Cytotoxic Activity of Capnellene‐8β, 10α‐Diol Derivatives from a Taiwanese Soft Coral Capnella sp.

Abstract

The sesquiterpene capnellene‐8β, 10α‐diol (1) was isolated from non‐polar extract of the soft coral Capnella sp. Ten acylation products of capnellene‐8β, 10α‐diol were prepared: 10α‐hydroxy‐8β‐O‐benzoylcapnellene (2), 10α‐hydroxy‐8β‐O‐p‐toluoylcapnellene (3), 10α‐hydroxy‐8β‐O‐4‐chlorobenzoyl‐capnellene (4), 10α‐hydroxy‐8β‐O‐2‐furoylcapnellene (5), 10α‐hydroxy‐8β‐O‐2‐thiophenoylcapnellene (6), 10α‐hydroxy‐8β‐O‐4‐fluorobenzoylcapnellene (7), 10α‐hydroxy‐8β‐O‐4‐propylbenzoylcapnellene (8), 10α‐hydroxy‐8β‐O‐cinnamoylcapnellene (9), 10α‐hydroxy‐8β‐O‐4‐nitrobenzoylcapnellene (10), and 10α‐hydroxy‐8β‐O‐4‐anisoylcapnellene (11). The structures of capnellene‐8β, 10α‐diol as well as its derivatives were established through standard spectroscopic analysis. The in vitro cytotoxic activities of the eleven compounds were evaluated against Hela, KB, Daoy, and WiDr human tumor cell lines.

Tricyclic Sesquiterpenes from Marine Origin

“…(+)-Δ 9(12) -Capnellene-8β,10α-diol 32 was also isolated from the soft coral Capnella sp. (Green Island, Taiwan) and from extracts of the Formosan soft coral Paralemnala thyrsoides . Six new capnellene sesquiterpenes 49 – 54 were collected from the soft coral C. imbricata (Green Island, Taiwan) together with (+)- 32 , (+)- 34 , and (−)- 41 , while the tetraol (+)- 55 was characterized from C. imbricata (Laing Island, Indonesia) …”

“…Concerning cervical cancer HeLa cell line, (+)-Δ 9(12) -capnellene-8β,10α-diol 32 , acetylated capnellene (−)- 41 , and (−)-methyl subergorgate 57 provided good activity with ED 50 values between 7.6 and 16.4 μM, while metabolites (−)- 87 , (+)- 195 , and (+)- 310 were found to display weak cytotoxicity (IC 50 = 57.8, 96.2, and 83 μM). Compounds (−)- 18 , (+)- 19 , (+)- 45 – 47 , (−)- 48 , (+)- 110 , (−)- 111 , (+)- 115 , (+)- 122 , (−)- 141 , (+)- 163 , (−)- 164 , (−)- 168 – 172 , (−)- 215 - 217 , (−)- 291 , (+)- 292 , and (−)- 318 exhibited no activity against this cell line (Table ).…”

Marine natural products

“…563 A library of semisynthetic esters of capnellene-8b,10b-diol was prepared and evaluated against a panel of human tumour cell lines; only modest variations in potency were identified. 564 Nardosinane sesquiterpenes 658-660 were isolated from an Indonesian collection of Nephthea sp., 565 while the structurally-related nardosinanols A-I 661-669 and lemnafricanol 670, possessing a novel skeleton, were reported from Kenyan specimens of Lemnalia sp., Paralemnalia clavata, Lemnalia africana and Rhytisma fulvum fulvum. 566 Moderate toxicity to brine shrimp larvae was observed for 663, 667 and 670.…”

Natural Sesquiterpenoids as Cytotoxic Anticancer Agents

“…The sesquiterpene capnellene-8 ,10 -diol 74 (Fig. (22)) was isolated from non-polar extract of the soft coral Capnella sp [34]. Ten acylation products of 74 were prepared.…”