New Thiophene and Flavonoid from Tagetes minuta Leaves Growing in Saudi Arabia

Abstract

Phytochemical investigation of the methanolic extract of Tagetes minuta L. (Asteraceae) leaves resulted in the isolation and identification of two new compounds: 5-methyl-2,2',5',2'',5'',2''',5''',2''''-quinquethiophene (1) and quercetagetin-6-O-(6-Ocaffeoyl-β-D-glucopyranoside) (9), in addition to seven known compounds: quercetin-3,6-dimethyl ether (2), quercetin-3-methyl ether (3), quercetin (4), axillarin-7-O-β-Dglucopyranoside (5), quercetagetin-3,7-dimethoxy-6-O-β-D-glucopyranoside (6), quercetagetin-7-methoxy-6-O-β-D-glucopyranoside (7), and quercetagetin-6-O-β-Dglucopyranoside (8). The compounds were identified by UV, IR, 1D, 2D NMR, and HRESIMS spectral data. They showed significant antioxidant activity, comparable with that of propyl gallate. Compounds 8 and 3 showed weak to moderate antileishmanial and antimalarial activities, with IC 50 values of 31.0 μg/mL and 4.37 μg/mL, respectively.

Blepharisides A and B, new flavonol glycosides from Blepharis ciliaris growing in Saudi Arabia

“…Thus, the aglycone part of 1 was assigned as quercetin and confirmed by the fragment ion peak at m/z 301 [M + H] + in the ESIMS spectrum (Mabry et al, 1970). Furthermore, two anomeric protons signals at d H 5.18 (d, J = 0.8 Hz, H-1 00 ) and 5.37 (d, J = 7.6 Hz, H-1 000 ), in addition a doublet methyl signal at d H 1.10 (d, J = 6.8 Hz, H-6 00 ), which correlated with the carbons at d C 99.9, 101.2, and 17.8, respectively, suggesting the presence of a-rhamnose and bglucose moieties in 1 (Al- Musayeib et al, 2014;Agrawal, 1992 ). This was confirmed by 13 C NMR signals at d C 124.9 (C-1 0000 ), 113.7 (C-2 0000 ), 145.8 (C-3 0000 ), 146.8 (C-4 0000 ), 115.9 (C-5 0000 ), 120.9 (C-6 0000 ), 145.0 (C-7 0000 ), 113.4 (C-8 0000 ), and 169.3 (C-9 0000 ) and further secured by the observed HMBC correlations (Fig.…”

Thiotagetin A, a new cytotoxic thiophene from Tagetes minuta

“…Its molecular formula was determined as C 27 H 24 O 2 S 5 based on the HRESIMS pseudo-molecular ion peaks at m/z 541.0459 [M + H] + and 542.0520 [M + 2H] + , requiring 16° of unsaturation. The UV spectrum displayed absorption bands at 335 and 389 nm characteristic for the quinquethiophene moiety (Bano et al 2002;Melucci et al 2004;Al-Musayeib et al 2014). The IR and 13 C NMR spectra indicated the presence of ester carbonyl at 1729 cm −1 and δ C 165.8 (C-21) (Silverstein & Webster 1998;Al-Musayeib et al 2013).…”

“…Moreover, it showed a wide range of biological properties, including α-amylase inhibitor, antimicrobial, anti-spasmodic, anti-parasitic, anti-septic, insecticidal, sedative, anti-inflammatory and acaricidal (Tereschuk et al 1997;Shahzadi et al 2010;Andreotti et al 2013;Ibrahim et al 2015). Previous chemical investigations of T. minuta growing in Saudi Arabia revealed the presence of thiophenes and flavonoids (Al-Musayeib et al 2014;Ibrahim et al 2015). In the present study, a new thiophene derivative: thiotagetin A (3), along with β-sitosterol (1) and stigmasterol (2) were isolated from the aerial parts of T. minuta ( Figure 1).…”

Prenylated flavonoids from the fruits of Sinopodophyllum emodi and their cytotoxic activities

“…2 Chinese medicinal herbs have become a promising source of potential new drugs. [9][10][11] In a further examination of the fruits of this plant, thirteen new prenylated avonoids, sino-avonoids C-O (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13), were obtained together with eleven known analogues (14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). Ying (Berberidaceae) called "Xiaoyelian" in Chinese, is a wellknown traditional Tibetan medicine for the treatment of amenorrhea, dead fetus, and placental retention.…”