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Three Echeveria species from Sinaloa, Mexico (Echeveria craigiana, Echeveria kimnachii and Echeveria subrigida) were analyzed for their content of antioxidant compounds (β-carotene, ascorbic acid, α-tocopherol, total phenolics and flavonoids) and the in vitro antioxidant (DPPH, ABTS, ORAC and β-carotene bleaching [β-CBM]), α-glucosidase inhibitory and antibacterial activities. The studied Echeveria species showed high α-tocopherol content (2.9–9.0 mg/100 g f.w.) and total phenolics as Gallic Acid Equivalents (GAE) (152.2–400.5 mg GAE/100 g f.w.). Antioxidant activities of the three Echeveria methanol extracts (ME) were higher than those of other well-known plants with this property; the activities of E. craigiana (ABTS, 65.91 μmol ET/g f.w.) and E. subrigida (β-CBM, 79.3%) were remarkable. The Echeveria ME showed stronger α-glucosidase inhibition (IC 50 25.21–50.57 μg/mL) than acarbose (IC 50 3.59 mg/mL) as well as high antibacterial activity (Minimal Inhibitory Concentrations, MICs ⩽ 1 mg/mL), mainly against Gram positive bacteria. The results showed the three Echeveria species had components/biological activities with high potential for food/pharmacological uses and could be exploited by sustainable management schemes. [ABSTRACT FROM AUTHOR]

Abstract: The fruit of Vitex mollis Kunth contains water‐soluble melanin (SM), whose properties have been poorly described. This study determined physicochemical characteristics, the inhibition of carbohydrate digestive enzymes (amylase and α‐glucosidase), and antioxidant activity (ABTS, DPPH, ORAC, and β‐carotene bleaching) of SM (partially purified, aqueous extraction), water‐insoluble melanin (IM) (pure, alkali‐acid extraction), and organic (i.e., methanol, ethanol, and methanol : water 8:2 vol/vol) and aqueous extracts of V. mollis fruit. SM and IM were characterized by UV and IR spectroscopy, and their spectra showed signals characteristic of melanins. They also showed similar antioxidant (1,321–2,664 μmol TE/g), and α‐glucosidase inhibitory (IC50 1.48–0.022 mg/mL) activities, values that were better than those of the organic extracts (ABTS < 746 µmol TE/g and IC50 > 4.87 mg/mL, respectively). In addition, SMs showed higher extraction yields than IMs. Therefore, SM shares nutraceutical properties with IM and can be obtained by simple and environmentally friendly methods. Practical applications: Melanins show biological activities (e.g., antioxidant, immunostimulatory, UV‐, and radiation‐protective) and their consumption has been associated with health benefits. However, studies of plant melanins are scarce because their extraction involves harsh pH conditions and the yields are usually low. The results showed that melanin was the main pigment in Vitex mollis fruit and water‐soluble. Moreover, the extraction method was simple, ecological, and produced high yields. Both water‐soluble and water‐insoluble melanins showed similar biological activities (antioxidant and α glucosidase inhibition). Species of Vitex are commonly employed as food and in folk medicine (e.g., premenstrual and gynecological disorders, gastrointestinal problems and inflammation, bacterial infections). Soluble melanins of V. mollis could be used as food supplement or in pharmaceutical preparations. [ABSTRACT FROM AUTHOR]

Context:Helicteres vegaeCristóbal (Sterculiaceae) (Hv) andHeliopsis sinaloensisB.L. Turner (Asteraceae) (Hs) are endangered and poorly studied plant species; related plants have been used against chronic-degenerative and infectious diseases. Therefore, Hv and Hs could be sources of bioactive compounds against these illnesses. Objective:To determine the chemical composition and biological activities (antioxidant, antimutagenic and antimicrobial) of Hv and Hs leaves (L) and stems (S). Materials and methods:Methanol extracts (ME) of each plant/tissue were evaluated for their phytochemicals; phenolics (HPLC-DAD-ESI-MS); antioxidant activity (AA) (0.125–4 mg/mL) (DPPH, ABTS, ORAC and β-carotene discoloration); antimutagenicity (0.5 and 1 mg/plate) (Ames assay, tester strainSalmonella entericaserovar Typhimurium YG1024, 1-nitropyrene as mutagen); activity against human pathogens (1 mg/mL); and toxicity (0.01–2 mg/mL) (Artemia salinaassay). Results:All ME showed flavonoids and triterpenes/steroids. The ME-SHv had the highest content of total phenolics (TP) (2245.82 ± 21.45 mg GAE/100 g d.w.) and condensed tannins (603.71 ± 1.115 mg CE/100 g d.w.). The compounds identified were flavonoids (kaempferol 7-O-coumaroylhexoside, and two kaempferol 7-O-rhamnosylhexosides) and phenolics [rosmarinic acid, and 3′-O-(8″-Z-caffeoyl) rosmarinic acid]. The ME-LHs showed the highest content of flavonoids (357.88 mg RE/g d.w.) and phenolic acids (238.58 mg CAE/g d.w.) by HPLC. The ME-SHv showed the highest AA. All ME were strong antimutagens (63.3-85.7%). Only the Hs extracts were toxic (ME-LHs, LC50 = 94.9 ± 1.7 μg/mL; ME-SHs, LC50 = 89.03 ± 4.42 μg/mL). Discussion and conclusions:Both Hv and Hs are potential sources of preventive and therapeutic agents against chronic-degenerative diseases. [ABSTRACT FROM PUBLISHER]