Ginkgo biloba L., also popularly known as living fossil, possesses a variety of biological and pharmacological activities. The leaf extract of G. biloba L. (EGb 761) has been used for years to treat age-related memory-deficit problems, including Alzheimer's and dementia. Experimental and clinical studies have revealed its beneficial effects on a wide range of pathological conditions including hepatoprotective, photoprotective effects, DNA repair mechanism, antioxidant and anti-inflammatory activities. Recent studies have also suggested that leaf extract of G. biloba L. may exert beneficial effects on cancer. This review focuses on recent scientific evidence of the reported medicinal effects of G. biloba L.
Treatment of acetylenic or olefinic carbonates and esters with a
low-valent titanium reagent diisopropoxy(η2-propene)titanium (1), readily
generated by the reaction of Ti(O-i-Pr)4 or
ClTi(O-i-Pr)3 with 2i-PrMgX,
in an intramolecular nucleophilic acyl substitution (INAS) reaction to
afford organotitanium compounds having a
carbonyl functional group, in good to excellent yields. Thus, the
treatment of alkyl alkynyl carbonates 2 or
alkenyl carbonates 4 with 1 gave organotitanium
compounds having a lactone and/or ester group. Similarly,
alkynoates 10 or alkynyl esters 14 of carboxylic
acids reacted with 1 to give organotitanium compounds having
cyclic or acyclic ketone group, respectively. Thus, the reaction
provides, after hydrolysis, five- or six-membered
α-alkylidene lactones and/or α,β-unsaturated esters from
2, γ-butyrolactone derivatives from 4, five- or
α-alkylidene cyclic ketones from 10, and acyclic
α,β-unsaturated ketones 15 from 14. In
all cases, the yields are
excellent and the generation of the organotitanium compounds was
confirmed by deuterolysis. The organotitaniums
6 and 11c reacted smoothly with iodine to afford
2-(iodomethyl)-4-butanolide (9) and
α-[iodo(trimethylsilyl)methylidene]cyclopentanone, respectively. The organotitanium
compounds obtained here also reacted with aldehydes
to give the corresponding adducts, thus opening up a new access to
substituted α,β-butenolides from 2, to
γ-butyrolactones from 4, and to the corresponding
tetrasubstituted furan from 10 and
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The sharp spurt in positive cases of novel coronavirus-19 (SARS-CoV-2) worldwide has created a big threat to human. In view to expedite new drug leads for COVID-19, Main Proteases (M pro) of novel Coronavirus (SARS-CoV-2) has emerged as a crucial target for this virus. Nitric oxide (NO) inhibits the replication cycle of SARS-CoV. Inhalation of nitric oxide is used in the treatment of severe acute respiratory syndrome. Herein, we evaluated the phenyl furoxan, a well-known exogenous NO donor to identify the possible potent inhibitors through in silico studies such as molecular docking as per target analysis for candidates bound to substrate binding pocket of SARS-COV-2 M pro. Molecular dynamics (MD) simulations of most stable docked complexes (M pro-22 and M pro-26) helped to confirm the notable conformational stability of these docked complexes under dynamic state. Furthermore, Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) calculations revealed energetic contributions of key residues of M pro in binding with potent furoxan derivatives 22, 26. In the present study to validate the molecular docking, MD simulation and MM-PBSA results, crystal structure of M pro bound to experimentally known inhibitor X77 was used as control and the obtained results are presented herein. We envisaged that spiro-isoquinolino-piperidine-furoxan moieties can be used as effective ligand for SARS-CoV-2 M pro inhibition due to the presence of key isoquinolino-piperidine skeleton with additional NO effect.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.