scholarly journals Study to find the best extraction solvent for use with guava leaves ( Psidium guajava L.) for high antioxidant efficacy

2014 ◽  
Vol 2 (2) ◽  
pp. 174-180 ◽  
Author(s):  
Jongkwon Seo ◽  
Soojung Lee ◽  
Marcus L. Elam ◽  
Sarah A. Johnson ◽  
Jonghoon Kang ◽  
...  
Keyword(s):  
Psidium Guajava ◽  
Extraction Solvent ◽  
Guava Leaves

scholarly journals Diversity of Neopestalotiopsis and Pestalotiopsis spp., Causal Agents of Guava Scab in Colombia

Plant Disease ◽  
2018 ◽  
Vol 102 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Fernando Solarte ◽  
Carlos German Muñoz ◽  
Sajeewa S. N. Maharachchikumbura ◽  
Elizabeth Álvarez
Keyword(s):  
Central America ◽  
Internal Transcribed Spacer ◽  
Geographical Origin ◽  
Elongation Factor ◽  
Psidium Guajava ◽  
Economic Importance ◽  
Fruit Tree ◽  
Multiple Gene ◽  
Guava Leaves ◽  
Β Tubulin

Common guava (Psidium guajava L.) is a fruit tree of global economic importance. It is grown in Asia, South and Central America, and Hawaii for its exquisite aroma and flavor, and nutritional and medical properties. However, guava production is limited by guava scab, caused by fungi in the Pestalotiopsis genus. Characteristic symptoms of guava scab are corky, ovoid or round lesions on fruit surfaces. These lesions may thicken, affecting the flesh below and reducing fruit quality and commercial value. We characterized 81 isolates isolated from guava scab lesions on guava leaves and fruit in different regions of Colombia, and identified them as Pestalotiopsis and Neopestalotiopsis spp. We analyzed the morphology, pathogenicity, and genetic diversity of the isolates based on the sequences of the internal transcribed spacer, β-tubulin, and elongation factor genes. Isolates were morphologically, pathogenically, and genetically diverse but the diversity did not correlate with geographical origin, or guava cultivar or tissue from which the isolates were recovered. Selected monosporic isolates included in the multiple-gene analysis were identified as belonging to two genera: Neopestalotiopsis (65 isolates with versicolorous conidia) and Pestalotiopsis (4 isolates with concolorous conidia).

scholarly journals EFEKTIVITAS INFUSA DAUN JAMBU BIJI (Psidium guajava) SEBAGAI PRESERVATIF ALAMI PADA KARKAS PUYUH

2021 ◽  
Vol 46 (2) ◽  
pp. 127
Author(s):  
Eulis Tanti Marlina ◽  
Ellin Harlia ◽  
Yuli Astuti Hidayati ◽  
Deden Zamzam Badruzzaman ◽  
Wowon Juanda
Keyword(s):  
Shelf Life ◽  
Experimental Method ◽  
Psidium Guajava ◽  
Antimicrobial Compounds ◽  
Natural Preservative ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Guava Leaves ◽  
Total Bacteria

Guava leaves can be used as a natural preservative in quail carcass because they contain antimicrobial compounds such as flavonoid and tannin. This study studied the effect of using guava leaves infusion on quail carcass on the total bacteria, Enterobacteriaceae, and early spoilage.  The research used an experimental method with a completely randomized design, 3 treatments of guava leaves infusion concentration, namely P1 = 25%, P2 = 50%. And P3 = 75%, each treatment was repeated 6 times.  The application of infusion to quail carcass was carried out by immersion for 15 minutes.  Data were analyzed using ANOVA and Turkey’s test.  The results showed that the total bacteria and Enterobacteriaceae before immersion were 3.80 x 107 cfu/g and 1.90 x 104 cfu/g, respectively.  Soaking quail carcass in guava leaves infusion was able to reduce the total bacteria and Enterobacteriaceae to 72.15% and 78.50%, respectively.  The early spoilage was inversely proportional to the total bacteria and Enterobacteriaceae resulted in longer shelf life.

