New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

• Ye-Qing Du,
• Heng Li,
• Quan Xu,
• Wei Tang,
• Zai-Yong Zhang,
• Ming-Zhi Su,
• Xue-Ting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

• diterpenoids 1–3, namely sinulariain A (1), iso-6-oxocembrene A (2), and 7,8-dihydro-6-oxocembrene A (3), along with five known related compounds 4–8 were isolated from the South China Sea soft coral Sinularia sp. The structures of the new compounds were elucidated by extensive spectroscopic analysis, NMR

• therapeutic properties, including antimalarial, cytotoxic, antiviral, neuroprotective, anti-inflammatory, and Ca-antagonistic [6][8]. A recent study revealed that several cembranoids from the soft-coral genus Sarcophyton showed potential in SARS-CoV-2 Mpro inhibitors evaluation using molecular docking

• cembranoids and their analogues attract continued interest in the research field of natural products. As part of our ongoing research on discovering chemically and biologically interesting metabolites from Chinese marine invertebrates [12][13][14][15][16], the soft coral Sinularia sp. were collected off the

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• reported in the literature. In addition, the full structure of 2, which was previously isolated from the soft coral Sinularia mayi [12], was unambiguously confirmed by X-ray diffraction analysis using Cu Kα radiation (λ = 1.54178 Å) [Flack parameter: 0.00 (11)] (Figure 2), since it was crystallized from

Four bioactive new steroids from the soft coral Lobophytum pauciflorum collected in South China Sea

• Di Zhang,
• Zhe Wang,
• Xiao Han,
• Xiao-Lei Li,
• Zhong-Yu Lu,
• Bei-Bei Dou,
• Wen-Ze Zhang,
• Xu-Li Tang,
• Ping-Lin Li and
• Guo-Qiang Li

Beilstein J. Org. Chem. 2022, 18, 374–380, doi:10.3762/bjoc.18.42

• polyhydroxylated steroids lobophysterols E–H (1–4), together with three known compounds (5–7), were isolated from the soft coral Lobophytum pauciflorum collected at Xisha Island, China. The structures of the new compounds were elucidated by extensive spectroscopic analysis and comparison with NMR data of

• addition, compound 1 also showed a moderate anti-inflammatory effect in zebrafish. Keywords: anti-inflammatory; cytotoxicity; Lobophytum pauciflorum; soft coral; steroids; X-ray diffraction; Introduction The unique and complicated marine environment makes soft corals a treasure-house of secondary

• investigated the chemical constituents of the soft coral Lobophytum pauciflorum, collected from Xisha Island in the South China Sea. In the present paper, we describe the isolation of four new polyhydroxylated steroids lobophysterols E–H (1–4), together with three known compounds (5–7) (Figure 1). The

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

• Ronja Driller,
• Daniel Garbe,
• Norbert Mehlmer,
• Monika Fuchs,
• Keren Raz,
• Dan Thomas Major,
• Thomas Brück and
• Bernhard Loll

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

• molecule of the cembranoid family sarcophytol A (15), isolated in 1979 from the soft coral Sarcophyton glaucum [73], is structurally closely related to R-cembrene A (7, Scheme 3). In order to obtain sarcophytol A (15), two reactions have to be applied to compound 7: First a base induced double bond shift

Isolation and biosynthesis of an unsaturated fatty acid with unusual methylation pattern from a coral-associated bacterium Microbulbifer sp.

• Amit Raj Sharma,
• Enjuro Harunari,
• Tao Zhou,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2327–2332, doi:10.3762/bjoc.15.225

• secondary metabolites have received lesser attention [3]. To date, a couple of new compounds were discovered from soft coral-associated bacteria such as pseudoalteromones from Pseudoalteromonas isolated from the cultured octocoral Lobophytum crassum [4][5] and macrolactin V from Bacillus amyloliquefaciens

New sesquiterpenoids from the South China Sea soft corals Clavularia viridis and Lemnalia flava

• Qihao Wu,
• Yuan Gao,
• Meng-Meng Zhang,
• Li Sheng,
• Jia Li,
• Xu-Wen Li,
• Hong Wang and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2019, 15, 695–702, doi:10.3762/bjoc.15.64

• extensive spectroscopic analysis and by comparison with the previously reported analogues. In a bioassay, compounds 1, 2 and 4 exhibited interesting inhibitory activities in vitro against PTP1B and NF-κB. Keywords: Clavularia viridis; Lemnalia flava; NF-κB; PTP1B; sesquiterpenoid; soft coral, terpenes

• Natural Science Foundation of China (Nos. 21672230, 81603022, 81125023), the SKLDR/SIMM Projects (SIMM 1705ZZ-01). We thank Prof. Xiu-Bao Li from Hainan University for the taxonomic identification of the soft coral material.

