With the increasing interest on natural products discovery, utilization of plant parts which are commonly disregarded is another breakthrough. This study sought to determine the secondary metabolites present, phenolic contents, radical scavenging activities and antibacterial properties of 10 selected ornamental flowers which were Adenium obesum, Allamanda cathartica, Bougainvillea glabra, Catharanthus roseus, Caesalpinia pulcherrima, Heliconia subulata, Ixora coccinea, Mussaenda philippica, Tecoma stans and Torenia fournieri, from Nueva Vizcaya, Philippines. The ethanolic crude extracts were subjected to thin layer chromatography (TLC) phytochemical screening. Total phenolics expressed as mg AAE/g sample were determined through Folin-Ciocalteu method. Radical scavenging activities were measured using DPPH assay. Antibacterial activities were assessed through TLC bioautography. To quantify bacterial susceptibility of C. pulcherrima, MIC and MBC were employed in the ethyl acetate sub-fraction. TLC showed different types of phenolics, alkaloids, essential oils and terpenes. T. fournieri showed the highest total phenolics with 155 mg AAE/g while H. subulatahad showed the lowest with 3.50 mg AAE/g. Measurement of IC50 showed that H. subulata had the highest antioxidant activity followed by T. fournieri with 303 ppm and 320 ppm, respectively. H. subulata having the least amount of total phenolics had greatest radical scavenging activity. This indicates that other than phenolics, other metabolites can pose great antioxidant activities. The antibacterial testing showed that M. philippica, I. coccinea, H. subulata, C. pulcherrima and A. cathartica were bioactive against Staphylococcus aureus and Escherichia coli. MIC and MBC of C. pulcherrima ethyl acetate sub-fraction is within the range of 2.5-10 mg/mL.

Determination of the Antioxidant, Phytochemical and Antibacterial Profiles of Flowers from Selected Ornamental Plants in Nueva Vizcaya, Philippines

In the present study, Ethyl acetate extract of mature but not fully ripe fruit rinds of Garcinia indica and rhizomes of Curcuma aromatica were investigated for antibacterial activity against Xanthomonas campestris and Xanthomonas axonopodis pv. punicae by direct bioautography technique. The bioautography directly provides information about antimicrobial activity of substances separated from a mixture. The bioautography results revealed that, the Zone of inhibition for extract of fruit rinds of G. indica was observed at Rf 0.63 and for extract of rhizomes of C. aromatica zones of inhibition were observed at Rf 0.73 and 0.93. This indicates that the compounds retained at these Rf values have potent antibacterial activity. These compounds were isolated and identified using LC-MS/MS and GC-MS techniques.

Isolation and Identification of Antibacterial Compounds from the Extracts of Garcinia indica and Curcuma aromatica, using Bioautography and Mass Spectrometric Techniques

Ottonia martianaMiq. (Piperaceae), a plant known popularly in southern Brazil as “anestesia” and used in the treatment of odontalgia for its anesthetic action on the oral mucosa, was investigated for antibacterial activity by paper disc agar diffusion and bioautographic methods, against microorganisms present in the human oral cavity [Streptococcus mutans(ATCC 25175), Streptococcus mitis (ATCC 49456), Streptococcus pyogenes (ATCC 19615), Streptococcus salivarius (ATCC 25975), Escherichia coli (ATCC 11229 and 25922), Pseudomonas aeruginosa(ATCC 27853) and Enterobacter aerogenes (ATCC 27853).The crude extract of O. martiana(32.9 mg mL -1 ) had antibacterial potential against all Gram-positive bacteria tested. Analysis of the bioautograms led to the detection of bioactive substances,among which it was possible to identify piperovatine (Rf 0.35), piperlonguminine (Rf 0.52) and isopiperlonguminine (Rf 0.52). The piperovatine and isopiperlonguminine were isolated from the roots of O. martiana,guided by a bioautographic antibacterial bioassay. Keywords: Amides. Antibacterial activity. Bioautography. Toothache. Ottonia martiana.

 RESUMO Bioautografia para avaliacao da atividade antibacteriana da Ottonia martiana Miq. (Piperaceae) sobre a microbiota oral humana Ottonia martianaMiq. (Piperaceae), planta conhecida popularmente por “anestesia” e empregada no tratamento de odontalgias devido a sua acao anestesica sobre a mucosa oral, foi investigada por meio de ensaios antibacterianos de difusao em disco de papel e de bioautografia frente a microorganismos presentes na microbiota oral humana [Streptococcus mutans(ATCC 25175), Streptococcus mitis (ATCC 49456), Streptococcus pyogenes (ATCC 19615), Streptococcus salivarius (ATCC 25975), Escherichia coli (ATCC 11229 e 25922), Pseudomonas aeruginosa(ATCC 27853), Enterobacter aerogenes (ATCC 27853). Os resultados dos bioensaios mostraram que o extrato bruto de O. martiana(32.9 mg mL-1 ) apresenta potencial antibacteriano frente as bacterias Gram-positivas testadas. Dentre as substâncias bioativas detectadas foram identificadas a piperovatina (Rf 0.35), piperlonguminina (Rf 0.52) e a isopiperlonguminina (Rf 0.52). A piperovatina e isopiperlonguminina foram isoladadas do extrato das raizes de O. martiana, guiadas pelo teste de bioautografia. Palavras-Chave: Amidas. Atividade antibacteriana. Bioautografia. Odontalgia. Ottonia martiana.

Cristina Petz de Lima

Papers

Bioautography to assess antibacterial activity of Ottonia martiana Miq. (Piperaceae) on the human oral microbiota