Biological Activities of Withanolides from Datura innoxia

Aims: This study aimed to explore the therapeutic potential of Datura innoxia through the chemoinformatic and antibacterial evaluation of withanolides extracted from it. Study Design: The pharmacokinetic and pharmacodynamic properties and drug-likeness of the withanolides—withametelinol A, withametelinol B, witharifeen, withametelin, dinoxin B, and daturalicin—of D. innoxia were analyzed using the SwissADME program. Schrodinger software was used to target and evaluate their antibacterial potentialities through docking studies. The penicillin-binding protein, DNA gyrase, efflux pump protein, and quorum sensing regulators of S. aureus and E. coli were selected as target proteins for assessing protein–ligand interactions. All observations were comparatively analyzed with the properties of withanolide A and withaferin A, the best-known withanolides. Most active dinoxin B withanolide (12500–100000 μg/ml) extracted from leaves of Datura innoxia; was subjected to antibacterial assay against methicillin-resistant S. aureus (MRSA) and multi-drug resistant(MDR) E. coli isolated from the urine samples of urinary tract infected patients. Results: In-silico studies revealed the therapeutical properties of various withanolides present in D. innoxia. In particular, the drug-likeness and antibacterial properties of withametelin and dinoxin B were significantly and remarkably high due to their binding affinity toward cell membrane proteins. Docking studies have shown that the efflux pump protein of E. coli and penicillin-binding proteins of S. aureus to be the ligand -interaction targets. A significant antibacterial assay revealed that the MRSA isolates were susceptible to dinoxin B, with a zone of inhibition of 21±0.5 mm to 24±0.5 mm, and the bacteria were susceptible at a concentration rate of ≤ 12.5 mg/ml. Conclusion: It is crucial to bring awareness of the therapeutical importance of D. innoxia and to preserve this vital plant from being largely destroyed. As computational studies promote the effective selection of drug molecules, this research also helps to select the best compound for further clinical analysis.

Citrus scented natural essential oils for crystal salt deodorant

Alum natural mineral salt is the world's leading crystal deodorant which works in removing unpleasant body smell. Some other products attempt to block the sweat pores with harmful chemicals such as aluminum chlorohydrates or aluminum zirconium. However, crystal is hypoallergenic deodorant that is healthy, safe, and effective in inhibiting odor formation on the axillary. The light scent infused with natural essential oils might enhance the properties of the crystal deodorant and its antimicrobial activity in fighting against body odor bacteria. This study was conducted to evaluate the potential antimicrobial activity of both citrus essential oils and alum salt. The essential oils were extracted from Citrus aurantifolia, and Citrus sinensis peels by water-steam distillation and analysed using gas chromatography-mass spectrometry (GC-MS). Antibacterial assay against Escherichia coli was carried out on the extracted essential oils using paper disc diffusion assay. Results showed that no lead and cadmium constituents were detected, while low concentration of iron (0.993 ± 0.0059 ppm) and copper (0.134 ± 0.0078 ppm) were detected in the crystal salt (15% w/v). D-limonene, decanal and citral were major components responsible for the citrus scents aroma. The C. aurantifolia essential oil and 15% w/v alum salt were active against E. coli with inhibitory zones at 7.23 ± 0.15 mm and 11.13 ± 0.51 mm respectively. The citrus scented crystal deodorant was successfully developed and tested.

Crystal structure and Biological evolution of 5-bromothiophene based 3,4-dihydropyrimidin-2-(1H)-thi(ones)

Herein, Solvent-free synthesis of 5-bromothiophene based 3,4-dihydropyrimidin-2-(1H)-thi(ones) was explored. The main advantages of this study are that pure product comes in hand with easy workup and without using any separation technique, a good amount of yield, and formation of product in crude form. We developed a single crystal of 4c, and we analysed crystal structure by Hirshfeld surfaces analysis. All the synthesised compounds were screened for antifungal and antibacterial assay. Among all synthesised compounds, 4a, 4b and 4j have potent antibacterial activity. While 4f, 4g, 4h and 4i show good antifungal activity among all synthesised compounds. We also carried out ADMET prediction for the 4(a-j), and calculated data show that all the compounds have prominent drug-like nature.

