2524-37-0Relevant articles and documents
THE INCORPORATION OF 3-HYDROXY-3-METHYLGLUTARIC ACID INTO THE LACTONE RING OF DIOSCORINE IN DIOSCOREA HISPIDA
Leete, Edward,Michelson, Robert H.
, p. 3325 - 3330 (1989)
- and -3-Hydroxy-3-methylglutaric acid were administered to Dioscorea hispida plants, resulting in formation of labelled dioscorine (0.2 percent absolute incorporation).A chemical degradation indicated that there was a non-random incorporation of (14)C into the lactone ring of the alkaloid, the major part of the radioactivity being at its C-10 position.This specific labelling was confirmed by examination of the 13C NMR spectrum of the enriched dioscorine derived from the (13)C2-labelled precursor.There was some scrambling of label, presumably due to catabolism of the 3-hydroxy-3-methylglutaric acid to acetyl-coenzyme A followed by recycling of this intermediate.However the most significant satellites in the 13C NMR spectrum were those arising from contiguous (13)C atoms at C-10 and C-13 of the dioscorine.Ethyl orcellinate failed to serve as a significant precursor of dioscorine.These results indicate that 3-hydroxy-3-methylglutaric acid, or more likely its mono coenzyme A ester, is an intermediate between acetate and the branched eight-carbon unit required for the biosynthesis of dioscorine.Key Word Index - Dioscorea hispida; Dioscoreaceae; dioscorine; alkaloid biosynthesis; 3-hydroxy-3-methylglutaric acid; 13C NMR spectroscopy.
Radical-scavenging activity of orsellinates
Lopes, Thiago Inacio Barros,Coelho, Roberta Gomes,Yoshida, Nidia Cristiane,Honda, Neli Kika
, p. 1551 - 1554 (2008)
Lichens are an important source of phenolic compounds and have been intensively investigated for their biological and pharmacological activities. Lecanoric acid (1), a lichen depside, was isolated from a Parmotrema tinctorum specimen and treated with alcohols to produce orsellinic acid (2) and orsellinates (3) to (9) (2,4-dihydroxy-6-n-methyl benzoates). Free radical scavenging activity of methyl (3), ethyl (4), n-propyl (5), n-butyl (6), iso-propyl (7), sec-butyl (8), tert-butyl (9) orsellinates was evaluated using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) method. Results showed that chain elongation of methyl (3) to n-butyl (6) causes a rise in the antioxidant activity. However, iso-propyl (7) and tert-butyl (9) were more active than the correspondent linear compounds, although sec-butyl (8) was less active among the chain ramified compounds. All the orsellinates were less active than lecanoric acid (1) and orsellinic acid (2). Orcinol (10) and resorcinol (11) were also determined for comparison with activities of orsellinates. Gallic acid (12) was used as control.
Synthesis and biological evaluation of cajanonic acid A derivatives as potential PPARγ antagonists
Guo, Bing,Hu, Chu-Jiao,Peng, Jin-Gang,Tang, Lei,Wang, Jian-Ta,Xia, Jing,Zhang, Ji-Quan,Zhu, Gao-Feng
supporting information, (2021/10/22)
Four series of cajanonic acid A (CAA) derivatives have been designed and synthesized. The newly prepared compounds have been screened for glucose consumption activity in HepG2 cell lines and PPARγ antagonistic activity in HEK293 cell lines. Compound 26g bearing a tetrahydroisoquinolinone scaffold showed the most potent PPARγ antagonistic and hypoglycemic activities. An oral glucose tolerance test (OGTT) was performed and the results further confirmed that 26g was a potent hypoglycemic agent. In addition, the possible binding modes for compound 26g in the PPARγ protein have been investigated in this study.
Stereoselective synthesis of resorcylic acid lactone Cochliomycin B
Nagalatha,Siva Ganesh,Venkat Narsaiah
, (2021/09/22)
The total synthesis of 14-membered resorcylic acid lactone, Cochliomycin B has prescribed, in a convergent manner, from readily available starting materials, D-galactose, L-aspartic acid and ethyl acetoacetate. The key reactions involved in the synthesis are Julia-Kocienski olefination, E-selective Horner-Wadsworth-Emmons olefination and intramolecular lactonization.
Secondary Metabolites of Onygenales Fungi Exemplified by Aioliomyces pyridodomos
Lin, Zhenjian,Kakule, Thomas B.,Reilly, Christopher A.,Beyhan, Sinem,Schmidt, Eric W.
, p. 1616 - 1626 (2019/06/17)
Fungi from the order Onygenales include human pathogens. Although secondary metabolites are critical for pathogenic interactions, relatively little is known about Onygenales compounds. Here, we use chemical and genetic methods on Aioliomyces pyridodomos, the first representative of a candidate new family within Onygenales. We isolated 14 new bioactive metabolites, nine of which are first disclosed here. Thirty-two specialized metabolite biosynthetic gene clusters (BGCs) were identified. BGCs were correlated to some of the new compounds by heterologous expression of biosynthetic genes. Some of the compounds were found after one year of fermentation. By comparing BGCs from A. pyridodomos with those from 68 previously sequenced Onygenales fungi, we delineate a large biosynthetic potential. Most of these biosynthetic pathways are specific to Onygenales fungi and have not been found elsewhere. Family level specificity and conservation of biosynthetic gene content are evident within Onygenales. Identification of these compounds may be important to understanding pathogenic interactions.