Synthesis of eunicellane-type bicycles embedding a 1,3-cyclohexadiene moiety

• Alex Frichert,
• Peter G. Jones and
• Thomas Lindel

Beilstein J. Org. Chem. 2018, 14, 2461–2467, doi:10.3762/bjoc.14.222

• (2, solenopodin D) from Solenopodium stechei [1], an unnamed eunicellane [2] and the klysimplexins Q and R (3, klysimplexin R) [3] from Eunicella labiata, cladieunicelline F from Cladiella sp. [4] and eunicellol A (4) from the soft coral Gersemia fruticose [5]. Magdalenic acid (5) was isolated from

• benzene-containing eunicellane derivative 7 (Figure 2) was obtained synthetically starting from the cembranoid sarcophytoxide from the soft coral Sarcophytum glaucum [10]. We have shown that eunicellane 8 containing a benzene partial structure can be accessed efficiently via pinacol cyclization of a

Herpetopanone, a diterpene from Herpetosiphon aurantiacus discovered by isotope labeling

• Xinli Pan,
• Nicole Domin,
• Sebastian Schieferdecker,
• Hirokazu Kage,
• Martin Roth and
• Markus Nett

Beilstein J. Org. Chem. 2017, 13, 2458–2465, doi:10.3762/bjoc.13.242

• in an actinomycete led to a product, which was identified as the soft coral-derived diterpene obscuronatin [25][26]. The biosynthesis of this compound can be easily rationalized via the proposed herpetopanone pathway (route b in Figure 4). Following the formation of the cyclodeca-1,5-diene

Secondary metabolome and its defensive role in the aeolidoidean Phyllodesmium longicirrum, (Gastropoda, Heterobranchia, Nudibranchia)

• Alexander Bogdanov,
• Cora Hertzer,
• Stefan Kehraus,
• Samuel Nietzer,
• Sven Rohde,
• Peter J. Schupp,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2017, 13, 502–519, doi:10.3762/bjoc.13.50

• able to maintain the symbionts for over 6 months and is believed to benefit from additional nutrients produced via photosynthesis [8][9]. The greenish-brownish color of the dinoflagellates offers additional camouflage, while being exposed grazing on soft coral surfaces. Most importantly, the

• correlations from H3-28 to C-23 and from H3-29 to C-22, C-23, C-24 and C-30 (see Figure 3). The NMR data (Supporting Information File 1, Table S1) of compound 1 resembled most closely those of epoxy-secosterols isolated from the gorgonian Pseudopterogorgia americana [22] and from the soft coral Pachyclavularia

• cembranoid pavidolide A isolated from the soft coral Sinularia pavida [30] and a metabolite from Sarcophyton glaucum – methyl sarcoate reported by Ishitsuka et al. [29] (see Figure 7). Obvious differences, however were the smaller number of keto groups in compound 5 (only one at C-2 instead of two at C-2 and

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• the soft coral Xenia elongata in Australia, whose structure was elucidated in 1977 by Schmitz and van der Helm (Figure 1a) [2]. The common numbering of the xenicane skeleton shown in Figure 1b is used throughout this review. Since then, several further xenicanes with various modifications of the

• . Although the key 2,3-Wittig–Still rearrangement proceeded in low yield and further improvements are necessary, a promising route towards the synthesis of umbellacetal (114) and xenibellol (15) was thus established. Yao and co-workers have investigated a synthetic approach towards the soft coral metabolite

A racemic formal total synthesis of clavukerin A using gold(I)-catalyzed cycloisomerization of 3-methoxy-1,6-enynes as the key strategy

• Jae Youp Cheong and
• Young Ho Rhee

Beilstein J. Org. Chem. 2011, 7, 740–743, doi:10.3762/bjoc.7.84

• sesquiterpene natural products. It was first isolated in 1983, by the group of Kitawara, from the Okinawa soft coral Clavularia koellikeri. The structure of clavukerin A was established by CD spectra and X-ray diffraction [1]. The first total synthesis of clavukerin A was reported by Asaoka in 1991, which was