Physicochemical and antibacterial activities of Apis honey types derived from Coorg, Karnataka, India

Natural honey has various ingredients in it that contribute to its incredible properties. The aim of this investigation was to evaluate the physicochemical and antibacterial activity of various Apis honey from Coorg, Karnataka. Four samples of Apis honey viz., A. florea, A. mellifera, A. cerana and A. dorsata were collected from various regions of Coorg, Karnataka. The honey samples' physicochemical properties and antibacterial activities against Streptococcus sp., Staphylococcus aureus, Bacillus subtilis and Enterococcus sp were determined in vitro. The moisture and ash content varied from 13.6 - 17.2% and 0.32 – 0.49%, respectively. Hydroxy methyl furfurals) content of A. dorsata honey samples was highest with 9.2±0.5 mg/Kg and least was recorded with 6.8±0.4 mg/Kg for A. florae honey. The reducing sugar content of A. florea honey sample was highest with 87.5±3.2 (%) and the peroxide levels were in the range of 10.2 – 14.9 µg/g/h at 20°C. The antibacterial assay revealed that S. aureus, Enterococcus sp and Streptococcus sp were most susceptible against the honey varieties tested and minimum inhibitory concentration (MIC) values between 25-6.5 (%v/v) were determined. In conclusion, honey varieties from Coorg could be used in specific antibacterial prophylaxis as the activity depends on the honey bee species, their metabolism and floral sources in specific geographical regions.

Kandungan Fitokimia, Potensi Antibakteri dan Antioksidan Hasil Ekstraksi Caulerpa racemosa dengan Pelarut Berbeda

Caulerpa racemosa merupakan rumput laut hijau yang mengandung senyawa aktif yang berpotensi sebagai antibakteri dan antioksidan. Perbedaan profil fitokimia dan bioaktivitas suatu ekstrak dipengaruhi oleh kepolaran pelarut ekstraksi. Penelitian ini bertujuan untuk mempelajari profil fitokimia, aktivitas antibakteri dan antioksidan ekstrak C. racemosa. Ekstrak diperoleh dari sampel segar C. racemosa yang dimaserasi menggunakan pelarut n-heksana, etil asetat, dan metanol. Uji antibakteri dilakukan dengan metode Resazurin Microtitter Assay (REMA) terhadap bakteri Escherichia coli dan Staphylococcus aureus. Aktivitas antioksidan diuji menggunakan metode 1,1-diphenyl-2-picrylhydrazyl (DPPH) dan Ferric Reducing Antioxidant Power (FRAP). Hasil penapisan fitokimia memperlihatkan bahwa ekstrak n-heksana mengandung alkaloid dan triterpenoid, sedangkan ekstrak etil asetat dan metanol mengandung alkaloid, flavonoid, tanin, fenol, dan steroid. Aktivitas antibakteri terbaik ditunjukkan oleh ekstrak etil asetat dengan nilai Minimum Inhibitory Concentration (MIC) terhadap E. coli sebesar 250 mg/mL. Ekstrak etil asetat C. racemosa juga memperlihatkan aktivitas antioksidan terbaik dengan nilai IC50 DPPH sebesar 110,7 mg/mL dan nilai FRAP sebesar 96,68 mmol Fe (II)/g. ABSTRACTCaulerpa racemosa is a green seaweed that contains active compounds that are potential for antibacterial and antioxidant. The phytochemical constituents and bioactivity of an extract depend on the extraction solvent polarity. This study aimed to determine the phytochemical profiles, antibacterial and antioxidant activity of C. racemosa extracts. Extracts were obtained from the fresh C. racemosa samples that were macerated with n-hexane, ethyl acetate, and methanol. Antibacterial assay was tested by Resazurin Microtiter Assay (REMA) method against Escherichia coli and Staphylococcus aureus. Antioxidant activity was determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) method. Phytochemical screening showed that n-hexane extract contained alkaloid and triterpenoid, while ethyl acetate and methanol extracts contained alkaloids, flavonoids, tannins, phenols, and steroids. The most active extract in the antibacterial assay was ethyl acetate extract with a Minimum Inhibitory Concentration (MIC) value of 250 mg/mL against E. coli. Ethyl acetate extract of C. racemosa also showed the best antioxidant activity where the IC50 of DPPH value was 110.7 mg/mL and the FRAP value was 96.68 mmol Fe(II)/g.

High hydrostatic pressure shapes the development and production of secondary metabolites of Mariana Trench sediment fungi

The hadal biosphere is one of the least understood ecosystems on our planet. Recent studies have revealed diverse and active communities of prokaryotes in hadal sediment. However, there have been few studies on fungi in hadal sediment. Here we report the first isolation and cultivation of 8 fungi from the Mariana Trench sediment. The individual colonies were isolated and identified as Stemphylium sp., Cladosporium sp., Arthrinium sp., Fusarium sp., Alternaria sp., and Aspergillus sp. High hydrostatic pressure (HHP) test was carried out to identify the piezophily of these hadal fungi. Among them, 7 out of the 8 fungal isolates exhibited the ability of germination after incubation under 40 MPa for 7 days. Vegetative growth of the isolates was also affected by HHP. Characterization of secondary metabolites under different pressure conditions was also performed. The production of secondary metabolites was affected by the HHP treatment, improving the potential of discovering novel natural products from hadal fungi. The antibacterial assay revealed the potential of discovering novel natural products. Our results suggest that fungal growth pressure plays an important role in the development and production of secondary metabolites of these hadal fungi under the extreme environment in the Mariana Trench.

