Ophiobolin Sesterterpenoids and Pyrrolidine Alkaloids from the Sponge‐Derived Fungus Aspergillus ustus

Chemical examination of the fungus Aspergillus ustus isolated from the Mediterranean sponge Suberites domuncula yielded the five new ophiobolin‐type sesterterpenoids 1 – 5 and the two new pyrrolidine alkaloids 6 and 7 , together with the known compound aurantiamine and cerebroside D. The structures of the new compounds were unambiguously elucidated on the basis of extensive spectroscopic‐data analysis (1D‐ and 2D‐NMR, MS, and UV) and comparison with literature data. All compounds were evaluated for their cytotoxicity against murine lymphoma cell line L5178Y.     

New Sterol Derivatives from the Marine Sponge Xestospongia sp.

Chemical examination of a marine sponge Xestospongia sp. resulted in the isolation of 20 sterol derivatives ( 1 – 20 ), including eight new sterols namely aragusterols J – L ( 1 – 3 ), (5α,7α,12β,22E)‐7,12,18‐trihydroxystigmast‐22‐en‐3‐one ( 4 ), (5α,7α,12β,24R)‐ and (5α,7α,12β,24S)‐7,12,20‐trihydroxystigmastan‐3‐one ( 5 / 6 ), and (5α,7α,12β,22E,24R)‐ and (5α,7α,12β,22E,24S)‐7,12,20‐trihydroxyergost‐22‐en‐3‐one ( 7 / 8 ). The structures of new compounds were determined through extensive spectroscopic analyses and chemical conversion. The sterol diversity was mainly characterized by the presence of a cyclopropane unit at side chain, while compound 4 with 18‐hydroxymethyl group was found in stigmasterol family for the first time. Cytotoxic test revealed the inhibitory effects of compounds 1 , 4 , and 17 against human leukemia cell line K562 with IC₅₀ values of 18.3, 24.1, and 34.3 μm , respectively.     

New Sesquiterpene Formamides from the Marine Sponge Axinyssa sp.

Chemical investigation of an extract of the marine sponge Axinyssa sp., collected from the South China Sea, led to the isolation and identification of two new sesquiterpene formamides, (4R*,5R*,10R*)‐4‐formamidoeudesm‐7‐ene ( 1 ) and (4R*,5R*,7S*,10R*)‐4‐formamidoeudesman‐11‐ol ( 2 ), together with the known 4α‐formamidogorgon‐11‐ene ( 3 ). Their structures were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR spectroscopy, high‐resolution ESI‐TOF mass spectrometry, as well as X‐ray single‐crystal diffraction experiments. Possible biosynthetic pathways for 1 – 3 were also proposed. The human nasopharyngeal cancer cell line CNE‐2, human cervical cancer cell line HeLa, and human normal liver cell line L02 were used to examine the cytotoxic activities of 1 – 3 in vitro. As the results, 1 showed significant cytotoxic activity against CNE‐2, HeLa, and L02 cell lines with the IC₅₀ values of 13.8, 7.5, and 38.0 μg/ml, resp.     

海绵Phyllospongia Foliascens中的双高Scalarane二倍半萜

具有Scalarane碳架的二倍半萜以及C-20单甲基化或C-20和C-24双甲基化的Scalarane型高二倍半萜普遍存在于Dictyoceratida科海绵中,我们从同科海绵Phyllospongia foliascens中已分离及测定了5个结构新颖的双高二倍半萜,本文报道另外2个双高二倍半萜phyllohemiketal A(1)和B(2)的分离和结构测定。     

Phorone A and Isophorbasone A, Sesterterpenoids Isolated from the Marine Sponge Phorbas sp

A chemical investigation of a Korean marine sponge, Phorbas sp., yielded unprecedented sesterterpenoids phorone A (1) and isophorbasone A (2) along with ansellone B (3) and phorbasone A acetate (4). Their complete structures were elucidated by the combination of spectroscopic data and chemical manipulation. Phorone A (1) and isophorbasone A (2) have the new "phorane"(5) and "isophorbasane"(6) sesterterpenoid carbon skeletons, respectively. Ansellone B (3) and phorbasone A acetate (4) exhibited potent inhibitory activity on nitric oxide production in RAW 264.7 LPS-activated mouse macrophage cells with IC(50) values of 4.5 and 2.8 μM, respectively.     

海绵Phyllospongia sp.中两个新的Scalarane型二倍半萜

海绵Ｐｈｙｌｌｏｓｐｏｎｇｉａｓｐ．中两个新的Ｓｃａｌａｒａｎｅ型二倍半萜万一千，苏镜娱，曾陇梅，王明焱（中山大学化学系，广州，５１０２７５）关键词海绵，二倍半萜，分离，结构鉴定Ｐｈｙｌｌｏｓｐｏｎｇｉａ属含有丰富二倍半萜的海绵体［１～７］，从这种海...     

