A diterpene from the marine brown alga Dictyota bartayresii

Diterpenes from the Marine Algae of the Genus Dictyota

“…Additionally, this compound also showed strong cytotoxicity against National Cancer Institute human small cell lung carcinoma (NCI-H187 cells) with an IC 50 value of 5.0 μg/mL, and potent anti-malarial activity with an IC 50 value of 3.22 μg/mL [ 32 ]. Another analog of pachydictyol A, 8 β -hydroxypachydictyol A ( 18 ), was reported from D. plectens [ 16 ], D. bartayresii [ 33 ] and D. dichotoma var. Implexa , collected from the Red Sea [ 15 ].…”

Hydroazulene Diterpenes from a Dictyota Brown Alga and Their Antioxidant and Neuroprotective Effects Against Cerebral Ischemia-Reperfusion Injury

“…The 1 H and 13 C NMR data revealed the presence of two acetoxy groups [δ H 2.04 (s), 1.98 (s); δ C 170.9 (C), 170.2 (C), 22.4 (CH 3 ), 21.3 (CH 3 )], three olefinic double bonds including one terminal [δ H 4.93 (br s, H-18a), 4.73 (br s, H-18b); δ C 148.9 (C, C-10), δ C 110.6 (CH 2 , C-18)] and two trisubstituted [δ H 5.35 (br s, H-3), 5.10 (t, J = 7.2 Hz, H-14); δ C 142.8 (C, C-4), 131.8 (C, C-15), δ C 125.3 (CH, C-14), 124.2 (CH, C-3)] ones, two oxygenated methines [δ H 5.39 (dd, J = 4.8, 1.2 Hz, H-8), 3.99 (ddd, J = 10.8, 7.2, 4.8 Hz, H-6); δ C 74.1 (CH, C-6), 72.3 (CH, C-8)], and an oxygenated nonprotonated carbon (δ C 88.2, C, C-11) (Tables and ). Detailed analysis of HMBC and COSY correlations suggested that 1 was a hydroazulene diterpene closely related to the co-occurring analogue 8β-hydroxypachydictyol A ( 7 ) . COSY correlations of H-6/6-OH (δ H 2.56, d, J = 10.8 Hz) and H-6/H-5 (δ H 2.62, t, J = 7.2 Hz) confirmed that C-6 (δ C 74.1, CH) was hydroxylated (Figure ).…”

“…(HMQC), heteronuclear multiple-bond correlation spectroscopy (HMBC), correlation spectroscopy (COSY), and nuclear Overhauser effect spectroscopy (NOESY)), high-resolution electrospray ionization mass spectrometry (HRESIMS), infrared (IR), and electronic circular dichroism (ECD) spectroscopic techniques. Five known compounds were identified as 8β,11-dihydroxypachydictyol A (6), 19 8β-hydroxypachydictyol A (7), 20 dictyol E (8), 21 dictyol C (9), 21 and acetyldictyol C (10) 22 by comparing their NMR (Tables S1 and S2) and MS spectroscopic data as well as specific rotations with those reported in the literature. Compound 1 has a molecular formula of C 24 H 36 O 5 as determined by HRESIMS data, which implied seven degrees of unsaturation.…”

“…Detailed analysis of HMBC and COSY correlations suggested that 1 was a hydroazulene diterpene closely related to the co-occurring analogue 8β-hydroxypachydictyol A (7). 20 COSY correlations of H-6/6-OH (δ H 2.56, d, J = 10.8 Hz) and H-6/H-5 (δ H 2.62, t, J = 7.2 Hz) confirmed that C-6 (δ C 74.1, CH) was hydroxylated (Figure 1). An acetoxy was attached to C-8 (δ C 72.3, CH) based on the HMBC correlation from H-8 (δ H 5.39, dd, J = 4.8, 1.2 Hz) to a carbonyl carbon (δ C 170.2, C) and COSY correlations between H-8 and H 2 -9 (δ H 2.87, dd, J = 14.4, 4.8 Hz; 2.17, dd, J = 14.4, 1.2 Hz).…”

Marine natural products

“…Dictyota bartayresii from Queensland yielded 8P-hydroxypachydictyol A (67). 75 In addition to the many diterpenes reported previo~sly,~~ an Indian Ocean specimen of D. divaricata contained divarinone (68), which possessed a new carbon D. fenestrata from South Australia contained (2S, 132)-2-acetoxyspata-13( 15),17-dien-10-01 ( 69) and (4R,9S, 132)-12-acetoxy-4-hydroxy-4,l O-secospata-2,13( 15), 17-trien-1 O-one (70), the structures of which were elucidated by chemical and spectroscopic methods. 78 Two dolastane diterpenes, (f)-(5S,12R, 14S)-dolasta-1(15),7,9trien-14-01 (71) from Dictyota spp."…”