the phytochemical content and antioxidant activity of methanol extracts and simplisia loquat leaves. Phytochemical screening results show that methanol extract contains a secondary metabolite of alkaloids, flavonoids and steroid/terpenoid, while the Leaves Simplisia E.japonica contains a compound of secondary metabolites of alkaloids and flavonoids. Methanol extracts and Simplisia of E.japonica leaves were tested using DPPH with a high concentration of 20, 40, 60 and 80 ppm, incubated for 15 minutes and then measured by a spectrophotometer at a wavelength of 516 nm. Methanol leaves E.japonica extract has a value of IC50 39.4 ppm very strong category, while the Leaves Simplisia E.japonica has a value of IC50 102.4 ppm of medium category. The Rf value of methanol extract with a variation in solvent comparison (6:6, 7:3, 8:2, 9:1) is 0.78, 0.69, 0.51 and 0.40. The value of Simplisia leaves E.japonica with a variation in comparison of solvents (6:6, 7:3, 8:2, 9:1) are 0.80, 0.64, 0.49 and 0.18.

Metabolite and expression profiling of steroidal alkaloids in wild tissues compared to bulb derived in vitro cultures of Fritillaria roylei – High value critically endangered Himalayan medicinal herb

Bulbous Fritillaria roylei (known as Jangli lahsan) is an important critically endangered medicinal herb of Astavarga group and widely used in traditional medicinal system. Being a medicinal potential but endangered herb, biotechnological interventions are urgently needed for its restoration and production of bioactive compounds. In the present study, in vitro cultures were established from bulb scales as explant by using optimized sterilization protocol (79.67% survival). From different combinations and concentrations of plant growth regulator tested; high efficiency callus induction (88.89%) and in vitro plantlets regeneration (77.78%) response was obtained in Murashige and Skoog medium supplemented with 0.5 mg/L thidiazuron +2.0 mg/L picloram and 1.0 mg/L kinetin +0.5 mg/L naphthaleneacetic acid, respectively. For the quantification of steroidal alkaloids i.e. sipeimine and peimine; selective, sensitive, and rapid liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) analytical method was developed and validated. Quantification of sipeimine and peimine was done for the first time in established in vitro cultures and naturally grown tissues of F. roylei i.e. bulbs, leaves, stem and flower bud. Among in vitro raised cultures, higher sipeimine content (1.98 μg/g) was detected in callus. Whereas, maximum sipeimine content (599.72 μg/g) was observed in floral bud compared to other wild tissues. Peimine content was detected in bulb (1.13 μg/g), leaf (0.78 μg/g) and stem (0.67 μg/g). Qualitative and quantitative phytochemical screening revealed potentiality of this important medicinal herb for commercial utilization in drug formulation to the industries. Maximum antioxidant activity (IC50) was exhibited in floral buds (0.11 mg/mL), while among in vitro raised cultures; regenerated plantlets (0.80 mg/mL) shown higher scavenging activity than callus (2.71 mg/mL). Higher total phenol content (42.86 μg gallic acid/mg) was observed in bulb whereas, flavonoids content is higher in leaves (68.36 μg quercetin/mg) followed by callus (58.22 μg quercetin /mg). Putative steroidal alkaloids gene expression studies using RT-qPCR showed positive correlation with metabolite content. For the first time, present investigation concluded that floral buds, leaves and stem could also be used as an alternative potential source for steroidal alkaloids and callus culture as sustainable approach for metabolite production to meet industrial standards and demands.

Chemotaxonomic studies on natural population of Gloriosa superba (L.) collected from Gangetic plain (India) and their invitro antigout activity for the identification of elite germplasm(s).

