Comparative Hypotensive Effects of Compounds Extracted fromLippia multifloraLeaves

Abstract

The marked hypotensitive effects of the methanolic extract evidenced in Lippia multiflora leaves prompted us to search for the active principle responsible for such an activity in anaesthetized rats. The methanolic extract was then fractionated according to a scheme of processes and by means of various solvents. Data obtained under the experimental conditions adopted, showed that the hypotensive principle of Lippia multiflora leaves are not flavonic: they are rather phenolic. From the phenolic fraction, two pure products were isolated: inactive verbascoside and Li 1, a cafeic acid ester, linked to 3,4-dihydroxyphenylethanol, the chemical structure of which has not been elucidated yet. Lii exhibited a marked and long-lasting hypotensive effect. The study of dose-response curves of the phenolic fraction and Li 1 showed that Li 1 could be one of the major -ifnot the only oneactive principles responsible for the hypotensive action of Lippia multi!bra leaves.

Chemical Constituents from Lippia sidoides and Cytotoxic Activity

“…The genus Lippia (Verbenaceae) comprises a great number of medicinal and economically important species, including several that are used in traditional Brazilian medicine. , Lippia sidoides Cham., popularly known as “alecrim pimenta”, is an odoriferous plant that grows wild in the northeastern region of Brazil. In the traditional medicine the aerial parts of this species are used as an anti-infective agent, particularly as an antiseptic.…”

“…The cytotoxic effects of some of the compounds against three cancer cell lines (HL60, SW1573, and CEM) were evaluated. The nomenclature and numbering of the new natural product 13 follow the two prenylated naphthoquinone moieties as biogenetic precursors.The known compounds (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) were identified on the basis of spectral analysis involving comparison with literature data. In a previous paper we reported the results of extensive application of 1D and 2D NMR techniques to establish the complete 1 H and 13 C resonance assignments of tecomaquinone (4), tectol (6), and the acetyl derivative of tectol (7).…”

“…The 13 The NOESY spectrum of 13 furnished information about spatial proximity (dipolar coupling) between hydrogen atoms (Table 1), which allowed the relative configuration to be established as shown in Figure 1. 1 J HH values and the cross-peaks observed in the 1 H-1 H NOESY spectrum of 13 (Table 1 and Figure 1) were used to assign the hydrogens H-14′R and H-14′β (δ H 2.17, dd, J ) 20.0 and 8.2 Hz), since only the later revealed NOE with H-6β (δ H 2.92, dd, J ) 1.7 and 8.2 Hz). Thus, the structure of the new dimer 13 containing two prenylated naphthoquinoid moieties (1 to 15 and 1′ to 15′), named lippisidoquinone, has been characterized.…”

A Novel Method for the Synthesis of Substituted Benzochromenes by Ethylenediamine Diacetate‐Catalyzed Cyclizations of Naphthalenols to α,β‐Unsaturated Aldehydes. Concise Synthesis of the Natural Products Lapachenole, Dihydrolapachenole, and Mollugin

“…As an application of this methodology, a concise synthesis of the natural products lapachenole (1), dihydrolapachenole (2), and mollugin (3) was attempted. Although several approaches for the synthesis of lapachenole (1) have been reported [26], there are no simple and efficient synthetic approaches.…”

“…Therefore, the OH group at C(4) of compound 31 was protected with chloromethyl methyl ether (MOMCl) in an attempt to increase the yield. First, a treatment of compound 31 with (t-Bu)Me 2 SiCl (TBSCl) at room temperature for 10 h in DMF in the presence of Et 3 N gave compound 32 in 85% yield, which was reacted directly with MOMCl at room temperature for 12 h in CH 2 Cl 2 in the presence of EtN (i-Pr) 2 Conclusions. -A new synthetic route for biologically interesting benzochromenes (¼ naphthopyrans) starting from naphthalenols was further developed.…”