The Potential of Quercetin in Psidium guajava L. Leaves Extract as Bioinhibitor for Controlled Released Fertilizer

2014 ◽  
Vol 970 ◽  
pp. 16-19
Author(s):  
Nur Kamila Ramli ◽  
Zahid Majeed ◽  
Anis Shuib ◽  
Nurlidia Mansor ◽  
Zakaria Man
Keyword(s):  
Natural Products ◽  
Ammonia Concentration ◽  
Psidium Guajava ◽  
Fertilizer Application ◽  
Small Reduction ◽  
Anti Cancer ◽  
Anti Oxidant ◽  
Urease Inhibitory ◽  
Guava Leaves ◽  
Controlled Released

This study was done to investigates the usage of natural products as one of the materials in fertilizer application. Urease inhibitors that are commonly used in agriculture are usually chemical based which affects the environment. Introducing natural products will ensure biodegradability of the material. Psidium Guajava L. (guava) has been reported to have properties such as antibacterial, anti-oxidant, anti-cancer, and anti ulcer for medical purposes. Guava leaves extract contains an active compound named quercetin that was successfully reported to exhibit significant urease inhibitory activities. Spectrophotometric method was used in this study with the theory of Beers Law in order to measure the changes in ammonia concentration. Small reduction of ammonia (NH3) concentration with different about 0.1 mol/L was calculated and the releasing was almost equal till the end of incubation time. The guava leaves extract prepared showed the potential to reduce the release of NH3 concentration during urea application.

scholarly journals Chemical composition of the essential oil of Psidium guajava leaves and its toxicity against Sclerotinia sclerotiorum

2018 ◽  
Vol 39 (2) ◽  
pp. 865
Author(s):  
Elizabeth Aparecida Josefi Silva ◽  
Vanessa Paula da Silva ◽  
Cassia Cristina Fernandes Alves ◽  
José Milton Alves ◽  
Edson Luiz Souchie ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Chemical Composition ◽  
Essential Oil ◽  
Sclerotinia Sclerotiorum ◽  
Psidium Guajava ◽  
Gas Chromatography Mass Spectrometry ◽  
Flame Ionization ◽  
Randomized Design ◽  
Dry Seasons ◽  
Guava Leaves

Globally, the fungus Sclerotinia sclerotiorum is considered as one of the most important phytopathogens, since it affects the production of several economically important crops. Further, it is difficult to control, thus increasing the use of pesticides. Therefore, the search for new substances, especially those extracted from plants, has received special attention to control this plant pathogen. The objective of the present study was to evaluate the yield and chemical composition of the essential oil extracted from the fresh leaves of guava collected during the rainy and dry seasons, and also to evaluate its toxicity against S. sclerotiorum. The experiment was a completely randomized design with five treatments and six replicates. The essential oil was extracted by hydrodistillation of the leaves and analyzed by gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. The main compounds identified in the essential oil were trans-caryophyllene and ?-humulene. The essential oil at a concentration of 300 ?L exhibited 90% inhibition of the mycelial growth of S. sclerotiorum. This confirmed the antifungal potential of the essential oil of the guava leaves during both the sampling seasons.

scholarly journals Comparative evaluation of antimicrobial efficacy of an alternative natural agent for disinfection of toothbrushes

2017 ◽  
Vol 11 (01) ◽  
pp. 111-116
Author(s):  
R. Vignesh ◽  
C. Vishnu Rekha ◽  
Parisa Norouzi Baghkomeh ◽  
Sankar Annamalai ◽  
Ditto Sharmin
Keyword(s):  
Lactobacillus Acidophilus ◽  
Comparative Evaluation ◽  
Psidium Guajava ◽  
Control Group ◽  
Microbial Culture ◽  
Aqueous Extracts ◽  
Colony Forming Unit ◽  
Evaluation Group ◽  
Guava Leaves ◽  
Natural Agent

