16 research outputs found
A cascade synthetic route to new bioactive spiroindolinepyrido[1,2-a]indolediones from indirubin
Constituents of the Indonesian Epiphytic Medicinal Plant Drynaria rigidula
The rhizome of Drynaria rigidula has been traditionally claimed to have anti-infective properties. A phytochemical study conducted on the rhizome successfully isolated two new aromatic glycosides as well as three known terpenoids, two benzoic acid derivatives and two known flavonoid glycosides. The rhizome methanol extract and its fractions were tested against Mycobacterium tuberculosis, Plasmodium falciparum, herpes simplex virus and KB-oral cancer cell; insignificant activity was found
Alkaloids from the root of Indonesian Annona muricata L
Annona muricata L. has been used traditionally in Indonesia to treat disease. Phytochemical studies on the alkaloid fractions from the root of Annona muricata L. from Malang-Indonesia resulted in the isolation of an unreported benzylisoquinoline alkaloid (+)-xylopine 5 as well as four known alkaloids (1-4). The crude methanol extract and alkaloid fractions were tested against Plasmodium falciparum K1 and against bacteria (Escherichia coli, Klebsiella pneumonia, Acinetobacter buamanii, Pseudomonas aeruginosa, Methicillin-resistant Staphylococcus aureus) with insignificant activities (MIC \u3e 32 µg/mL). Individual alkaloids were tested against a human suspension cancer cell line (HL-60 leukemia cells) and two human fibroblastic cancer cell lines (A549 lung cancer cells and HepG2 liver cancer cells) in which compound 5 was the most toxic alkaloid with IC50 values ranging from 20 to 80 µM
Rapid cascade synthesis of poly-heterocyclic architectures from indigo
The base-induced propargylation of the dye indigo results in the rapid and unprecedented one-pot synthesis of highly functionalized representatives of the pyrazino[1,2-a:4,3-a′]diindole, pyrido[1,2-a:3,4-b′]diindole and benzo[b]indolo[1,2-h]naphthyridine heterocyclic systems, with the last two reflecting the core skeleton of the anticancer/antiplasmodial marine natural products fascaplysin and homofascaplysins and a ring B-homologue, respectively. The polycyclic compounds 6–8, whose structures were confirmed through single-crystal X-ray crystallographic analysis, arise from sequential inter/intramolecular substitution–addition reactions, and in some cases, ring rearrangement reactions. Preliminary studies on controlling the reaction path selectivity, and the potential reaction mechanisms, are also described. Initial biological activity studies with these new heterocyclic derivatives indicated promising in vitro antiplasmodial activity as well as good anticancer activity. The chemistry described is new for the indigo moiety and cascade reactions from this readily available and cheap starting material should be more broadly applicable in the synthesis of additional new heterocyclic systems difficult to access by other means
Bioactive glycosides from the African medicinal plant Boerhavia erecta L.
Phytochemical studies of the previously unexplored stem of Boerhavia erecta from Burkina Faso, resulted in the isolation of an unreported glycoside 4, 2,3-dihydroxypropylbenzoate-3-O-β-[4″-methoxy] glucuronide as well as seven known glycosides (1-3, 5-8). The major isolate 5 and 8 indicated a significant inhibition against HIV integrase (IC50 10 and 22 μg/mL, respectively). The extracts and isolates were also tested for anti-malarial activity, but insignificant activity was observed
Is mri suitable to study the central effect of gonadal steroids during the oestrus cycle in ewes ?
Phytochemical studies performed on 4 Indonesian epiphytic medicinal plants, Drynaria rigidula L., Hydnophytum formicarum
Jack, Usnea misaminensis (Vain) Motyka, and Calymperes schmidtii Broth., revealed 11 known secondary metabolites (1-11),
reported from these species for the first time. The methanol extracts and their fractions were screened against infective
agents and cancer cells. The dichloromethane fractions of H. formicarum, U. misaminensis, and C. schmidtii showed activity
against lung cancer cells with IC50 values of 35, 11, and 20 µg/mL, respectively
The Human factor
The allylation of indirubin produced the expected indolic N′-allylindirubin and N,N′-diallylindirubin derivatives in moderate yields, together with the corresponding N-substituted isatin products. At higher temperatures, the base-initiated reaction with allylic halides yielded spiroindolinepyrido[1,2-a]indolediones in a one-pot cascade reaction sequence with yields of up to 70%. These readily accessed, new spiro compounds represent the first reported examples of indirubin participating in cascade reactions. Preliminary in vitro biological testing of some of the products indicated promising activity against some cancer cell lines and against Plasmodium falciparum for two spiro derivatives. Computational methods were used to gain a greater understanding of the UV/Vis spectroscopic data for the N′-substituted and N,N′-disubstituted indirubin derivatives