In vitro leaves and twigs antimicrobial properties of Psidium guajava L. (Myrtaceae)

Abstract

The complex [Cu(en) 2 (H 2 O)](sy) 2 (en)(H 2 O) 2 has been synthesized and characterized by its electronic and vibrational spectra. The molecular structure of the complex has been determined by X-ray diffraction methods. The complex crystallizes in the orthorhombic space group Pnma with unit-cell parameters a = 10.7236 (5), b = 20.4660(10), c = 14.4523(11)Å and Z = 4. In the cation, the Cu(II) ion has a distorted square pyramidal coordination with two bidendate (en) ligands forming the basal plane and a H 2 O molecule in the apical position. The complex cations and syringate anions constitute chains along the b axis in -A-B-A-fashion. The members of the chains are linked by through N-H···O hydrogen bonds. The (en) molecules are responsible for connecting adjacent layers.

Antibacterial Activity Evaluation of Psidium guajava L. (Myrtaceae) Crude Extracts Against Selected Bacterial Pathogens

“…While, for bacterial isolates, LE ethyl acetate exhibited the highest A.I against S. pneumoniae (1.7), followed by LE hot water (1.6) and TE <1 cm (1.6) against the same isolate. Our data were in coherent with findings of Saleh et al (2015), who…”

“…In this respect, for bacteria ZI at 30% ranged between 12 mm (E. coli) and 14.5 mm (P. aeruginosa); while this value at the same tannins concentration varied between 9 mm (C. albicans) and 9.5 mm (A. niger) for fungal pathogens. Saleh et al (2015) reported antimicrobial effects of methanol, ethanol, acetone, ethyl acetate and hot water (leaves and twigs fractions) P. guajava L. crude extracts against three bacterial and two fungal pathogens. they reported that hot water twigs < 1 cm diameter extract displayed the highest ZI of 20 mm with hot water twigs < 1 cm against C. albicans fungi.…”

“…Previously, Egharevba et al (2010) reported lower values for this parameter (0, 0.63, 0.63 and 0) using 70% methanol, methanol, erythromycin and hexane P. guajava LE against C. albicans. Whereas, Saleh et al (2015) reported that hot water TE <1 cm exhibited the highest A.I against C. albicans fungi (2). While, for bacterial isolates, LE ethyl acetate exhibited the highest A.I against S. pneumoniae (1.7), followed by LE hot water (1.6) and TE <1 cm (1.6) against the same isolate.…”

“…While, it was ranged between 0.125-> 0.250 mg/mL and between 0.062-> 0.250 mg/mL against the tested isolate with aqueous and methanolic extracts, respectively against 8 S. aureus (MRSA) isolates with P. guajava stem bark aqueous and methanolic extracts (Esimone et al, 2012). Whereas, Saleh et al (2015) reported that the estimated MIC values varied between 4 and 7.2 mg/mL for bacterial, whereas, it ranged between 14.5 and 37.3 mg/mL for fungal isolates. While, ethyl acetate had the lowest antimicrobial activity compared to the other tested solvents.…”

“…Determination of MIC by the microdilution broth method was carried out according to NCCLS approved standards. Microdilution broth susceptibility assay was used (Saleh et al, 2015). Three replicates of serial dilutions of extract (100 mg/mL) or of antibiotic (128 µg/mL) were prepared in TSB medium in 96-well microtiter plates.…”