Cytotoxic Oxygenated Steroids from the Soft Coral <i>Nephthea erecta</i>

Abstract

A new 10-demethylated steroid, nephtheasteroid A (1), a new 19-oxygenated steroid, nephtheasteroid B (2) as well as five known steroids 3-7 were isolated from the organic extract of a Taiwanese soft coral Nephthea erecta. The structure was determined by means of IR, MS, and NMR techniques. Among these metabolites, 1 is rarely found in steroids possessing a 19-norergostane skeleton. In vitro cytotoxicity study using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that compounds 3 and 4 exhibited cytotoxicity against human chronic myelogenous leukemia (K562), human acute lymphoblastic leukemia (Molt-4), human T lymphoblastoid (Sup-T1), and human leukemic monocyte lymphoma (U937), with IC 50 of 6.5-14.0 µM.

Recent Updates on Corals from Nephtheidae

“…The isolated compound showed a weak cytotoxic activity against the breast cancer MCF-7 cell lines. [20] In another study, analysis of the ethyl acetate fraction of Scleronephthya flexilis THOMSON & SIMPSON, collected by hand using scuba equipment off the coast of Southern Taiwan, has resulted in the isolation of a new pregnane-type steroid, namely 3β-methoxypregna-5,20-diene (23). [21] In the same context, a 19-oxygenated steroid named as nebrosteroid Q (28), in addition to the two 19-norergosterols nebrosteroids R (29) and S (30), was obtained from the acetone extract of N. chabrolii AUDOIN, collected at San-Hsian-Tai, Taiwan, at a depth of 6 m. Nebrosteroids Q-S (28 -30) displayed significant cytotoxicity against mouse lymphocytic leukemia P-388 cell lines with ED 50 of 1.1, 1.2 and 1.0 μg/mL, respectively.…”

“…[22] Nephtheasteroid A (31), a 10-demethylated steroid, and nephtheasteroid B (32) were isolated from the ethyl acetate extract of the Taiwanese soft coral N. erecta KÜKENTHAL that was collected by scuba diving at a depth of 10 m along the -T1) and human leukemic monocyte lymphoma (U937), with IC 50 values higher than 20 μM. [23] Similarly, chemical analysis of the diethyl ether fraction of the soft coral, Litophyton arboreum FORSKÅL has resulted in the identification of a secosteroidal derivative; 13,14seco-22-norergosta-4,24(28)-dien-19-hydroperoxide-3one (35). The specimen was collected from the Red Sea to the North of Jeddah, Saudi Arabia, at a depth of 5 -10 m by scuba divers.…”

“…(20R,22R)-22-Acetoxy-20-hydroxycholesta-1,4-dien-3-one N. sp. [17] 23 3β-Methoxypregna-5,20-diene Scleronephthya flexilis [21] 24 24-methylenecholesta-1,4,22-trien-3-one D. studeri RIDLEY [19] 25 (22E,24S)-24-methyl-19-norcholesta-1,3,5(10),22-tetraen-3-ol D. studeri RIDLEY [19] 26 24-methylene-19-norcholesta-1,3,5(10),22-tetraen-3-ol D. studeri RIDLEY [19] 27 4α-methylergosta-22E,24(28)-dien-3-β-ol N. columnaris [52] 28 Nebrosteroid Q N. chabrolii [22] 29 Nebrosteroid R N. chabrolii [22] 30 Nebrosteroid S N. chabrolii [22] 31 Nephtheasteroid A N. erecta [23] 32 Nephtheasteroid B N. erecta [23] 33 Nephthoacetal N. sp. [12] 34 (22E)-19-Norcholesta-1,3,5(10),22-tetraen-3-ol D. studeri RIDLEY [19] 35 13,14-Seco-22-norergosta-4,24(28)-dien-19-hydroperoxide-3-one L. arboreum [24] 36 3-Oxocholesta-1,4-dien-12β-ol D. gigantea [25] 37 3-Oxocholesta-1,4-dien-20β-ol D. gigantea [25] 38 3-Oxocholesta-1,22-dien-12β-ol D. gigantea [25] 39…”

Bioactive Marine-Derived Compounds as Potential Anticancer Candidates

“…Steroids are considered as major natural compounds in soft corals [1]. A multitude of studies mentioned a wide range of pharmacological activity for these compounds such as anti-inflammatory [2], antifouling [3], and anticancer [2,4,5]. In our previous work, the soft coral Litophyton arboreum total extract has been found to show promising anticancer activity in the ovarian (Hela) and leukemia (U937) cell lines, these findings supported the isolation, and the purification of the most active compounds that showed promising cytotoxic activity and high safety margins reported in our previous study [6].…”

24-Methyl-Cholesta-5,24(28)-Diene-3β,19-diol-7β-Monoacetate Inhibits Human Small Cell Lung Cancer Growth In Vitro and In Vivo via Apoptosis Induction

“…Steroids are some of the commonly-encountered natural products in soft corals of the genus Nephthea [ 9 ]. Previous studies showed that they have a broad range of biological properties, such as anti-inflammatory [ 10 ], anti-fouling [ 11 ], and anti-cancer [ 10 , 12 , 13 ] effects.…”