New Natural Diterpene-Type Abietane from Tetradenia riparia Essential Oil with Cytotoxic and Antioxidant Activities

Abstract

Tetradenia riparia (Hochstetter) Codd belongs to the Lamiaceae family and it was introduced in Brazil as an exotic ornamental plant. A previous study showed its antimicrobial, acaricidal and analgesic activities. Two compounds were isolated from essential oil of T. riparia leaves and identified as 9β,13β-epoxy-7-abietene (1), a new one, OPEN ACCESSMolecules 2014, 19 515 and 6,7-dehydroroyleanone (2), already reported for another plant. The structure of these compounds was determined by spectroscopic analysis and by comparison with literature data. The cytotoxic activities of the essential oil and compounds 1 and 2 were determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, and by tumor cells MDA-MB-435 (human breast carcinoma), HCT-8 (human colon), SF-295 (human nervous system) and HL-60 (human promyelocytic leukemia). The essential oil and compound 1 showed high cytotoxic potential of the cell lines SF-295 (78.06% and 94.80%, respectively), HCT-8 (85.00% and 86.54%, respectively) and MDA-MB-435 (59.48% and 45.43%, respectively). Compound 2 had no cytotoxic activity. The antioxidant activity was determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), β-carotene-linoleic acid system and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The inhibitory concentration (IC 50 in µg mL −1 ) for essential oil and compound 2 was, respectively 15.63 and 0.01 for DPPH; 130.1 and 109.6 for β-carotenelinoleic acid and 1524 and 1024 for ABTS. Compound 1 had no antioxidant activity. By fractioning the oil, it was possible to identify two unpublished compounds: 1 with high cytotoxic potential and 2 with high antioxidant potential.

Cytotoxicity screening of essential oils in cancer cell lines

“…13-Epimanoyl oxide (7.2%) was the only diterpene identified in TR-EO. The oxygenated diterpenes calyculone, 14-hydroxy-9-epi-caryophyllene, cis-muurolol-5-en-4-ol, which were identified as major constituents in the essential oil of other T. riparia specimens (Fernandez et al, 2014;Gazim et al, 2010Gazim et al, , 2014 were not detected in TR-EO. TE-OE exerted the most pronounced antiproliferative effect against the tumor cell lines.…”

“…Despite the reports on the biological activities of these essential oils, data on their cytotoxicity are still scarce in the literature (Fabio et al, 2007;Gazim et al, 2014;Villarini et al, 2014).…”

“…Its oil presents a complex mixture of monoterpenes, sesquiterpenes and diterpenes. The oxygenated diterpenes calyculone, 9␤,13␤-epoxy-7-abietene and 6,7-dehydroroyleanone; the oxygenated sesquiterpenes 14-hydroxy-9-epi-caryophyllene, cis-muurolol-5-en-4-␣-ol, ␣-cadinol and ledol and the oxygenated monoterpene fenchone, perillyl alcohol, ␣-terpineol and ␤-fenchyl alcohol have been reported as the main chemical constituents of the essential oil of T. riparia (Fernandez et al, 2014;Gazim et al, 2010Gazim et al, , 2014Omolo et al, 2004).…”

Awaiting better times: A quiescence response and adventitious root primordia formation prolong survival under cadmium stress in Tetradenia riparia (Hochst.) Codd

“…Codd belongs to the Lamiaceae family and is a widespread aromatic shrub with a height of approximately 1-3 m occurring throughout eastern and tropical Africa (Gazim et al, 2014). T. riparia occupies a wide range of ecologically contrasting habitats but is often found on hillsides and river banks (Gairola et al, 2009).…”

Bioactive Diterpenoids from Clerodendrum kiangsiense

“…Abietane diterpenoids are a class of tricyclic diterpenoids, and have been isolated from plant species from the taxonomic families Verbenaceae, Lamiaceae, Taxaceae [1][2][3][4]. Clerodendrum is a genus of about 400 species in the family Verbenaceae, which mainly grows in tropical and warm temperate zones including Africa and Southern Asia.…”