Phyllofenone A, a New Scalarane Sesterterpene from the Sponge Phyllospongia Foliascens(Pallas)

The present paper covers the structure of a new sesterterpene, phyllofenone A(1) , isolated from the South China Sea sponge Phyllospongia foliascens. Phyllofenone A is a member of the scalarane class of sesterterpenes with a (C-20, C-24)-bishomo-(C-25)-nortetra-cyclic skeleton. The structure charcterization was based on one- and two-dimensional NMR and mass spectroscopy with the assistance of molecular modeling. Phyllofenone A shows weak antifungal activity against Candida pseudotropicalis.     

Papuamides E and F, Cytotoxic Depsipeptides from the Marine Sponge Melophlus sp

Two known papuamides C (1) and D (2) together with two new depsipeptides, papuamides E (3) and F (4), were isolated from an undescribed sponge of the genus Melophlus collected in the Solomon Islands. The planar structures of the compounds were elucidated on the basis of spectroscopic studies. Papuamides C-F (1-4) showed cytotoxicity against brine shrimp with LD₅₀ values between 92 and 106 μg/mL.     

Two New Ceramides from the Marine Sponge Ircinia fasciculata

A new 4‐sulfated ceramide, ircisulfamide (=N‐[(1S*,2S*,3R*)‐2‐hydroxy‐1‐(hydroxymethyl)‐3‐(sulfooxy)heptadecyl]hexadecanamide; 1 ), and a new glycosphingolipid, ircicerebroside (=(2R*)‐N‐{(1S*,2R*,3E,7E)‐1‐[(β‐D ‐glucopyranosyloxy)methyl]‐2‐hydroxy‐8‐methylheptadeca‐3,7‐dienyl}‐2‐hydroxyeicosanamide; 2 ), were isolated from the aqueous EtOH extract of the marine sponge Ircinia fasciculata (Pallas ). The structures of the new compounds were elucidated on the basis of spectroscopic analysis and by means of chemical methods.     

Phyllactones F and G,Further Bis-Homoscalarane Sesterterpenes from the Sponge Phyllospongia Foliaseens

Introduction In the previous papers, we reported the isolation and structural elucidation of eight 20,24-bishomoscalarane sesterterpenes from the sponge Phyllospongia foliascens collected from Xisha Islands. As a result of our continual investigation of the same sponge     

New Meroditerpenoids from a Taiwanese Marine Sponge Strongylophora Durissima

In addition to strongylophorines 1 (3), 2 (4), 3 (5) and 8 (6), two new meroditerpenoids named strongylophorines 9(1) and 11 (2) were isolated from a Taiwanese marine sponge Strongylophora durissima. The structures of the new compounds were established by spectral methods and chemical derivatizations.     

A New Anthraquinone and Two New Tetrahydroanthraquinones from the Roots of Prismatomeris connata

A new anthraquinone, 4‐hydroxy‐1,2,3‐trimethoxy‐6‐methylanthracene‐9,10‐dione ( 1 ), and two novel tetrahydroanthraquinones, prisconnatanones A and B ( 2 and 3 , resp.), together with 15 known anthraquinones, 4 – 18 , were isolated from the roots of Prismatomeris connata. Their structures were elucidated on the basis of spectroscopic data. Compounds 1 – 18 were evaluated for their cytotoxicity against A549 and LAC human cancer cell lines. Compound 2 and the anthraquinones with free OH groups exhibited activity against the test cell lines.     

New Sesquiterpenes from a Taiwanese Marine Sponge of the Genus Parahigginsia

An undescribed Taiwanese marine sponge of the genus Parahigginsia yielded two new sesquiterpene hydrocarbons-parahigginine ( 1 ) and parahigginone ( 2 ). The structures of the new compounds were established on the basis of NMR spectroscopic and mass spectrometric data. Compounds 1 and 2 exhibited moderate cytotoxicity against murine P-388 and human KB-16, A-549, and HT-29 tumor cells.     

New Sesquiterpenoids from Ligularia duciformis

From the whole plants of Ligularia duciformis, four new sesquiterpenoids, 3β‐acetoxy‐6β‐methoxyeremophila‐7(11),9(10)‐dien‐12,8β‐olide ( 1 ), 3β‐acetoxy‐8α‐hydroxy‐6β‐methoxyeremophila‐7(11),9(10)‐dien‐12,8β‐olide ( 2 ), 3β‐acetoxy‐10β‐hydroxy‐6β,8β‐dimethoxyeremophil‐7(11)‐en‐12,8α‐olide ( 3 ), and 3β‐acetoxy‐6β,8β,10β‐trihydroxyeremophil‐7(11)‐en‐12,8α‐olide ( 4 ) were isolated. Their structures were established by high‐field NMR techniques (¹H,¹H‐COSY, ¹³C‐APT, HMQC, HMBC, and NOESY) and HR‐ESI‐MS analysis, together with comparison of the spectroscopic data with those of structurally related compounds. In addition, the cytotoxicity of the new compounds against human hepatic cancer cells Bel‐7402, human pneumonic cancer cells A‐549, and human colonic cancer cells HCT‐8 were evaluated, the new compounds showed no cytotoxicity against the three tumor cells (all IC₅₀ values >200 μM ).     