Inhibition of mushroom tyrosinase activity by orsellinates
Lopes, Thiago Inácio Barros,Coelho, Roberta Gomes,Honda, Neli Kika
, p. 61 - 64 (2018/01/05)
Several applications have been proposed for tyrosinase inhibitors in the pharmaceutical, food bioprocessing, and environmental industries. However, only a few compounds are known to serve as effective tyrosinase inhibitors. This study evaluated the tyrosinase-related activity of resorcinol (1), orcinol (2) lecanoric acid (3), and derivatives of this acid (4-15). Subjected to alcoholysis, lecanoric acid (3), a depside isolated from the lichen Parmotrema tinctorum, produces orsellinic acid (2,4-dihydroxy-6-methylbenzoic acid) (4) and orsellinates (2,4-dihydroxy-6-methyl benzoates) (5-15). At 0.50 mM, methyl (5), ethyl (6), n-propyl (7), tert-butyl (11), and n-cetyl orsellinates (15) acted as tyrosinase activators, whereas n-butyl (8), iso-propyl (9), sec-butyl (10), n-pentyl (12), n-hexyl (13), and n-octyl orsellinates (14) behaved as inhibitors. Tyrosinase inhibition rose with chain elongation-n-butyl (8) n-pentyl (12) n-hexyl (13) n-octyl orsellinates (14)-suggesting that the enzyme site can accept an eight-carbon alkyl chain. A kinetic study of n-octyl orsellinate (14) revealed uncompetitive inhibition of tyrosinase, with an inhibition constant of 0.99 mM.
First total synthesis of natural products cajanolactone A and cajanonic acid A
Chen, Wen-Zhang,Fan, Ling-Ling,Xiao, Hai-Tao,Zhou, Ying,Xiao, Wan,Wang, Jian-Ta,Tang, Lei
, p. 749 - 751 (2014/06/09)
First total synthesis of cajanolactone A and cajanonic acid A has been achieved through steps of anion-anion condensations, cyclization, Williams etherification, selective demethylation, 1,3-sigmatropic rearrangement and hydrolysis. This work provides an efficient method for future cajanonic acid A derivatives synthesis.
Zearalenone mimics: Synthesis of (E)-6-(1-Alkenyl)-substituted β-resorcylic acid esters
Mikula, Hannes,Hametner, Christian,Froehlich, Johannes
, p. 1939 - 1946 (2013/05/22)
Two versatile strategies for the synthesis of mimics of the Fusarium mycotoxin zearalenone (1) have been developed. Optimized preparation of (E)-6-(1-alkenyl) substituted β-resorcylic acid esters was realized via ortho-directed lithiation of variable substrates combined with allylation/isomerization or via formylation/Schlosser-Wittig olefination using different protective group patterns. Spontaneous decarboxylation of (E)-6-(1-alkenyl) substituted β-resorcylic acids indicated the influence of this substituent on the chemical behavior of these compounds. These mimics were already used for the development of optimized standard protocols for the synthesis of phase II metabolites of ZEN (glucosides, glucuronides), and further applications (i.e., sulfate conjugates) are still under investigation. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
Assembly of melleolide antibiotics involves a polyketide synthase with cross-coupling activity
Lackner, Gerald,Bohnert, Markus,Wick, Jonas,Hoffmeister, Dirk
, p. 1101 - 1106 (2013/10/01)
Summary Little is known about polyketide biosynthesis in mushrooms (basidiomycota). In this study, we investigated the iterative type I polyketide synthase (PKS) ArmB of the tree pathogen Armillaria mellea, a producer of cytotoxic melleolides (i.e., polyketides esterified with various sesquiterpene alcohols). Heterologously produced ArmB showed orsellinic acid (OA) synthase activity in vitro. Further, we demonstrate cross-coupling activity of ArmB, which forms OA esters with various alcohols. Using a tricyclic Armillaria sesquiterpene alcohol, we reconstituted the biosynthesis of melledonol. Intermolecular transesterification reactions may represent a general mechanism of fungal PKSs to create structural diversity of small molecules. Phylogenetic network construction of thioesterase domains of both basidiomycetes and ascomycetes suggests that the fungal nonreducing PKS family has likely evolved from an ancient OA synthase and has gained versatility by adopting Claisen-like cyclase or transferase activity.
Antimycobacterial activity of lichen substances
Honda,Pavan,Coelho,de Andrade Leite,Micheletti,Lopes,Misutsu,Beatriz,Brum,Leite
experimental part, p. 328 - 332 (2011/06/10)
We describe here the extraction and identification of several classes of phenolic compounds from the lichens Parmotrema dilatatum (Vain.) Hale, Parmotrema tinctorum (Nyl.) Hale, Pseudoparmelia sphaerospora (Nyl.) Hale and Usnea subcavata (Motyka) and determined their anti-tubercular activity. The depsides (atranorin, diffractaic and lecanoric acids), depsidones (protocetraric, salazinic, hypostictic and norstictic acids), xanthones (lichexanthone and secalonic acid), and usnic acid, as well seven orsellinic acid esters, five salazinic acid 8',9'-O-alkyl derivatives and four lichexanthone derivatives, were evaluated for their activity against Mycobacterium tuberculosis. Diffractaic acid was the most active compound (MIC value 15.6 μg/ml, 41.6 μM), followed by norstictic acid (MIC value 62.5 μg/ml, 168 μM) and usnic acid (MIC value 62.5 μg/ml, 182 μM). Hypostictic acid (MIC value 94.0 μg/ml, 251 μM) and protocetraric acid (MIC value 125 μg/ml, 334 μM) showed moderate inhibitory activity. The other compounds showed lower inhibitory activity on the growth of M. tuberculosis, varying from MIC values of 250 to 1370 μM.