Gloriosa superba L. (Colchicaceae) is used in the treatment of gout and rheumatism as a traditional medicine dates back to 1810. It has also been used as ethnobotanical and folklore medicine to induce abortion/vaginal poison. The present study was carried out to identify the chemical variation existing in the major alkaloid metabolite (colchicine) in a threatened species, Gloriosa superba L. and is correlated with invitro antigout activity. The samples (tuber) were collected from their natural locations in Gangetic plain of India. HPLC-PDA quantification of colchicine was done on C18 column at 245nm and invitro antigout activity was analyzed by inhibition of protein denaturation, DPPH and Hydroxyl radical scavenging assay. The colchicine content within the 29samples ranges from 0.021 to 0.665% and the maximum contents was in NBG-10 from Kanth (U.P). Such high colchicine (0.665%) containing natural population of G. superba is reported for the first time in Indian population. Four chemotypes viz. NBG-10, NBG-120, NBG-126 and NBG-88 were selected on the basis of colchicine content for invitro antigout activity. NBG-10 was separated from rest of the population exhibiting the most promising activity with high colchicine content. The outcomes will be helpful in the identification of elite chemotype for herbal product development and quality check of metabolites in raw material. The study will also support the site-specific commercial cultivation to meet out the industrial demand as well as income generation to farmers.

Biodegradation of ritalinic acid by Nocardioides sp. – Novel imidazole-based alkaloid metabolite as a potential marker in sewage epidemiology

The consumption of methylphenidate, a nootropic drug used to improve mental performance, is becoming increasingly serious. Methylphenidate is metabolized in human liver to ritalinic acid, which has been commonly detected in sewage and surface waters. Additionally, ritalinic acid serves as a biomarker in sewage epidemiology studies. Thus knowledge of the stability and microbial degradation pathways of ritalinic acid is essential for proper estimation of methylphenidate consumption. In the study reported here, we describe the fast formation of a previously unknown, dead-end metabolite of ritalinic acid by Nocardioides sp. strain MW5. HRMS and 2D NMR analyses allowed precisely identification of the compound as an imidazole-based alkaloid cation with chemical formula 11‐[3‐(formylamino)propyl]‐1,2,3,4,6,7,8,9-octahydrodipyrido[1,2-a:1′,2′-c]imidazole-5-ium. In experiments, Nocardioides sp. strain MW5 transformed 34% of ritalinic acid into this metabolite, while 52% was mineralized into CO2. Alkaloid was not biodegraded during the OECD 301 F test. This study provides new insight into the environmental fate of methylphenidate and its metabolites. The data collected are essential for assessing nootropic drug consumption by sewage epidemiology and should lead to a better understanding of microbial degradation of ritalinic acid.

Potensi Madu sebagai Penurun Tekanan Darah dan Kolestrol

Hypertension is an increase in systolic and diastolic blood pressure more than 140/90 mmHg. Honey has the potential to reduce blood pressure because it has 200 chemical substances. This study aims to ford the effectiveness of giving honey to reduce blood pressure and cholesterol levels in hypertensive patients, as well as knowing the content of secondary metabolites found in honey. The research method used was semi quantitative with pre and post procedurs. Honey contains secondary metabolites of alkaloids, flavonoids, tannins, and saponins. The results of the analysis of honey give a significant decrease in systolic pressure, diastole, heart rate and cholesterol levels. Consumption honey regularly effectively reduces blood pressure in hypertensive patients.

New alkaloidal metabolites from cultures of entomopathogenic fungus Cordyceps takaomontana NBRC 101754

Two new alkaloidal metabolites, cordytakaoamides A (1) and B (2), as well as, 2-[(2-hydroxyethyl) amino] benzoic acid (3) and 2E-decenamide (4), and three known compounds (5–7) were isolated from ethyl acetate and n-butanol soluble portions of the entomopathogenic fungus, Cordyceps takaomontana NBRC 101754. Compounds 3 and 4 were isolated here for first time from natural resources. The chemical structures were established depending upon spectroscopic techniques such as 1D, 2D NMR, and HRMS. The absolute configuration of 1 and 2 was elucidated via the total synthesis of 1 as well as the experimental circular dichroism. Compound 3 was confirmed by a signal crystal X-ray analysis.

