Phytochemical Methods Harborne Pdf Free Download ^HOT^
Phytochemical screening of aqueous methanol fraction of Hibsicus asper revealed the presence of phyto-compounds that have been documented to have antioxidant and other activities. Flavonoids have been shown to be highly effective scavengers of most oxidizing molecules, including singlet oxygen, and various free radicals  implicated in several diseases. Flavonoids have anti-oxidative and mucosal protective effect [20, 21]. Flavonoid-rich vegetables are widely used functional foods since they can be used to treat cardiovascular diseases . They are characterized by their good bioavailability and, hence, constant dietary consumption of flavonoids has been reported to give pharmacologically relevant plasma concentrations in humans . In addition, several studies have reported the possible cardioprotective effects of flavonoids against ischemia reperfusion [24, 25]. Saponins may activate mucous membrane protective factors, while tannins reduce the permeability of mucosa to chemical irritation. Consequently, they reduce inflammation, exert astringent and protective action on the stomach mucosa, and curb excess acidity. In addition, terpenoids and alkaloid compounds have also been reported to have potent activity against gastric ulcers [26, 27]. Terpenoids have been reported to relax cardiovascular smooth muscle by inhibition of Ca2+ influx in vascular smooth muscle or via quenching of reactive oxygen species (ROS) and stimulation of nitric oxide (NO) synthesis . The presence of these phytochemicals in methanol fraction of H. asper leaves possibly indicates its numerous medicinal properties such as anti-inflammatory, anti-ulcer, and anti-oxidative properties, among others.
phytochemical methods harborne pdf free download
IR spectra of isolated flavonoid confirms the presence of OH group in free and binding states act as binding site of enzymes due to this isolated flavonoid exhibited anti-carcinogenic activity to the best extent by retarding and modulating the phase I enzymes (cytochrome P450 and b5) peroxidation level, biochemical enzymes (catalase, superoxide dismutase, aspartate transaminase, alanine transaminase, alkaline phosphates, total protein and total cholesterol) altered by N-nitrosodiethylamine (Sharma et al, 2012; Sharma and Pracheta, 2013). Quantitative structure activity relationship (QSAR) is an accepted means for establishing quantitative relationship between biological activity and descriptors representing physicochemical properties of the compounds using statistical methods (Kiralji and Ferreira, 2009) and it helps to precisely predict the biological activities of newly designed analogues (de Melo et al., 2010). Successful prediction of anti-HIV (Alves et al., 2001) and anti-tumor activities (Moriani et al., 2002) of flavonoid compounds have been reported. According to these studies, the antioxidant activity of flavonoids depends strongly on the number and position of hydroxyl groups in the molecule. In the present findings dihydroxylated B-ring (catechol structure), presence of hydroxyl and methoxy functional groups and in the C-ring presence of
This was proved that flavonoids scavenge free radicals and reactive oxygen species and also inhibit lipid peroxidation. The pharmacological curative effects of EN leaf consumption is due to the presence of its phytochemicals including flavonoids, which have antioxidant properties. Our results depicts that the fractions of EN contains flavonoids in a bulky amount, and be important in inhibiting oxidative stress mechanisms that lead to degenerative diseases because by lipid peroxidation products and reactive oxygen species. We are currently focusing our research on the study of in vivo anticarcinogenic activities of isolated flavonoid 2-(3,4-dihydroxy-5-methoxy-phenyl)-3,5-dihydroxy-6,7-dimethoxychromen-4-one which is described further.
The methods described by Harborne  with minor modifications as described previously  were used to test for the presence of the active ingredients in the test sample. The phytochemicals tested were tannins, alkaloids, flavonoids, terpenes, saponins, carbohydrates and cyanogenetic glycosides.
