Читать книгу Secondary Metabolites of Medicinal Plants - Bharat Singh - Страница 27

Ageratum conyzoides L. (Fam. – Asteraceae) is an annual, branched, height up to 1 m with hairy ovate leaves; is used as purgative, febrifuge, and to treat ulcers as well as cleaning and healing of wounds (Kerharo and Adam 1974), skin and mental problems, headaches and dyspnea (Durodola 1977). It is used as anti-asthmatic, antispasmodic, and hemostatic agent (Kokwaro 1976). The aerial parts are used to treat uterine troubles as well as pneumonia by rubbing on the chest of patients (Katsuri et al. 1973; Abbiw 1990), and leprosy in India (Katsuri et al. 1973). The A. conyzoides showed anti-inflammatory, analgesic, antidiarrheal, insecticidal, antitumor (Sharma and Sharma 1995; Moreira et al. 2007; Adebayo et al. 2010a; Acheampong et al. 2015), antioxidant, gastroprotective, and cytotoxic effects (Galati et al. 2001; Shirwaikar et al. 2003; Preeti et al. 2009; Adebayo et al. 2010b).

The hexane extract of A. conyzoides showed the presence of 5,6,7,8,3,4,5-heptamethoxyflavone; 5,6,7,8,3-pentamethoxy-4,5-methylenedioxyflavone and coumarin; 5,6,7,8,3-pentamethoxy-4,5-ethylenedioxyflavone; 5,6,7,8,3,4,5-heptamethoxyflavone, ageratochromene and 7-methoxy-2,2-dimethylchromene (Aalbersberg and Singh 1991; Moreira et al. 2007), methoxyflavones, 5,6,8,3′,4′,5′-hexamethoxyflavone and 8-hydroxy-5,6,7,3′,4′,5′-hexamethoxyflavone (González et al. 1991a; Dũng et al. 1989), 5,6,7,3′,4′,5′-hexamethoxyflavone, 5,6,7,8,3′,4′-hexamethoxyflavone, 5,6,7,8,3′,4′,5′-heptamethoxyflavone, 5,6,7,3′, 4′-pentamethoxyflavone, 5,6,7,3′-tetramethoxy-4′,5′-methylenedioxyflavone (Acheampong et al. 2017), ageratochromene, β-caryophyllene, demethoxyageratochromene (Sundufu and Shoushan 2004), (2S)-7,3′,4′-trimethoxyflavanone, (2S)-7-methoxy-3′,4′-methylenedioxyflavone, 5,6,7,8,5′-pentamethoxy-3′,4′-methylenedioxyflavone, 5,2′-dihydroxy-7-methoxyflavone, 2′-O-β-D-glucopyranoside and kaempferol-3-O-α-L-rhamnopyranoside (Munikishore et al. 2013), and 5,6,7,3′,4′,5-hexamethoxyflavone (Horie et al. 1993).

The essential amino acids like α-pinene, β-pinene, β-myrcene, 1,8-cineole, linalool, borneol, 4-terpineol, α-terpineol, bornyl acetate, α-cubebene, α-longipine, eugenol, copaene, β-cubebene, methyleugenol, (Z)-caryophyllene, β-caryophyllene, α-bergamotene, α-caryophyllene, (E)-β-farnesene, precocene I, germacrene D, viridiflorene, γ-cadinene, β-sesquiphellandrene, dihydroactinidiolide, cis-nerolidol, spathulenol, caryophyllene oxide, humulene oxide II, precocene II, β-bisabolol (Liu and Liu 2014), sabinene, eugenol and methyleugenol, caryophyllene epoxide, β-sesquiphellandrene, δ-cadinene, τ-cadinene, ageratochromene, 6-methoxyquinoline 1-oxide, β-caryophyllene oxide, and β-sinensal were identified from A. conyzoides (Ekundayo et al. 1988; Rana and Blazquez 2003; Wandji et al. 1996; Pham et al. 1976; Quij ano et al. 1982; Sharma et al. 1980).

Other chromene compounds such as encecalin, 6-vinyl-7-methoxy-2,2-dimethylchromene, dihydroencecalin, dihydrodemethoxyencecalin, demethoxyencecalin, demethylencecalin and 2-(1′-oxo-2′-methylpropyl)-2-methyl-6,7-dimethoxychromene, 2,2-dimethylchromene-7-O-β-glucopyranoside, 6-acetyl-2,2′-dimethyl-3,4-dihydrochromene, 6-(1-methoxy ethyl)-7-methoxy-2,2-dimethylchromene, 6-(1-hydroxy ethyl)-7-methoxy-2,2-dimethylchromene, 6-(1-ethoxyethyl)-7-methoxy-2,2-dimethylchromene, 6-angeloyloxy-7-methoxy-2,2-dimethylchromene, encecanescin, 2-(2′-methylethyl)-5,6-dimethoxybenzofuran, 14-hydroxy-2Hβ, 3-dihydroeuparine, 6,7,6′,7′-tetramethoxy-2,2,2′,2′-tetramethyl-3′(4′)-dehydro-3′-4S-bichromene, 3-(2′-methyl propyl)-methyl-6,8-dimethoxychrom-4-one and 2-(2′-methylprop-2′-enyl)-2-methyl-6,7-dimethoxychroman-4-one (Pari et al. 1998; Ahmed et al. 1999; González et al. 1991a; Desai et al. 1973; Srivastava et al. 1985; Katsuri et al. 1973), 5,6,7,8,3′,4′,5′-heptamethoxyflavone (Adesogan and Okunade 1979), 6-(1′-hydroxyethyl)-2,2-dimethylchromene, conyzorigun, and 7-hydroxyl-2,2-dimethylchromene were reported from hexane extract of aerial parts of A. conyzoides (Vyas and Mulchandani 1984; Kasali et al. 2002).

