Iridoids and Anthraquinones from the Malaysian Medicinal Plant, Saprosma scortechinii (Rubiaceae).

Abstract

Saprosma scortechinii BL. KING & GAMBLE, a rubiaceous plant endemic in the Malay Peninsula, 1) is also known as 'sekentut', a local name associated with the unpleasant and fetid odor emitted by the bruised plant tissues. In the traditional medicinal system of Malaysia, the roots are employed in decoctions to treat fever by the native communities, while the young leaves are also eaten as a vegetable.2) Our previous studies on the plant have resulted in the isolation of six sulfur-containing bis-iridoid glucosides (saprosmosides A-F) and 13 iridoid glucosides.3) On-going studies on the same plant materials have resulted in the isolation of two new bisiridoid glucosides, a new iridoid glucoside, and seven new anthraquinones, in addition to three known compounds. We wish to report herein the isolation and structural elucidation of these compounds. Results and DiscussionDried leaves and stems were separately extracted with methanol, and the resulting extracts were subjected to solvent-solvent partitioning. A combination of column chromatography followed by further purification led to the isolation of two new bis-iridoid glucosides (1 and 2) and a new iridoid glucoside (3) from the leaves, and seven new anthraquinones (4-10) from the stems, in addition to three known compounds identified as 6-O-acetylscandoside, The 1 H-and 13 C-NMR spectra ( ; 8-19-1 Nanakuma, Jyounanku, Fukuoka 814-0180, Japan. Received February 18, 2002; accepted May 8, 2002 A further investigation of the leaves and stems of Saprosma scortechinii afforded 13 compounds, of which 10 are new compounds. These were elucidated as the bis-iridoid glucosides, saprosmosides G (1) and H (2), the iridoid glucoside, 6-O-epi-acetylscandoside (3), and the anthraquinones, 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone (4), 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone 3-O-b b-primeveroside (5), 1,3-dihydroxy-2-carbomethoxy-9,10-anthraquinone 3-O-b b-primeveroside (6), 1,3,6-trihydroxy-2-methoxymethyl-9,10-anthraquinone (7), 1-methoxy-3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (8), 1,3,6-trihydroxy-2-hydroxymethyl-9,10-anthraquinone 3-O-b b-primeveroside (9), and 3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (10). Structure assignments for all compounds were established by means of mass and NMR spectroscopies, chemical methods, and comparison with published data. The new anthraquinones were derivatives of munjistin and lucidin.

Antiviral anthraquinones from the roots of Knoxia valerianoides

“…In addition to the three abovementioned new anthraquinones, nine known compounds were isolated from K. valerianoides. Through ESIMS analysis and comparisons with previously reported NMR data, their structures were confirmed as 1-methoxy-3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (4) (Ling et al, 2002), 3,6-dihydroxy-2-methoxymethyl-9,10-anthraquinone (5) (Chan et al, 2005), munjistin (6) (Itokawa et al, 1989), 1,2,3-trihydroxy-9,10-anthraquinone (7) (Dhananjeyan et al, 2005), arjunolic acid (8) (Shao et al, 1996), hyptatic acid A (9) (Yamagishi et al, 1988), hyptatic acid B (10) (Zhou et al, 1992), 2a,3b,24-trihydroxyurs-12-en-28-oic acid (11) (Li et al, 2014), and 2a,3b,23-trihydroxyurs-12-en-28-oic acid (12) (Adnyana et al, 2000). All of the isolates were evaluated their biological activities against Coxsackie virus B3 and influenza virus A/Hanfang/359/95.…”

“…for C 20 H 15 O 7 , 367.0823) and 13 C NMR data and indicated thirteen degrees of unsaturation. The IR spectrum displayed major absorption bands at 3406 cm À1 (hydroxy group), 1670 cm À1 (conjugated carbonyl), 1581 and 1462 cm À1 (aromatic ring was a tetra-substituted 9,10-anthraquinone derivative (ElGamal et al, 1995;Ling et al, 2002). Using the HSQC data, the remaining signals in the NMR spectrum of 1 were attributed to a methylene [d H 3.56 (2H, d, J = 8.6 Hz), d C 31.7, CH 2 -1 0 ], an oxymethine [d H 4.79 (1H, t, J = 8.6 Hz), d C 91.8, CH-2 0 ], an oxygenated quaternary carbon (d C 70.5, C-3 0 ) and two aliphatic methyl singlets [d H 1.18, 1.19 (each 3H, s), CH 3 -4 0 ,5 0 ], supporting the presence of a 2 0 ,3 0 -oxygen-bearing isopent-1 0 -yl moiety, which was confirmed by the HMBC correlations from H-1 0 to C-2 0 and C-3 0 , from H-2 0 to C-4 0 and C-5 0 , and from methyl protons to C-2 0 and C-3 0 .…”

Anthraquinones from the Roots of Knoxia valerianoides inhibit the formation of advanced glycation end products and rat lens aldose reductase in vitro

“…Seven anthraquinones (1-7) and one phenolic acid (8) were isolated from the EtOAc-and n-BuOHsoluble fractions of the roots of K. valerianoides, and were identified as lucidin (1) (Jegorov et al, 2005), lucidin-ω-methyl ether (2) (Chang and Lee, 1984), rubiadin (3) (Kawasaki et al, 1992;Likhitwitayawuid et al, 1999), damnacanthol (4) (Li et al, 2006;Lu et al, 1998), 1,3,6-trihydroxy-2-methoxymethylanthraquinone (5) (Ling et al, 2002), 3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (6) (Ling et al, 2002), 1,3,6-trihydroxy-2-hydroxymethyl-9,10-anthraquinone 3-O-β-primeveroside (7) (Ling et al, 2002), and vanillic acid (8) (Sakushima et al, 1995) by spectroscopic methods as well as by comparison of their data with literature values (Fig. 1).…”