Redetermination and absolute configuration of 7α-hydroxyroyleanone

Abstract

The title compound [systematic name: 7α,12-dihy­droxy-8,12-abietadiene,11,14-dione or (4bS,8aS,10R)-3,10-dihy­droxy-2-isopropyl-4b,8,8-trimethyl-1,4,4b,5,6,7,8,8a,9,10-deca­hydro­phenanthrene-1,4-dione], C20H28O4, is an abietane diterpen­oid, which was isolated from the roots of Premna obtusifolia (Verbenaceae). Its crystal structure has been reported previously [Chen et al. (2000 ▶). Jiegou Huaxue, 19, 122–125], but the absolute configuration could not be determined using data collected with Mo radiation. This redetermination using Cu radiation shows the the absolute configurations of the stereogenic centres at positions 4b, 8a and 10 to be S, S and R, respectively. Two intra­molecular O—H⋯O hydrogen bonds [one generating an S(5) ring and one generating an S(6) ring] and a number of short C—H⋯O contacts occur. In the crystal, mol­ecules are linked into infinite chains propagating in [100] by O—H⋯O hydrogen bonds and weak C—H⋯O inter­actions.

11,12-Dihydroxy-10,6,8,11,13-icetexapentan-1-one

“…1) (Bernstein et al, 1995). The bond distances in (I) are within normal ranges (Allen et al, 1987) and comparable to the related structures (Asik et al, 2010;Razak et al, 2010).…”

“…For background to Verbenaceae plants and the bioactivity of icetexane, see: Bunluepuech & Tewtrakul (2009); Hymavathi et al (2009); Simmons & Sarpong (2009). For related structures, see: Asik et al (2010); Razak et al (2010). For the stability of the temperature controller used in the data collection, see Cosier & Glazer (1986).…”

“…Premna obtusifolia (Verbenaceae), a small tree found in the mangrove forests, is one of the Verbenaceae plants. As part of our research on bioactive compounds from medicinal plants, we previouly reported the crystal structures of diterpenoids from the roots of Premna obtusifolia (Verbenaceae) which was collected from Satun province in the southern of Thailand (Asik et al, 2010;Razak et al, 2010). The title icetexane diterpenoid (I), also named as Obtusin N, is a new compound which was isolated from the same plant.…”

In vitro cytotoxic activity of abietane diterpenes from Peltodon longipes as well as Salvia miltiorrhiza and Salvia sahendica

“…8,9,28 To compare the effect of ortho and para-quinone moieties on cytotoxicity we included six 20-nor-abietanes (13)(14)(15)(16)(17)(18) and one secoabietane diterpene (21) with an ortho-naphthoquinone structure, and two diterpenes lacking a quinone structure (19)(20). These compounds had been previously isolated from roots of Salvia miltiorrhiza 13 and S. sahendica (compounds 20 and 21).…”

“…Considering only the abietane diterpenes with an orthoquinone moiety our results confirm the recent SAR proposal of Wang et al9 who suggested an ortho-quinone moiety in ring C, an intact ring D, and a relatively planar structure as relevant structural features for cytotoxicity of these types of diterpenes. Chemical structures of the diterpenes isolated from Peltodon longipes (1-12), Salvia miltiorrhiza(13)(14)(15)(16)(17)(18)(19) and Salvia sahendica (20 and 21).…”