Several polyoxygenated flavones such as ageconyflavones A, B, and C, linderoflavone B, eupalestin, nobiletin, 5′-methoxynobiletin, 5,6,7,5′-tetramethoxy-3′,4′-methylenedioxyflavone, sinensetin, 5,6,7,3′,4′,5′-hexamethoxyflavone, 5,6,7,8,3′-pentamethoxy-4′-hydroxyflavone and 5,6,7,8,3′,5′-hexamethoxy-4′-hydroxyflavone (Vyas and Mulchandani 1986), O-methyl apigenin, and scutellarein tetramethyl ether (Phat and Ngoan 2016); other related compounds obtained from the oil include encecalin, 6-vinyl-7-methoxy-2,2-dimethylchromene, dihydroencecalin, dihydrodemethoxyencecalin, demethoxyencecalin, demethylencecalin (Ekundayo et al. 1988), and 2,2-dimethylchromene-7-O-β-glucopyranoside and 2-(1′-oxo-2′-methylpropyl)-2-methyl-6,7-dimethoxychromene (Pari et al. 1998; Ekundayo et al. 1988); and polyhydroxyflavones such as scutellarein-5,6,7,4′-tetrahydroxyflavone, quercetin, quercetin-3-rhamnopyranoside, kaempferol, kaempferol-3-rhamnopyranoside and kaempferol 3,7-diglucopyranoside (Palanniappan et al. 1983; Singh et al. 2013), 2,2-dimethylchromene-7-O-β-glucopyranoside (Ahmed et al. 1999), 6-(1-methoxyethyl)-7-methoxy-2,2-dimethylchromene, 6-(1-hydroxyethyl)-7-methoxy-2,2-dimethylchromene, 6-(1-ethoxyethyl)-7-methoxy-2,2-dimethylchromene, 6-angeloyloxy-7-methoxy-2,2-dimethylchromene, and an inseparable mixture of encecanescins have been isolated from A. conyzoides (González et al. 1991b).

Benzofuran derivatives such as 2-(2′-methylethyl)-5,6-dimethoxybenzofuran and 14-hydroxy-2Hβ,3-dihydroeuparine (Ahmed et al. 1999) as well as chromone derivatives, 3-(2′-methylpropyl)-2-methyl-6,8-dimethoxychrom-4-one and 2-(2′-methylprop-2′-enyl)-2-methyl-6,7-dimethoxychroman-4-one, have also been identified from this plant species (Pari et al. 1998). Besides benzofuran derivatives, the triterpenes such as friedelin, β-sitosterol, stigmasterol, brassicasterol, dihydrobrassicasterol, spinasterol, dihydrospinasterol, lycopsamine, echinatine, (+)-sesamin, aurantiamide acetate, fumaric acid, caffeic acid, phytol and hydrocarbons, (nC₂₇–H₅₆ to nC₃₂–H₆₆) have also been isolated from A. conyzoides (Wiedenfeld and Roder 1991; Riaz et al. 1991).

Ageratum conyzoides is very rich in polyoxygenated flavonoids (González et al. 1991b; Vyas and Mulchandani 1986; González et al. 1984; Quijano 1980a,b; Adesogan and Okunade 1978, 1979; Horie et al. 1993), 3′,4′,5′-oxygenated flavones, 5′-methoxynobiletin, linderoflavone B, 5,6,7,3′,4′,5′-hexamethoxyflavone, 5,6,8,3′,4′,5′-hexamethoxyflavone, eupalestin (González et al. 1991a; Vyas and Mulchandani 1986), scutellarein-5,6,7,4′-tetrahydroxyflavone, quercetin, quercetin-3-rhamnopyranoside, kaempferol, kaempferol-3-rhamnopyranoside, and kaempferol 3,7-diglucopyranoside (Gill et al. 1978; Nair et al. 1977; Yadara and Kumar 1999). The coumarins such as ageratochromene, β-caryophyllene, caffeic acid, caryophyllene epoxide, echinatine, eugenol, fumaric acid, kaempferol-3,7-diglucopyranoside, precocene I, precocene II α-pinene, β-pinene, δ-cadinene, 2-(1′-oxo-2′-methylpropyl)-2-methyl-6,7-dimethoxy-chromene, 2-(2′-methylprop-2′-enyl)-2-methyl-6,7-dimethoxychroman-19-one, -(2′-methylpropyl)-2-methyl-6,8-dimethoxychrom-19-one,2-(2′-methylethyl)-5,6-dimethoxybenzofuran, 5,7,2′,19′-tetrahydroxy-6,3′-di-(3,3-dimethylallyl)-isoflavone, 5-O-α-l-rhamnopyrosyl-(1→19)-α-l-rhamnopyranoside, methyl-6,7-dimethoxy chromene have been reported from A. conyzoides (Singh et al. 2013; Kupriyanova 1997; Adebayo et al. 2010a,b), encecalol and demethoxyencecalol (González et al. 1991b), sesamin (Moazzami et al. 2007), linderoflavone B (Saxena and Shrivastava 1994), 3′-hydroxy-5,6,7,8,4′,5′-hexamethoxyflavone (Herz and Kulanthaivel 1982), 5′-methoxynobiletin (Le-Van and Van Cuong Pham 1979; Herz et al. 1980), and 2-hydroxycinnamic and 2-hydroxydihydrocinnamic acids have been reported from A. conyzoides (Gerothanassis et al. 1998). The lycopsamine, lycopsamine N-oxide, dihydrolycopsamine, dihydrolycopsamine N-oxide, acetyllycopsamine, and acetyllycopsamine N-oxide were isolated from A. conyzoides (Okunade 2002; Bosi et al. 2013).