RESUMEN
Marine debris comprising single-use plastic products (SUPs) is ubiquitous in Asian coastal waters, but there is little information on the types of polymers and the concentrations of plastic additives such waste products contain. In this study, 413 SUPs randomly collected from 4 Asian countries between 2020 and 2021 were analyzed to obtain specific polymer and organic additive profiles. Polyethylene (PE), coupled with external polymers, was prominent in the inside of the SUPs, whereas polypropylene (PP) and polyethylene terephthalate (PET) were prevalent in both the insides and outsides of the SUPs. The use of different polymers in the insides and outsides of PE SUPs implies specific and complicated recycling systems are required to maintain the purity of the products. Phthalate plasticizers including dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), and the antioxidant butylated hydroxytoluene (BHT) were prevalent in the SUPs (n = 68). High concentrations of DEHP were detected in PE bags from Myanmar (820,000 ng/g) and Indonesia (420,000 ng/g), which were an order of magnitude greater than the concentrations in PE bags collected in Japan. SUPs containing high concentrations of organic additives may be the primary source of harmful chemicals in the environment, and should be responsible for their ubiquitous distribution in ecosystems.
Asunto(s)
Dietilhexil Ftalato , Ácidos Ftálicos , Polímeros , Japón , Indonesia , Mianmar , Tailandia , Ecosistema , Plásticos , Dibutil Ftalato , PolietilenoRESUMEN
A series of sixteen A-ring modified (2,3-indolo-, 2-benzylidene) oleanonic acid derivatives, holding some cyclic amines, linear polyamines and benzylaminocarboxamides at C28, has been synthesized and screened for antiviral activity against influenza A/PuertoRico/8/34 (H1N1) and Dengue virus serotypes of DENV-1, -2, -3, -4. It was found that 28-homopiperazine 2 and 3-N-phthalyl 22 amides of oleanonic acid demonstrated high potency with selectivity index SI 27 (IC50 21 µM) and 42 (IC50 12 µM). Oleanonic acid aminoethylpiperazine amide 6 and C-azepano-erythrodiol 23 appeared to be the most effective compounds against DENV-1 (IC50's 67 and 107 µM) and -2 (IC50's 86 and 68 µM correspondingly) serotypes.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Triterpenos , Humanos , Poliaminas/farmacología , Poliaminas/uso terapéutico , Gripe Humana/tratamiento farmacológico , Triterpenos/uso terapéutico , Antivirales/uso terapéutico , Amidas/uso terapéuticoRESUMEN
A series of lupane-, oleanane- and dammarane-based triterpenoids with 3ß-amino, A-ring azepano- and 3,4-seco-fragments has been synthesized and evaluated for antiviral activity against influenza A(H1N1) virus. It was found that azepanodipterocarpol 8 and 3ß-amino-28-oxoallobetulin 11 showed antiviral activity with IC50 1.1 and 2.6 µg ml-1, and selectivity index of 19 and 10, respectively.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Triterpenos , Antivirales/farmacología , Humanos , Gripe Humana/tratamiento farmacológico , Ácido Oleanólico/análogos & derivados , Triterpenos/farmacología , DamaranosRESUMEN
AIM OF THE STUDY: For identification of the active constituents we investigated the anticancer activity of cardenolides from Streptocaulon tomentosum Wight & Arn. (Asclepiadaceae) and from Nerium oleander L. (Apocynaceae) which are both used against cancer in the traditional medicine in their region of origin. MATERIAL, METHODS AND RESULTS: The antiproliferative activity of cardenolides isolated from roots of Streptocaulon tomentosum (IC(50)<1-15.3 µM after 2 days in MCF7) and of cardenolide containing fractions from the cold aqueous extract of Nerium oleander leaves ("Breastin", mean IC(50) 0.85 µg/ml in a panel of 36 human tumor cell lines), their influence on the cellular viability and on the cell cycle (block at the G2/M-phase or at the S-phase in tumor cells, respectively) were determined using different cell lines. The murine cell line L929 and normal non-tumor cells were not affected. Bioactivity guided fractionation of Breastin resulted in the isolation of the monoglycosidic cardenolides oleandrine, oleandrigeninsarmentoside, neritaloside, odoroside H, and odoroside A (IC(50)-values between 0.010 and 0.071 µg/ml). CONCLUSIONS: The observed anticancer activities of extracts and isolated cardenolides are in agreement with the ethnomedicinal use of Streptocaulon tomentosum and Nerium oleander. The most active anticancer compounds from both species are monoglycosidic cardenolides possessing the 3ß,14ß-dihydroxy-5ß-card-20(22)-enolide structure with or without an acetoxy group at C-16. The results indicate that the cytotoxic effects are induced by the inhibition of the plasma membrane bound Na(+)/K(+)-ATPase.