Variability in alkaloid and phenolic content vis-a-vis antigout potential among the natural population of Gloriosa superba (L.) collected from Central India

The variation in alkaloid metabolites (colchicine and gloriosine) was found significant in the nine germplasms of G. superba (L.), collected from Central India. The maximum content of colchicine and gloriosine was in NBG-15 (Chitrakoot, M.P) and NBG-13 (Bheraghat, M.P). The phenolic acids viz. quercetin and kaempferol was first ever quantified in G. superba tuber. Cluster analysis on chemical variability (colchicine and gloriosine content) results in the identification of three elite germplasm(s). The radical scavenging potential was also found promising in the selected elite germplasm viz. NBG-13, NBG-14 and NBG-15. Further, the protein denaturation potential of elite chemotypes was found at par with standard colchicine. The study will aid in site specific exploration of high metabolite yielding chemotype(s) with validated pharmacological action to meet out the industrial demands. This will also promotes the commercial cultivation of species for socio economical upliftment in the area having similar phyto geographical conditions.

Ekstraksi dan Identifikasi Komposisi Metabolit Fraksi Diklorometana dan Aquades Ektrak Metanol Daun Sirsak (Annona muricata Linn)

Sirsak adalah salah satu tumbuhan yang banyak dijumpai di daerah Nusa Tenggara Timur (NTT). Beberapa bagian tumbuhan sirsak diketahui telah banyak dimanfaatkan sebagai pengobatan tradisional ataupun sebagai peptisida alami. Pemanfaatan tumbuhan sebagai pengobatan ataupun sebagai peptisida alami tidak terlepas dari senyawa bioaktif yang terkandung didalamnya. Senyawa- senyawa tersebut akan berhasil diisolasi tergantung pemilihan pelarut. Penelitian ini dilakukan dengan tujuan mengetahui komposisi metabolit yang terkandung dalam setiap pelarut yang digunakan. Langkah-langkah penelitian ini meliputi preparasi sampel daun sirsak, ekstraksi secara maserasi dengan pelarut metanol, partisi ekstrak metanol dengan pelarut diklorometana dan air serta identifikasi komposisi metabolit dengan instrumen kromatografi cair kinerja tinggi (KCKT). Senyawa-senyawa yang teridentifikasi pada KCKT pelarut diklorometana diduga adalah senyawa metabolit golongan fenol, polikatida, tannin dan alkaloid. Sedangkan senyawa yang teridentifikasi KCKT pada pelarut air diduga adalah senyawa polar yang terikat dengan suatu gugus glikosida.

Aktivitas Antibakteri Ekstrak Batang Kecombrang (Etlingera elatior (Jack) R.M.Sm.) Terhadap Bakteri Plak Gigi Streptococcus mutans

Dental plaques are formed by biofilms that cover the surface of the tooth. Biofilm is a mucous layer consisting of millions of bacterial cells, saliva and food scraps. When biofilm formation is out of control, it will easily thicken on the tooth surface called plaque. This biofilm is a good place for colonization and growth of various types of bacteria, one of which is the Sterpotococcus mutans bacteria. S. mutans bacteria can form colonies that are firmly attached to the tooth surface and are cariogenic bacteria that are able to ferment sucrose (carbohydrates) into acid, reduce the pH of the tooth surface and cause tooth mineralization. So for the control of these bacteria, preparations containing antibacterials are used, one of which is natural ingredients, namely Kecombrang. The aim of this study was to determine the antibacterial activity of the Etlingera elatior (Jack) R.M.Sm. stem extract extracted by solvent based on the level of polarity. Antibacterial activity testing of extracts was divided into 5 groups, namely for n-hexane, ethyl acetate, ethanol extract 20, 40, 60 and 80%, positive control of minosep and negative control (DMSO). The test results showed that E. elatior (Jack) RMSm.) contained secondary metabolites of flavonoids, tannins, saponins, triterpenoids and alkaloids, ethyl acetate extracts with concentrations of 20, 40, 60 and 80%, having strong antibacterial activity against S. mutans of 17.22; 17,55; 17.77 and 18.55 mm, higher than the positive control of Minosep which has antibacterial activity of 16.55 mm.