ABSTRACT Objective:The aim of this study was to assess the antimicrobial potency of aqueous extract of Psidium guajava leaves in two different concentrations as a toothbrush disinfectant against three oral bacterial species.Materials and Methods: Aqueous extracts of P. guajava leaves were prepared at 20% and 30% concentrations and 0.2% chlorhexidine was used as control. The toothbrushes were equally divided into 9 groups with 10 toothbrushes per disinfectant, which were contaminated with Streptococcus mutans, Lactobacillus acidophilus, and Enterococcus faecalis. Microbial culture was done after 5 min and 3 h of decontamination.Results: Group Ia and Ib showed that the presence of E. faecalis was observed in 8 (40%) of 20 toothbrushes. Group IIa and IIb showed a significant reduction in colony forming unit/toothbrush during 3 h evaluation. Group IIIa and IIIb showed nil growth during 3 h evaluation. Nil growth was observed with the control group for all three organisms. Statistically significant values were obtained for 5 min (P < 0.001) and 3 h (P < 0.001) disinfection period against L. acidophilus at two different concentrations.Conclusion: Aqueousextracts of guava leaves can be used as an alternative organic product for disinfection of toothbrushes.

scholarly journals Antioxidant and Anti-Diabetic Activities of Polysaccharides from Guava Leaves

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1343 ◽  
Author(s):  
You Luo ◽  
Bin Peng ◽  
Weiqian Wei ◽  
Xiaofei Tian ◽  
Zhenqiang Wu
Keyword(s):  
Antioxidant Activity ◽  
High Fat Diet ◽  
Functional Foods ◽  
Radical Scavenging ◽  
Psidium Guajava ◽  
Diabetic Mice ◽  
Total Antioxidant ◽  
Long Time ◽  
Guava Leaves

Guava (Psidium guajava L., Myrtaceae) leaves have been used as a folk herbal tea to treat diabetes for a long time in Asia and North America. In this study, we isolated polysaccharides from guava leaves (GLP), and evaluated its antioxidant activity in vitro and anti-diabetic effects on diabetic mice induced by streptozotocin combined with high-fat diet. The results indicated that GLP exhibited good DPPH, OH, and ABTS free-radical scavenging abilities, and significantly lowered fasting blood sugar, total cholesterol, total triglycerides, glycated serum protein, creatinine, and malonaldehyde. Meanwhile, it significantly increased the total antioxidant activity and superoxide dismutase (SOD) enzyme activity in diabetic mice, as well as ameliorated the damage of liver, kidney, and pancreas. Thus, polysaccharides from guava leaves could be explored as a potential antioxidant or anti-diabetic agents for functional foods or complementary medicine.

scholarly journals Antibacterial activity of GUAVA, Psidium guajava Linnaeus, leaf extracts on diarrhea-causing enteric bacteria isolated from Seabob shrimp, Xiphopenaeus kroyeri (Heller)

2008 ◽  
Vol 50 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Flávia A. Gonçalves ◽  
Manoel Andrade Neto ◽  
José N. S. Bezerra ◽  
Andrew Macrae ◽  
Oscarina Viana de Sousa ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Antimicrobial Effect ◽  
Enteric Bacteria ◽  
Psidium Guajava ◽  
Salmonella Spp ◽  
Leaf Extracts ◽  
Xiphopenaeus Kroyeri ◽  
Guava Leaves ◽  
Guava Leaf

Guava leaf tea of Psidium guajava Linnaeus is commonly used as a medicine against gastroenteritis and child diarrhea by those who cannot afford or do not have access to antibiotics. This study screened the antimicrobial effect of essential oils and methanol, hexane, ethyl acetate extracts from guava leaves. The extracts were tested against diarrhea-causing bacteria: Staphylococcus aureus, Salmonella spp. and Escherichia coli. Strains that were screened included isolates from seabob shrimp, Xiphopenaeus kroyeri (Heller) and laboratory-type strains. Of the bacteria tested, Staphylococcus aureus strains were most inhibited by the extracts. The methanol extract showed greatest bacterial inhibition. No statistically significant differences were observed between the tested extract concentrations and their effect. The essential oil extract showed inhibitory activity against S. aureus and Salmonella spp. The strains isolated from the shrimp showed some resistance to commercially available antibiotics. These data support the use of guava leaf-made medicines in diarrhea cases where access to commercial antibiotics is restricted. In conclusion, guava leaf extracts and essential oil are very active against S. aureus, thus making up important potential sources of new antimicrobial compounds.

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