In agar diffusion assays, the inhibitory zone diameter produced is the result of the growth of the test organisms and the diffusion of the test agents through the agar, both events occurring simultaneously  so it then means that any factor which affects the rate of microbial growth or rate of diffusion of the suspected antimicrobial agent under test, will invariably affect the result. The factors which were pertinent to the formation of inhibition zone included the type/nature of the test organisms, the size of inoculum, the culture media (which should be able to support the growth of organisms and not interfere with diffusion or activity of test organisms) and the temperature of incubation . Secondary metabolites of plants such as saponins, flavonoids, tannins, carbohydrates, cyanogenetic glycosides, reducing sugar and all other active principles of plants have been shown to be responsible for the antimicrobial activities shown by these extracts. [17, 2]. However from the phytochemical analysis of this plant extract, some of these secondary metabolites were absent (tannins, anthroquinone and flavonoid), some in low and moderate concentrations and a few in high concentration. However, the antimicrobial activities shown by the extract will likely be due to one or more of the several other phytochemical constituents shown to be present in the extract (Table 1). There was no activity against E. coli for both the typed culture and the clinical isolate, as opposed to information in literature . This may be due to the absence of some secondary metabolites or the presence of some in low concentration; or it may be due to the type of strains used or a slight change in any of the factors mentioned earlier that are likely to affect rate of microbial growth or rate of diffusion of the test agent. A percentage change in the inhibition zone diameter was used to draw inference on the effects of the interaction on the test organisms. It has been suggested that for a synergistic effect, the diameter of the zone of inhibition in the test plate (plate containing the plant extract and the antibiotics) should be greater than that in the control plate (plate containing extract-free base agar layer) by at least 19%. A percentage increase in the inhibition zone diameter that is lower than 19% indicates additivity. Where the inhibition zone diameters in the test and the control are equal, the combined antibiotics have indifferent effect and if the zone diameter in the test is less than the one in the control, then there is antagonism . It was also observed that for S. aureus it was only ampicillin that did not show activity against it. This may be due to the fact that S. aureus usually develops resistance to β-lactam drugs. There was antagonism in inhibitory zone diameter when streptomycin was combined with the extract. Septrin and ciprofloxacin showed indifferent effects individually when they were combined with the extract. For P. mirabilis, all the test antibiotics showed activity. However when combined with the plant extract, it was observed that streptomycin showed antagonism. Ciprofloxacin and ampicillin were synergistic when each was combined with the extract. However with septrin, there was additivity. Against P. aeruginosa all test antibiotics showed activity, but on combining with the plant extract, ciprofloxacin showed synergism while septrin was antagonistic. Ampicillin and streptomycin did not have any individual activity when combined with the extract. The antibiotics were all active against the clinical isolate of E. coli and the typed culture, when the extract was combined with either ciprofloxacin or septrin, synergistic interaction was observed. Moreover, ampicillin and septrin when combined together with either ciprofloxacin or septrin showed synergistic interaction. Moreover, ampicilin and streptomycin when combined separately with the extract showed antagonism against E. coli (ATCC 11755). Against the clinical isolate of E. coli ciprofloxacin was additive, streptomycin was antagonistic while septrin and ampicillin were synergistic. Nakamura et al  found that the essential oil of O. gratissimum has antibacterial activity against Shigella flexineri, E. coli, Klebsiella spp and Proteus mirabilis. Ketoconazole and nystatin were both active against the clinical isolate of C. albicans and the type culture. The effect of interaction between the plant extract and the antibiotics was synergistic on C. albicans. Against C. albicans (ATCC 90028), ketoconazole showed antagonism while nystatin was additive. In a previous study, using agar dilution technique, Silva et al  demonstrated that O. gratissimum exhibited antifungal activities against the dermatophytes: M. canis, M. gypseum, T. rubrum and T. mentagrophytes. Lemos and co-workers  also showed that the ethanolic crude extract and the ethyl acetate, hexane, chloroform, essential oil and eugenol of O. gratissimum have antifungal activities against C. neoformans. Generally, it should be remembered that the study is in vitro, and the likelihood of possibility of change in activity of microflora of a patient cannot be ruled out as it functions in vivo. Also, the possibility of alteration of the presence of other exogenous compound and the significance of this alteration in modifying drug interaction will only be determined by detailed pharmacokinetic studies that relate to the distribution of drugs metabolized by the microflora and their potentially active metabolites to the therapeutic response of the patient to the antibiotic. 350c69d7ab