1-Formyl-7-hydroxy-6,7-dihydro-5 H-pyrrolizine (1-CHO-DHP): A Potential Proximate Carcinogenic Metabolite of Pyrrolizidine Alkaloids.

Pyrrolizidine alkaloids (PAs) are phytochemicals present in more than 6000 plant species worldwide; about half of the PAs are hepatotoxic, genotoxic, and carcinogenic. Because of their wide exposure and carcinogenicity, the International Programme on Chemical Safety (IPCS) concluded that PAs are a threat to human health and safety. We recently determined that PA-induced liver tumor initiation is mediated by a set of four (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5 H-pyrrolizine (DHP)-DNA adducts and proposed that these DHP-DNA adducts are biomarkers of PA exposure and liver tumor initiation. To validate the generality of this metabolic activation pathway and DHP-DNA adducts as biomarkers, it is significant to identify reactive metabolites associated with this metabolic activation pathway. Segall et al. ( Segall et al. ( 1984 ) Drug Metab. Dispos. 12 , 68 - 71 ) previously reported that 1-formyl-7-hydroxy-6,7-dihydro-5 H-pyrrolizine (1-CHO-DHP) is generated from the metabolism of senecionine by mouse liver microsomes. In the present study, we examined the metabolism of seven hepatocarcinogenic PAs (senecionine, intermedine, retrorsine, riddelliine, DHR, heliotrine, and senkirkine) and one noncarcinogenic PA (platyphylline) by human, rat, and mouse liver microsomes. 1-CHO-DHP was identified as a common metabolite from the metabolism of these hepatotoxic PAs, but not from platyphylline. Incubation of 1-CHO-DHP with HepG2 and A549 cells produced the same set of DHP-DNA adducts, which were identified by both LC/MS MRM mode and selected ion monitoring analyses through comparison to synthetic standards. In the incubation medium of 1-CHO-DHP treated HepG2 cells, both DHP and 7-cysteine-DHP were formed, which were capable of binding to cellular DNA to produce DHP-DNA adducts. These results suggest that 1-CHO-DHP is a proximate DNA metabolite of genotoxic and carcinogenic PAs.

Development of an Efficient Extraction Method for Separating Solasodine, an Steroidal Alkaloid, From an Oily Matrix: A Comparison Between LLE and SPE

Aims: In many references of Traditional Iranian Medicine (TIM), there are methods to produce medicinal products from plant fruit based on extraction of active substances into oils. One of these recommendations is to import cucurbit or pumpkin seed oil into an entirely ripe fruit of Solanum melongena plant. In this study for the first time, the extraction of solasodine from the oily matrix has been investigated to find a precise method with suitable extraction recovery.
 Study Design: Original Research Article.
 Place and Duration of Study: The study took place in herbal and traditional medicines research center of Kerman, Iran from February 2015 to November 2017.
 Methodology: Solasodine, an active steroidal alkaloid metabolite of the plant, was used for standardization of the product. Two methods of (Liquid-liquid extraction) LLE and (Solid phase extraction) SPE were evaluated and their conditions were optimized by assessment of seven effective factors at five levels using HPLC as the method of choice for solasodine determination.
 Results: Results showed that LLE and SPE in optimized conditions had recoveries of about 76.5 and 94.7%, respectively. For the extraction of low concentrations of the analyte, the SPE method had better accuracies (88 to 105%), but its precision was less than that of LLE method. In contrast, the LLE method had a higher precision in the whole range while its relevant accuracy was lower. The LOD and LOQ of SPE-HPLC method were 0.2 and 0.6 μg/ml and those of the LLE-HPLC method were 0.2 and 0.7 μg/ml, respectively.
 Conclusion: In general, both methods of LLE-HPLC and SPE-HPLC showed acceptable validation parameters including linearity, precision, accuracy, LOD, and LOQ; and they can be used for routine extraction and determination of solasodine in traditional medicine products.

