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The fruits of Pilosocereus arrabidae (Cactaceae) is found in the Grumari shoal, located in the Rio de Janeiro state, Brazil and, several studies have already highlighted the importance of consuming its fruits. This work aims to investigate the physical, mineral and physicochemical properties of its fruits as well as to establish the knowledge about their chemical constituents and antioxidant properties. The peel (Pe) and pulp (Pu) extracts were obtained by maceration with the following solvents: hexane (HX), dichloromethane (DCL), ethyl acetate (EAC) and ethanol 70% (ET). The extracts were analyzed by Gas Chromatography coupled to Mass Spectrometry (GC–MS) and, by High Performance Liquid Chromatography (HPLC–DAD and HPLC–MS) for its chemical investigation. For the antioxidant activity investigations the ORAC, DPPH and ferrous ion chelating capacity (FICC) tests were performed. As results, we found higher yields for peels (72%) compared to pulps (28%). By the physical–chemical analyses we point out the fruits as a good source of fiber (pulp: 6.01 mg/100 g; peel: 8.02 mg/100 g). The minerals were analyzed by the method of issuing flames and indicated high levels of selenium (DRI for pulp and peel: 147%) and manganese (DRI pulp: 97.69% and DRI peel: 269.56%). The total flavonoid contents of the fruits performed by HPLC–DAD presented 0.45 μg equiv. in quercetin/mL of peel EAC extract and 0.25 μg equiv. in rutin/mL of pulp EAC extract. The antioxidant activities by the ORAC, FICC and DPPH methods indicated that the ET extracts showed antioxidant activities above the standards adopted for the tests. Among these, we highlight the ET extract of the pulp with EC 50 of 17.57 ± 0.27 μg/mL, lower than Ginkgo biloba EGB761® (23.40 ± 0.04 mg/mL). By the FICC test the EAC extract of the peel and pulp showed 70.0% and 53.4% activity, respectively, at 500 mg/mL, higher than the standard quercetin (50.0%). By the HPLC–DAD and HPLC–MS methods there were detected, for the first time on this species, the presence of the following flavonoids on the EAC extracts: quercetin, rutin, catechin, dihydrokaempferol, quercetin 3 or 4′-O-glucoside, kaempferol and isorhamnetin. By the GC–MS analysis there were detected on the DCL extracts saturated fatty acids (palmitic and stearic) and, on the HX extracts, methylated sugars (peel) and menthol (pulp). To sum up, the fruits of P. arrabidae display antioxidant potential correlated to flavonoid presence, and, high levels of selenium, manganese and fibers, characteristics that can promote beneficial effects on human health.

The chemical composition of volatile compounds in leaves of Mandevilla guanabarica from three restingas in Rio de Janeiro was characterized by GC/MS after SDE. The volatiles common were 3-hexen-1-ol, β-caryophyllene and germacrene D, which were majority compounds for plants from Grumari, Jurubatiba and Marica, respectively. M. guanabarica also contained other compounds: α-cubebene, α-copaene and cubebene (Grumari); β-ocimene, α-caryophyllene and germacrene B (Jurubatiba); and β-elemene and alloaromadendrene (Marica). Although some compounds were common to all locations, the qualitative and quantitative chemical profiles of volatile compounds of M. guanabarica from three different areas in the same season, with similar conditions of temperature and precipitation, were distinct. Leaf histochemical analysis revealed the presence of fatty acids in idioblasts, and rubber grains and droplets of lipophilic substances in the mesophyll, for all three samples. These results indicate the possible influence of physiological variations and/or environmental conditions on the composition of volatiles in M. guanabarica .