469 research outputs found
Naturally Occurring Anthracyclines
No full textThe present article gives an overview of the natural occurring anthracyclines and anthracyclinones reported from microorganisms. A general description, discussion of their physicochemical properties, including NMR increments, and their structural classification are reported. In addition to a compilation of their sugar moieties, an exhaustive list of naturally occurring anthracyclines and anthracyclinones has been added
Triterpenoids, essential oil and photo-oxidative 28 → 13-lactonization of oleanolic acid from Lantana camara
No full textTwo novel triterpenoids have been isolated from the roots of Lantana camara L.: 3 beta,19 alpha dihydroxy ursan-28-oic acid and 21,22 beta- epoxy-3 beta-hydroxy olean-12-en-28-oic acid in its methyl ester form. Its leaves have yielded an essential oil which is rich in sesquiterpenes. Oleanolic acid, which is thought to be a hepatoprotective compound, was isolated from L. camara roots and converted into its 28 --> 13 beta lactone by a facile photo-oxidation reaction. (C) 2000 Elsevier Science Ltd. All rights reserved
19 beta -> 28-lactonization of pomonic acid from Lantana camara roots
No full textLantana camara L. var. aculeata yielded a triterpenoid, pomonic acid (1). The acid-catalyzed lactonization of this gamma-hydroxy acid afforded a rearranged lactone 3, the structure of which was assigned by detailed 2D-NMR studies. A reaction mechanism involving a 1,3-butadiene intermediate is proposed
FLAVONOIDS FROM SUDANESE ALBIZIA ZYGIA (LEGUMINOSAE, SUBFAMILY MIMOSOIDEAE), A PLANT WITH ANTIMALARIAL POTENCY
No full textThree flavonoids were isolated for the first time from the Sudanese medicinal plants Albizia zygia. Compounds 1-3 were identified by interpretation of ESI mass data, (1)H, (13)C and 2D NMR as well as by comparison with published data as 4',7-dihydroxyflavanone (1) 3',4',7-trihydroxyflavone (2), 3-O-methylfisetin (3',4',7-trihydroxy-3-methoxyflavone, 3). All flavonoids were tested against Plasmodium falciparum, and only compound 2 showed high antimalarial activity (IC(50) 0.078 mu g/ml).German Academic Exchange Service (DAAD
Fujianmycin C, A Bioactive Angucyclinone from a Marine Derived Streptomyces sp. B6219 [1]
No full textFrom a marine-derived streptomycete, a new bioactive angucyclinone, fujianmycin C (1), has been isolated along with five known, metabolites fujianmycins A (2) and B (3), ochromycinone (4), ochromycinone methyl ether (5), and tetrangulol methyl ether (6). The structure elucidation of fujianmycin C (1) was performed by detailed analysis of data such as (1)H, (13)C, (1)H, (1)H COSY, HSQC, HMBC and NOESY spectra. Fujianmycin C (1) exhibited antibacterial activity against Streptomyces viridochromogenes (Tu57).German Academic Exchange Services (DAAD
Himalomycin A and B: Isolation and structure elucidation of new fridamycin type antibiotics from a marine Streptomyces isolate
No full textAn acetoxygenated analogue of ergosterol from a soft coral of the genus Lobophytum
No full textChemical investigation of a soft coral of the genus Lobophytum of the Andaman and Nicobar coasts resulted in the isolation of a new marine sterol acetate, (24S)-ergostane-3beta,5alpha,6beta,25-tetraol-3,6,25-triacetate (1) and of two known sterol glycosides 3beta,4alpha-dihydroxypregn-20-ene-4-O-beta-D-arabinopyranoside and 24-methylenecholest-5-ene-3beta,7beta,16beta-triol-3-O-alpha-L-fucopyranoside-7beta-acetate. The structures of the compounds were elucidated based on spectral studies and chemical conversions
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