Furoquinoline alkaloids are a group of alkaloids with simple structure. Distribution of this group of alkaloids is essentially limited to plant family Rutaceae. The simplest member of this group is dictamnine and most widespread member is skimmianine. [1]
A furoquinoline alkaloid, dictamnine, is very common within the family Rutaceae. It is the main alkaloid in the roots of Dictamnus albus and responsible for the mutagenicity of the drug derived from crude extracts. [2] Dictamnine was also reported to be a phototoxic and photomutagenic compound. [3] It participates in the severe skin phototoxicity of the plant. [4] Another furoquinoline alkaloid, skimmianine, has strong antiacetylcholinesterase activity. [5]
Thomas first isolated dictamnine from Rutaceae in 1923. It is very weak base, shows similar reaction with methyl iodide and dimethyl sulfate or diazomethane, does not form a derivative but go through isomerization to isodictamnine. Dictamine have linear structure which is confirmed as it forms dictamnic acid by oxidative degradation with potassium permanganate. Dieckmann cyclization followed by methylation and hydrolysis confirmed the structure of the acid. Skimmianine, another common furoquinoline alkaloid also shows a very similar type of chemistry to dictamine. Skimmianine also has a linear structure as it gave 3-ethyl-4,7,8-trimethoxy-2-quinolone from hydrolysis. [1]
Some furoquinoline alkaloids have been found to have in vitro pharmacological properties such as antimicrobial, antiviral, mutagenic and cytotoxic activities. They also show antiplatelet aggregation, inhibition of various enzymes, antibacterial, and antifungal activity. [6] Dictamnine has the property of causing smooth muscle contraction. [1] Skimmianine, [1] extracted from Esenbeckia leiocarpa Engl. (Rutaceae), a native tree from Brazil popularly known as guarantã, show acetylcholinesterase inhibition. [7] Furoquinoline alkaloids extracted from Teclea afzelii (Rutaceae) plants, collected at Elounden, centre province of Cameroon, have antiplasmodial activities. [8] Another study shows that some furoquinoline alkaloids have in vitro activity against Plasmodium falciparum , one of the species of Plasmodium that causes malaria in humans. [9] One furoquinoline alkaloid, 5-(1,1-dimethylallyl)-8-hydroxy-furo[2-3-b]quinolone, shows antifungal properties against Rhizoctonia solani , Sclerotium rolfsi , and Fusarium solani . These fungi cause root-rot and wilt diseases in potato, sugar beet and tomato. [6]
For UV spectra an intense band is observed at 235 nm and very broad band in region 290-335 nm. Compared to UV, IR spectra shows less characteristics: 1090–1110 cm−1 region shows a band but don't indicate a particular vibration. NMR spectroscopy is the best way to observe the structure of furoquinoline alkaloids. C-2 proton gives response in 7.50-7.60 ppm region and C-3 proton gives response in 6.90-7.10 ppm region. Aromatic methoxy group give responses in 4.0-4.2 ppm region but 4-methoxy group give responses in ~4.40 ppm region. [1]
Antimalarial medications or simply antimalarials are a type of antiparasitic chemical agent, often naturally derived, that can be used to treat or to prevent malaria, in the latter case, most often aiming at two susceptible target groups, young children and pregnant women. As of 2018, modern treatments, including for severe malaria, continued to depend on therapies deriving historically from quinine and artesunate, both parenteral (injectable) drugs, expanding from there into the many classes of available modern drugs. Incidence and distribution of the disease is expected to remain high, globally, for many years to come; moreover, known antimalarial drugs have repeatedly been observed to elicit resistance in the malaria parasite—including for combination therapies featuring artemisinin, a drug of last resort, where resistance has now been observed in Southeast Asia. As such, the needs for new antimalarial agents and new strategies of treatment remain important priorities in tropical medicine. As well, despite very positive outcomes from many modern treatments, serious side effects can impact some individuals taking standard doses.
Harmaline is a fluorescent indole alkaloid from the group of harmala alkaloids and beta-carbolines. It is the partly hydrogenated form of harmine.
Carvacrol, or cymophenol, C6H3(CH3)(OH)C3H7, is a monoterpenoid phenol. It has a characteristic pungent, warm odor of oregano.
Cycloguanil is a dihydrofolate reductase inhibitor, and is a metabolite of the antimalarial drug proguanil; its formation in vivo has been thought to be primarily responsible for the antimalarial activity of proguanil. However, more recent work has indicated that, while proguanil is synergistic with the drug atovaquone, cycloguanil is in fact antagonistic to the effects of atovaquone, suggesting that, unlike cycloguanil, proguanil may have an alternative mechanism of antimalarial action besides dihydrofolate reductase inhibition.
