scholarly journals Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

2021 ◽  
Vol 17 ◽  
pp. 2390-2398
Author(s):  
Emmanuel Tope Oluwabusola ◽  
Olusoji O Adebisi ◽  
Fernando Reyes ◽  
Kojo S Acquah ◽  
Mercedes De La Cruz ◽  
...  

Five new phenolic siderophores 1–5 were isolated from the organic extract of a culture broth in a modified SGG medium of Pseudomonas sp. UIAU-6B, obtained from sediments collected from the Oyun river in North Central Nigeria. The structure of the new compounds, pseudomonin A–C (1–3) and pseudomobactin A and B (4 and 5) isolated alongside two known compounds, pseudomonine (6) and salicylic acid (7), were elucidated based on high-resolution mass spectrometry, 1D and 2D NMR analyses. The absolute configuration of the threonine residue in compounds 1–5 was determined by Marfey analysis. The antimicrobial evaluation of compound 4 exhibited the most potent activity against vancomycin-sensitive Enterococcus faecium VS144754, followed by 3 and 5, with MIC values ranging from 8 to 32 µg/mL. Compounds 2 and 3 exhibited moderate activity against Mycobacterium tuberculosis H37Rv, with MIC values of 7.8 and 15.6 µg/mL, respectively. Plausible biosynthetic hypotheses toward the new compounds 1–5 were proposed.

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Rizwana Sarwar ◽  
Umar Farooq ◽  
Sadia Naz ◽  
Nadia Riaz ◽  
Syed Majid Bukhari ◽  
...  

Two new compounds [1-2] were purified from ethyl acetate fraction of Quercus incana. The structure of these compounds is mainly established by using advanced spectroscopic technique such as UV, IR, one-dimensional (ID) and two-dimensional (2D) NMR techniques, and EI mass. The structural formula was deduced to be 4-hydroxydecanoic acid [1] and 4-hydroxy-3-(hydroxymethyl) pentanoic acid [2]. Both isolated compounds were tested for their antimicrobial potential and showed promising antifungal activity against Aspergillus niger and Aspergillus flavus.


2014 ◽  
Vol 9 (2) ◽  
pp. 1934578X1400900
Author(s):  
Suciati ◽  
Mary J. Garson

This study reports the isolation and characterization of three new tetrapeptides, apicidins G (1), H (2) and I (3), along with the known apicidin (4), apicidin A (5), apicidin C (6), diketopiperazine 7, equisetin (8) and 7-hydroxy-2-(2-hydroxypropyl)-5-methylchromone (9). The structures of the new compounds were deduced by 2D NMR spectroscopic and MS data.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sara Soroury ◽  
Mostafa Alilou ◽  
Thomas Gelbrich ◽  
Marzieh Tabefam ◽  
Ombeline Danton ◽  
...  

AbstractThree new compounds (1–3) with unusual skeletons were isolated from the n-hexane extract of the air-dried aerial parts of Hypericum scabrum. Compound 1 represents the first example of an esterified polycyclic polyprenylated acylphloroglucinol that features a unique tricyclo-[4.3.1.11,4]-undecane skeleton. Compound 2 is a fairly simple MPAP, but with an unexpected cycloheptane ring decorated with prenyl substituents, and compound 3 has an unusual 5,5-spiroketal lactone core. Their structures were determined by extensive spectroscopic and spectrometric techniques (1D and 2D NMR, HRESI-TOFMS). Absolute configurations were established by ECD calculations, and the absolute structure of 2 was confirmed by a single crystal determination. Plausible biogenetic pathways of compounds 1–3 were also proposed. The in vitro antiprotozoal activity of the compounds against Trypanosoma brucei rhodesiense and Plasmodium falciparum and cytotoxicity against rat myoblast (L6) cells were determined. Compound 1 showed a moderate activity against T. brucei and P. falciparum, with IC50 values of 3.07 and 2.25 μM, respectively.


2010 ◽  
Vol 5 (12) ◽  
pp. 1934578X1000501 ◽  
Author(s):  
Rashad Mehmood ◽  
Abdul Malik

Crotosparsamide (1), a new cyclic nonapeptide, has been isolated from the n-butanol soluble sub-fraction of Croton sparsiflorus along with p-hydroxy methylcinnamate and kaempferol, which are reported for the first time from this species. Their structures were determined by chemical and spectral studies including ESIMS, and 1D and 2D NMR spectroscopic data.


