Two new phenylpropanoids and a new dihydrostilbenoid from the flower buds of Magnolia biondii pamp and their acetylcholinesterase inhibitory activities

Abstract

Two new phenylpropanoids, named (2'R*,3'R*)-2',3'-dihydroxy-4'-methoxy-caffeoyl butyrate (1), 9-acetoxy syringin (2), and a new dihydrostilbene, named (8'R)-4',5-dihydroxy-4,8'-dimethoxy-2-hydroxyethyl diphenylethane (3), together with five analogues (4-8), were isolated from the flower buds of Magnolia biondii Pamp. Their structures were elucidated by extensive spectroscopic analyses and comparison with literature data. The absolute configurations were deduced by comparison of experimental and calculated gauge-independent atomic orbital (GIAO) 1D NMR data. Moreover, the isolated compounds (1-8) were evaluated in vitro for their acetylcholinesterase (AChE) inhibitory activities.

Natural Products from Leaves of the Ancient Iranian Medicinal Plant Echium amoenum Fisch. & C. A. Mey.

“…The coupling constant observed between H7 and H8 (12.9 Hz) confirmed the identity of compound 3 to be 4-Oxy-(Z)-Caffeoyl-2,3-dihydroxybutanoic acid methyl ester (Figure 2). Very recently, Cao et al identified 4-Oxy-(E)-Caffeoyl-2 R,3 R-2,3-dihydroxybutanoic acid methyl ester as a novel natural product from the flower buds of Magnolia biondii pamp [16]. The UV and the 1 H and 13 C NMR data of compound 2 are in good agreement with the NMR data reported for the similar compound by Cao et al ( 2021), with only relatively minor differences of chemical shift values due to solvent differences because the NMR data of Cao et al were recorded in a different solvent (CD 3 OD) [16].…”

“…For the first time, polyphenolic compounds of leaves of E. amoenum have been isolated and identified. The fact that compound 1 belongs to a rare group of natural products which have previously been patented for their significant anti-inflammatory activity by Matano et al (1993) [16] may rationalize the traditional treatment of inflammations with E. amoenum.…”

Three New 2,2′‐Difurylketone Derivatives and Two New Chromones from the Rehmanniae Radix Praeparata

“…The acid hydrolysis method was the same as the reported literature [19] . Thus, the sugar was determined to be D‐galactose by comparison to that of standard substance [t R : (i) 17.0 min].…”

Chemical composition, antioxidant activity and cytotoxicity of flower extracts from Magnolia grandiflora L. found in southeast Mexico

“…In Mexican traditional medicine it has been used as treatment against epilepsy, spams, inflammatory and infertility diseases (Dominguez-Yescas and Vázquez-García, 2019). DOI: 10.18633/biotecnia.v25i1.1680 6 Rivas-Garcia et al: Biotecnia / XXV (1): 5-13 (2023) Many reports state that different plant structures of M. grandiflora contain active compounds such as sesquiterpenoides (Hong et al, 2007), coumarins (Hussein and El-Anssary, 2019), phenylpropanoids (Cao et al, 2021), lignans (Schühly et al, 2009), glycosides (Wang et al, 2019), alkaloids (Cho et al, 2022), among others (Lim, 2014). These compounds have demonstrated biological activities such as antitumor (Chilampalli et al, 2011), antimicrobial (Chang et al, 1998, anti-inflammatory (Kim and Cho, 2008), anti-tyrosinase (Huang et al, 2012), anti-allergic (Niitsuma et al, 2001), cardioprotective (Ho and Hong, 2012) and antiviral (Lan et al, 2012) activities.…”