Potency of Endophytic and Rhizospheric Bacteria of Akar Kucing (Acalypha indica Linn.) as Antibacteria against Klebsiella pneumoniae

The prevalence of pneumonia in Indonesia was 2% in 2018. Treatment of pneumonia using antibiotics caused resistance to pathogenic bacteria. Endophytic and rhizospheric bacteria from the medicinal plant Acalypha indica Linn., is a new type of bacteria that produces antibacterial compounds against Klebsiella pneumoniae. This study aims to analyze the potency and identify endophytic and rhizospheric bacteria of the A. indica Linn as an antibacterial of K. pneumoniae. The research includes isolation and purification of endophytic and rhizospheric bacteria of the A. indica Linn, antagonistic assay of bacteria cell culture, antibacterial assay of bacteria metabolites, and identification of potential isolates based on 16S rDNA sequence similarity. The results showed that number of rhizosphere bacteria 6.83 × 105 CFU/g was more than endophytic bacteria 1.78 × 104 CFU/g. Diversity of rhizosphere bacterial 0.72 was higher than endophytic bacteria 0.62. The rhizospheric bacteria RU112B and RU315B had the highest activity to inhibit the growth of K. pneumoniae. Both isolates RU112B and RU315B were identified as Staphylococcus saprophyticus with a similarity 99.83% and Luteimonas terrae with a similarity 99.67% respectively

Antibacterial and Zebrafish-based Screening for Wnt Signal Inhibitory Activities of Syzygium polycephaloides (C.B. Robb. Merr.) Bark Extracts

Syzygium polycephaloides, a plant native to Southeast Asia, is used to cure common illnesses. In this study, the methanolic bark extracts of S. polycephaloides was evaluated for their antibacterial activity and screened for their Wnt signal inhibitory activity using zebrafish-based assay. In the antibacterial assay, the extracts were tested against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeroginosa, and Escherichia coli using disk diffusion assay. On the other hand, zebrafish-based screening was used to determine the inhibitory potential of S. polycephaloides against the Wnt signal. Zebrafish embryos were treated with LiCl to upregulate the Wnt signal which produces eyeless phenotype. The methanolic extracts had antibacterial activity against the test microorganisms except P. aeruginosa. After fractionation, ethyl acetate (EtOAc) and aqueous fractions exhibited wide-spectrum antibacterial activity. For the Wnt signal inhibitory activity screening, the LiCl-treated embryos were rescued to their normal eye development after treatment with the S. polycephaloides bark extracts (100 g/mL). The results suggest that the extracts may have inhibited the Wnt signal. This study shows that the S. polycephaloides is a potent source of antibacterial compounds and Wnt inhibitors.

Bioactivity guided extraction of PDHC [3,3’-(propane-2,2-diyl)bis(3,4,5,6,7,8- hexahydro-1h-isochromene)]: A Novel antibacterial compound from an ornamental plant Polyalthia longifolia

Objective: The objective of the study was to determine and compare the antibacterial effect of different ornamental plants and to isolate the effective bioactive compound with antibacterial activity from Polyalthia longifolia. Methods: Petroleum ether and methanol extracts of Bougainvillea glabra, Polyalthia longifolia, Ixora coccinea Linn. ,Plumeria rubra and Euphorbia milli leaves were investigated for antimicrobial activity by performing agar well difusion method. The plant extract with the highest antibacterial activity was selected and further used for the isolation of antibacterial compounds. In silico docking studies and in vitro antibacterial assay was performed to analyze the biological activity of pure compound. Results: The highest antibacterial activity was found in the pet ether of Polyalthia longifolia against all the tested bacterial strains and the extract was further selected for compound separation. A novel compound 3,3’-(propane-2,2-diyl)bis(3,4,5,6,7,8-hexahydro-1H-isochromene) (PHDC) with a molecular weight of 316.35 g/mol and molecular formula C21H32O2 was identified from Polyalthia longifolia by using spectroscopic studies. In the in vitro antibacterial assay, PHDC demonstrated significant antibacterial showed against Protease mirabilis. In silico docking studies revealed that PHDC showed antibacterial activity by inhibiting tRNA Synthetase (IleRS). PHDC exhibited the lowest binding energy of - 8.7Kcal/Mol for Isoleucyl tRNA Synthetase (IleRS), the protein responsible for protein synthesis. Conclusion: The emergence of multiple antibiotics resistant microbes has become huge nowadays and the infections caused by these resistant microbes cannot be treated with antibiotics. PHDC is a novel compound extracted from Polyalthia longifolia showed significant antibacterial effect and we suggest that the compound can be further used as lead molecules to overcome the infections caused by antibiotic resistant bacteria.