2012 ◽  
Vol 7 (12) ◽  
pp. 1934578X1200701 ◽  
Author(s):  
Rafaela Ferreira Oliveira ◽  
Celso Amorim Camara ◽  
Maria de Fátima Agra ◽  
Tania Maria Sarmento Silva

Investigation of the green fruits of Clusia paralicola (Clusiaceae) led to the isolation and characterization of two 3,8″-biflavonoids, 2R, 3S, 2″R, 3″R-GB1-7″- O-β-glucoside (1) and 2R, 3S, 2″R, 3,8″-binaringenin-7″-O-β-glucoside (2), together with four known compounds: β-sitosterol, stigmasterol, β-amyrin, and epicatechin. The structures were established from the IR, LC-ESI-MS and NMR spectral data, including 2D-NMR experiments. The absolute configurations of 1 and 2 were determined by CD spectra. The total extract and the biflavonoids demonstrated significant antioxidant activity in DPPH, ABTS, and β-carotene/linoleic acid tests.


2019 ◽  
Vol 24 (2) ◽  
pp. 7-16
Author(s):  
Nabin Rana ◽  
Saraswoti Khadka ◽  
Bishnu Prasad Marasini ◽  
Bishnu Joshi ◽  
Pramod Poudel ◽  
...  

 Realizing myxobacteria as a potential source of antimicrobial metabolites, we pursued research to isolate myxobacteria showing antimicrobial properties. We have successfully isolated three strains (NR-1, NR-2, NR-3) using the Escherichia coli baiting technique. These isolates showed typical myxobacterial growth characteristics. Phylogenetic analysis showed that all the strains (NR-1, NR-2, NR-3) belong to the family Archangiaceae, suborder Cystobacterineae, and order Myxococcales. Furthermore, 16S rRNA gene sequence similarity searched through BLAST revealed that strain NR-1 showed the closest similarity (91.8 %) to the type strain Vitiosangium cumulatum (NR-156939), NR-2 showed (98.8 %) to the type of Cystobacter badius (NR-043940), and NR-3 showed the closest similarity (83.5 %) to the type of strain Cystobacter fuscus (KP-306730). All isolates showed better growth in 0.5-1 % NaCl and pH around 7.0, whereas no growth was observed at pH 9.0 and below 5.0. All strains showed better growth at 32° C and hydrolyzed starch, whereas casein was efficiently hydrolyzed by NR-1 and NR-2. Besides, preliminary antimicrobial tests from crude extracts showed activities against Gram-positive, Gram-negative bacteria, and fungi. Our findings suggest that the arcane soil habitats of Nepal harbor myxobacteria with the capability to produce diverse antimicrobial activities that may be explored to overcome the rapidly rising global concern about antibiotic resistance.


2020 ◽  
Vol 19 (12) ◽  
pp. 1525-1536
Author(s):  
Boontiya Chuankid ◽  
Hedda Schrey ◽  
Benjarong Thongbai ◽  
Olivier Raspé ◽  
Norbert Arnold ◽  
...  

AbstractSubmerged cultures of the edible mushrooms Phlebopus portentosus and Phlebopus spongiosus were screened for their secondary metabolites by HPLC-UV/Vis and HR-LC-ESI-MS. Two new compounds, 9′-hydroxyphenyl pulvinone (1), containing an unusual pulvinone structure, and phlebopyron (2), together with the seven known pigments, atromentic acid (3), xerocomic acid (4), variegatic acid (5), methyl atromentate (6), methyl isoxerocomate (7), methyl variegatate (8), and variegatorubin (9) were isolated from the cultures. Their structures were assigned on the basis of extensive 1D/2D NMR spectroscopic analyses, as well as HR-ESI-MS, and HR-ESI-MS/MS measurements. Furthermore, the isolated compounds were evaluated for their antimicrobial and cytotoxic properties. 9′-hydroxyphenyl pulvinone (1), xerocomic acid (4), and methyl variegatate (8) exhibited weak to moderate cytotoxic activities against several tumor cell lines. The present paper provides a comprehensive characterization of pigments from the class of pulvinic acids that are present in the basidiomes of many edible bolete species.