Alternariol is a toxic metabolite of Alternaria fungi. It is an important contaminant in cereals and fruits. Alternariol exhibits antifungal and phytotoxic activity. It is reported to inhibit cholinesterase enzymes. It is also a mycoestrogen.
Fleroxacin is a quinolone antibiotic. It is sold under the brand names Quinodis and Megalocin.
Clinafloxacin is an investigational fluoroquinolone antibiotic. Despite its promising antibiotic activity, the clinical development of clinafloxacin has been hampered by its risk for inducing serious side effects.
Evoxine (haploperine) is a furoquinoline alkaloid with hypnotic and sedative effects. It is found naturally in a variety of Australian and African plants including Evodia xanthoxyloides and Teclea gerrardii.
Warburgia ugandensis, also known as Ugandan greenheart or simply greenheart tree, is a species of evergreen tree native to East Africa. Countries in which the plant species is found include Kenya, Tanzania and Uganda. The wood is resistant to insect attack and very strong. It was commonly used for the yoke pole of ox-wagons, the Disselboom. Early Indian immigrants to Kenya, working on the construction of the railway, used the leaves to flavor their curries before the chilli plant was commonly introduced. The flavor is hot and subtly different from chillies.
Ziziphus oenopolia, commonly known as the jackal jujube, small-fruited jujube or wild jujube, is a flowering plant with a broad distribution through tropical and subtropical Asia and Australasia. In India, it is mostly found in the deciduous forests of the southern part of the country.
Panicudine (6-hydroxy-11-deoxy-13-dehydrohetisane) is a C20-diterpene alkaloid of the hetisine type, first isolated from Aconitum paniculatum. It has empirical formula C20H25NO3 and a melting point of 249–250 °C. The structure was determined to be a hetisine type diterpene by noting infrared spectrum absorption bands of 3405 cm−1 (OH), 1718 (C=O), and 1650 (C=C), a proton magnetic resonance spectrum with "secondary hydroxy (4.02 ppm, m, 1H, W1/2 = 10 Hz), exomethylene (4.87 and 4.76 ppm, br.s, 1H each), and tertiary methyl (1.29 ppm, s, 3H) groups and the absence of N-methyl, N-ethyl, and methoxy groups." Additional ultraviolet spectrum and carbon-13 NMR data, confirmed by high resolution mass spectrometry, completed the determination of the structure.
Villalstonine is a bisindole alkaloid isolated from Alstonia with in vitro antiplasmodial activity.
Corydaline is an acetylcholinesterase inhibitor isolated from Corydalis yanhusuo.
Geissolosimine is an antiplasmodial indole alkaloid isolated from the bark of Geissospermum vellosii.
Clausena anisata (Willd.) Hook.f. ex Benth. is a deciduous shrub or small tree, belonging to the Rutaceae or Citrus family, and widespread in the Afrotropical realm or Sub-Saharan Africa, but absent from the drier regions. It is also found in tropical and South-East Asia, growing in India and Sri Lanka and extending as far as Queensland in north-eastern Australia and some Pacific islands. It is cultivated in Malaysia and Indonesia. As with other plants useful to mankind its large range of medicinal properties has led to a global distribution and its growth wherever the climate is suitable. It grows in higher-rainfall regions in savanna, thickets, riverine forest, disturbed areas and secondary forest, up to an altitude of 3000 m. The leaves, which are foetid when bruised, give rise to the common name 'Horsewood' or the more descriptive Afrikaans common name 'Perdepis', meaning 'horse urine'.
Sarcococca saligna, the sweet box or Christmas box, is a species of flowering plant in the family Buxaceae. This shrub is native to northern Pakistan. Its common name in Pakistan is sheha.
Skimmianine is a furoquinoline alkaloid found in Skimmia japonica, a flowering plant in family Rutaceae that is native to Japan and China. It is also a strong acetylcholinesterase (AChE) inhibitor.
Lichexanthone is an organic compound in the structural class of chemicals known as xanthones. Lichexanthone was first isolated and identified by Japanese chemists from a species of leafy lichen in the 1940s. The compound is known to occur in many lichens, and it is important in the taxonomy of species in several genera, such as Pertusaria and Pyxine. More than a dozen lichen species have a variation of the word lichexanthone incorporated as part of their binomial name. The presence of lichexanthone in lichens causes them to fluoresce a greenish-yellow colour under long-wavelength UV light; this feature is used to help identify some species. Lichexanthone is also found in several plants, and some species of fungi that do not form lichens.
David A. Fidock, is the CS Hamish Young Professor of Microbiology and Immunology and Professor of Medical Sciences at Columbia University Irving Medical Center in Manhattan.
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