Comparison of Secondary Metabolite Content of Pteris vittata L. in Baluran National Park and Malang and Its Effect on Environment

Fern is cosmopolitan plants which are almost scattered in all parts of the world, one of which is found in Baluran National Park and in Malang. The potential and benefits of these ferns are quite important for agriculture and medicine because of the chemical compounds they have, especially in Pteris vitatta L. This study aimed to analyze secondary metabolites contained in P. vittata L. in Baluran National Park, Situbondo and in Malang. The samples used were leaves and rhizome P. vittata extracted using methanol 96%, followed by a qualitative test of the content of alkaloids, flavonoids, terpenoids, polyphenols, tannins, saponins, using phytochemical screening methods with several reagents. The results showed that the leaves and Rhizome P. vittata L.. in Baluran National Park, Situbondo were positively containing secondary metabolites of terpenoids, polyphenols, tannins, saponins, and alkaloids (Dragendorf and Bouchardat reagents), whereas flavonoids were not present in all samples. However, the results of P. vitatta L. phytochemical screening around Malang State University positively contained flavonoids, polyphenols, terpenoids, alkaloids (Wagner and Dragendorf reagents). The difference in results from these two places is because the secondary metabolite content in plants is affected by stressful environmental conditions such as soil texture where it is grown or is affected by the precursors of the secondary metabolites of the metabolites.

Bacterial Analogs of Plant Tetrahydropyridine Alkaloids Mediate Microbial Interactions in a Rhizosphere Model System.

Plants expend significant resources to select and maintain rhizosphere communities that benefit their growth and protect them from pathogens. A better understanding of assembly and function of rhizosphere microbial communities will provide new avenues for improving crop production. Secretion of antibiotics is one means by which bacteria interact with neighboring microbes and sometimes change community composition. In our analysis of a taxonomically diverse consortium from the soybean rhizosphere, we found that Pseudomonas koreensis selectively inhibits growth of Flavobacterium johnsoniae and other members of the Bacteroidetes grown in soybean root exudate. A genetic screen in P. koreensis identified a previously uncharacterized biosynthetic gene cluster responsible for the inhibitory activity. Metabolites were isolated based on biological activity and were characterized using tandem mass spectrometry, multidimensional nuclear magnetic resonance, and Mosher ester analysis, leading to the discovery of a new family of bacterial tetrahydropyridine alkaloids, koreenceine A to D (metabolites 1 to 4). Three of these metabolites are analogs of the plant alkaloid γ-coniceine. Comparative analysis of the koreenceine cluster with the γ-coniceine pathway revealed distinct polyketide synthase routes to the defining tetrahydropyridine scaffold, suggesting convergent evolution. Koreenceine-type pathways are widely distributed among Pseudomonas species, and koreenceine C was detected in another Pseudomonas species from a distantly related cluster. This work suggests that Pseudomonas and plants convergently evolved the ability to produce similar alkaloid metabolites that can mediate interbacterial competition in the rhizosphere.IMPORTANCE The microbiomes of plants are critical to host physiology and development. Microbes are attracted to the rhizosphere due to massive secretion of plant photosynthates from roots. Microorganisms that successfully join the rhizosphere community from bulk soil have access to more abundant and diverse molecules, producing a highly competitive and selective environment. In the rhizosphere, as in other microbiomes, little is known about the genetic basis for individual species' behaviors within the community. In this study, we characterized competition between Pseudomonas koreensis and Flavobacterium johnsoniae, two common rhizosphere inhabitants. We identified a widespread gene cluster in several Pseudomonas spp. that is necessary for the production of a novel family of tetrahydropyridine alkaloids that are structural analogs of plant alkaloids. We expand the known repertoire of antibiotics produced by Pseudomonas in the rhizosphere and demonstrate the role of the metabolites in interactions with other rhizosphere bacteria.