New Cytotoxic Triterpenoids from the Aerial Parts of Euphorbia sieboldiana

Phytochemical investigation of the EtOH extract of Euphorbia sieboldiana led to the isolation of four new oleanane‐type triterpenoids, (1β,2α,3β,19β)‐1,2,3,19‐tetrahydroxyolean‐12‐en‐28‐oic acid, (1β,3β,19β)‐1,3,19‐trihydroxyolean‐12‐en‐28‐oic acid, (1β,2α,3β,16β,19β)‐1,2,3,16,19‐pentahydroxyolean‐12‐en‐28‐oic acid, and (1β,2α,3β,19β,23)‐1,2,3,19,23‐pentahydroxyolean‐12‐en‐28‐oic acid, along with 16 known compounds. Their structures were established by extensive 1D‐ and 2D‐NMR, as well as other spectral analyses. Biological evaluation of the four new triterpenoids revealed potent cytotoxic activities against HeLa and Hep‐G2 cells.     

New Casbane Diterpenoids from the Hainan Soft Coral Sinularia Species

Six new casbane diterpenoids, sinularcasbanes G–L ( 1 – 6 , resp.) were isolated from the soft coral Sinularia sp. Their structures were established by extensive spectroscopic analyses, especially 2D‐NMR and HR‐ESI‐MS. The configuration was confirmed by CD analyses and by comparison with data reported in the literature. The compounds were evaluated for cytotoxicity against ten human cancer cell lines (H1975, U937, K562, BGC823, MOLT‐4, MCF‐7, A549, HeLa, HL60, and Huh‐7) and showed no activity.     

New Sesquiterpenes from Ligulariopsis Shichuana

A thorough investigation of Ligulariopsis shichuana afforded five new sesquiterpenes, including 1β,10β‐epoxy‐3α‐angeloyloxy‐9β‐acetoxy‐8α,11β‐dihydroxybakkenolide ( 1 ), 1β,7‐dihydroxy‐3β‐acetoxy‐noreremophil‐6(7),9(10)‐dien‐8‐one ( 2 ), 8α‐hydroxy‐3‐oxoeremophil‐1(2),7(11),9(10)‐trien‐8β(12)‐olide ( 3 ), 1β,10β‐dihydroxy‐3β‐acetoxyeremophil‐7(11),8(9)‐dien‐8(12)‐olide ( 4 ) and 1β,10β‐epoxy‐8,12‐dihydroxy‐3β‐acetoxy‐9β‐angeloyloxyeremophil‐7(11)‐en‐8,12‐disemiketal ( 5 ). Their structures were established by spectroscopic methods and 2D NMR techniques. In addition, bakkenolide ( 1 ) and eremophilenolides ( 5 ) showed antibacterial and cytotoxic activities.     

Two New Polyoxygenated Triterpenoids from Actinidia valvata

Two new polyoxygenated triterpenoids, (2β,3α,6α)‐2,3,6,20,23,30‐hexahydroxyurs‐12‐en‐28‐oic acid ( 1 ) and (2β,3α)‐2,3,20,23,24,30‐hexahydroxyurs‐12‐en‐28‐oic acid O‐β‐D ‐glucopyranosyl ester ( 2 ) were isolated from the roots of Actinidia valvata Dunn . Their structures were elucidated by means of extensive spectroscopic studies. Both compounds showed moderate cytotoxic activity in vitro against the BEL‐7402 and SMMC‐7721 tumor cell lines.     

Evaluating the inhibitory effect of eight compounds from Daphne papyracea against the NS3/4A protease of hepatitis C virus

Abstract

Hepatitis C virus (HCV) infection is a global threat to human health with an estimated 1.75 million new cases in 2015. Our previous studies showed that the ethyl acetate extraction of Daphne papyracea exhibited an inhibitory effect towards the HCV NS3/4A protease and eight compounds were identified from the extract. In this study, we investigated which of the eight compounds was responsible for the inhibitory effect of the extract against the HCV NS3/4A protease. From both molecular docking and enzyme inhibition studies, (+)-usnic acid was shown to be the most active compound and could be used as a lead compound in developing novel anti-HCV agents.