2012 ◽  
Vol 5 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Zia Muhammad ◽  
Shabir Ahmad ◽  
Riaz Ullah ◽  
Farman Ullah ◽  
Saleem Jan

Author(s):  
Batsuren D ◽  
Batbayar N ◽  
Tunsag J

Since 1986 we started investigating diterpene alkaloids from Aconitum and Delphinum species in Mongolia. Alkaloid composition of some 12 species of Aconitum and Delphinum of Ranunculaceae family and 63 individual compounds were isolated and identified. Among them 9 were newly found naturally-occurring compounds and structure of these alkaloids were elucidated completely. High resolution Mass-spectrometry, 1H and 13C NMR, 2D NMR techniques such as COSY, HMQC, HMBC were employed to elucidate structure of new compounds. Structure of altaconitine was elucidated and confirmed by applying X-ray crystallographic analysis in addition to above- mentioned techniques. As a result of our long-term chemical in-vestigation of plant species of Mongolia, we have observed and established that secondary metabolites such as alkaloids, coumarins, lignans and xanthones accumulate in more oxidized form in plant species grown in Mongolia. This principle is also demonstrated in the structure of diterpenoid alkaloids isolated from plants of Ranunculaceae family grown in Mongolia. As can be seen from alkaloids 11-acetyl-1, 19-epoxydenudatine and turpelline each contain 4 oxygen atoms, which is more oxygen atoms than in commonly-occurring C-20 diterpenoid alkaloids. Except turpelline no other C-20 alkaloid containing four hydroxyl groups was found in nature. Altaconitine is a newly discovered alkaloid which contains functional groups with highest number of oxygen atoms among C-19 diterpenoid alkaloids. Ring “A” in altaconitine structure is substituted at C-1, C-2 and C-3 positions with 2, 3-transdiol system, making altaconitine a unique structure found in nature. Хорс ба Гэзэг цэцгийн төрлийн ургамлын дитерпений алкалоид Хураангуй: Дэлхий дахинаа Aconitum, Astagne, Consolida, Delphinum ба Inula-гийн төрлийн ургамлууд нь дитерпений алкалоидын баялаг эх сурвалж бөгөөд манай оронд тэдгээрээс Хорс ба Гэзэг цэцэгийн төрлийн ургамлууд элбэг тохиолддог. Холтсон цэцгийн овгийн Хорс ба Гэзэг цэцэгийн төрөлд хамаарагдах 12 зүйл ургамалд дитерпений алкалоидын судалгаа явуулж, дээрхи ургамлуудаас С-19, С-20 дитерпений алкалоидод хамаарагдах 63 бодисыг химийн цэвэр байдлаар ялгаж, тэдгээрийн бүтцийг таньж тодорхойлсоны дотор 9 дитерпений шинэ алкалоидыг анх удаа байгалиас олсон. Эдгээрийн дотроос бүтцийн хувьд нилээд сонирхолтой нь альтаконитин бөгөөд тэр нь 6 хираль нүүрстөрөгчийн атом агуулсан цууны ба бензоины хүчлээр ацилжсан, үндсэн цагиргийн 10 нүүрстөрөгчийн атом нь хүчилтөрөгч бүхий халагч бүлэгтэй ба ялангуяа “А” цагиргийн 2 ба 3-р байрлалд буй гидроксил бүлгүүд нь транс диол систем бүхий рекорд исэлдсэн хэлбэртэй, өвөрмөц бүтэц бүхий байгалийн шинэ алкалоид юм. Түүнчлэн турпеллин алкалоид нь үндсэн цагиргийн 4 нүүрстөрөгчийн атом нь хүчилтөрөгч бүхий халагч бүлэгтэй байгаа нь тус алкалоид бүтцийн хувьд рекорд исэлдсэн напеллины төрлийн цорын ганц нэгдэл болж бүртгэгдээд байна. Түлхүүр үгс: Хорс, Гэзэг цэцэг, дитерпений алкалоид


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