Records of Natural Products Articles

A growing evidence indicates that the endophytic fungus Aspergillus is one of rich sources of natural products with a broad spectrum of biological activities. Up to now, 162 secondary metabolites had been structurally identified from 11 endophytic Aspergillus spp. and 67 of them were shown to have strong bioactivities with potential application in drug discovery. This review focuses on biology and chemistry of endophytic Aspergilli, especially their bioactive secondary metabolites. Covering: 2004 to 2014.

A new phenylpropanoid derivative, named carthamusin A (1), along with two known compounds β -daucosterol (2) and stigmasterol (3) were isolated fromCarthamus tinctorius L. The structures were elucidated by extensive 1D and 2D (HMBC, HMQC, 1H- 1H COSY) NMR and MS spectroscopy.

Essential oils from fresh parts of Etlingera brevilabrum Valeton (Zingiberaceae) including rhizome, stolon, stem, and leaves were hydrodistilled, and studied for their chemical composition, antioxidant, and antibacterial activity. Characterization by GC-FID and GC-MS showed monoterpene hydrocarbons dominated the oils of the leaves and stems (57.3 and 73.4%) with oxygenated monoterpenes were dominant in the stolon and rhizomes (40.4 and 53.6%). The major compounds of the rhizome oil were perilla aldehyde (19.6%) and bornyl acetate (17.6%); the stolon oil, β-pinene (30.6%) and p-cymen-7-ol (25.0%); the stem oil, δ-3-carene (43.2%) and α-thujene (17.7%); and the leaf oil, α-thujene (38.1%) and p-cymen-7-ol (8.0%). The rhizome oil showed the highest antioxidant effects with IC 50 = 1236.54±12.83 µ g/mL in the DPPH radical scavenging activity, 22.76% inhibition in the β-carotene bleaching test at 1000 µ g/mL, and IC 50 = 878±16.54 µ g/mL in the ferrous ion chelating ability. Antibacterial activity demonstrated by disc diffusion assay showed that the rhizome, stem and leaf oils inhibited Staphylococcus aureus and MRSA but not Bacillus subtilis and Bacillus thuringiensis. For Gram negative bacteria, the rhizome oil prevented the growth of Proteus mirabilis ; the stem oil inhibited Escherichia coli and Proteus vulgaris ; and the leaf oil was active against E. coli , P. vulgaris , and P. mirabilis .

Alchornea castaneifolia is a tree growing commonly in several South American countries. It is best known under its Peruvian name Iporuru. The leaves are being used as a folk remedy against numerous symptoms associated with pain and inflammation. It has a reputation for being a tonic and booster of male libido. In this study, using a combination of chromatographic techniques, we isolated phenolic constituents present in leaves, and elucidated their structures using MS and NMR techniques. The isolated and characterized compounds were myricetin glucoside, myricetin galactoside, proanthocyanidin A1 and A2, epicatechin, gallic acid, shikimic acid, putranjivain A, elaeocarpusin and never before isolated methyl ester of repandusinic acid A.

Chemical and biological investigations were carried out to evaluate the composition and anti-microbial potential of a rare Artemisia species viz. Artemisia stricta Edgew. f. stricta Pamp. essential oil for the first time. GC and GC/MS analysis resulted in the identification of 27 compounds, which constituted 93.2% volatile constituents of the oil. The major constituents were capillene (41.6%), spathulenol (14.6%) and β-caryophyllene (13.4%). The oil was also assayed to determine its antimicrobial potential against eight bacterial and six fungal strains. The oil exhibited both antifungal and antibacterial activities. Among bacteria, the oil was most effective against Staphylococcus epidermidis (MIC 0.625 mg/mL ) followed by Staphylococcu. Aureus (MIC 1.25 mg/mL ). While among fungi, the oil was most effective against Aspergillus flavus followed by Aspergillus niger and Sporothrix schenckii with MIC as low as 0.625 mg/mL.

Applying the concept of ethnobotany, plant extract was taken into consideration as an alternative to chemicals synthesis of silver nanoparticle. The extracts from the chilli seeds were used to synthesize silver nanoparticles (AgNPs). In this study two species of chilli, Capsicum annuum and Capsicum frutescens, have been used to analyse the characteristics of the bio-active compounds found in their seeds. Analysis of the bioactive compound was performed by using Soxhlet extraction with solvents followed by Thin Layer Chromatography (TLC), High Performance Liquid Chromatography (HPLC) and GC-MS. Furthermore, green synthesis of nanoparticles with chilli extracts was carried out using silver nitrate to detect its antimicrobial activity. The characterizations of both the nanoparticles were carried out using UV-Vis Spectroscopy, Atomic Force Microscopy (AFM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) and energy Dispersive X-Ray Spectroscopy (EDX). Antimicrobial activity against clinical pathogens and the antioxidant assay using DPPH and FRAP assays were performed. The cytotoxicity effects on osteosarcoma cell lines were also evaluated with the synthesized AgNPs.

The volatile fraction of the brown alga Cystoseira sedoides (Desfontaines) C.Agardh is prepared from the crude extract through the following three extraction methods: Hydrodistillation (HD), focused microwave assisted hydrodistillation (FMAHD) and supercritical fluid extraction (SFE). The volatile fractions are analyzed by gas chromatography-flame ionization detector-mass spectrometry (GC-FID-MS), the chemical components are identified on the basis of the comparison of their retention indices with literature and their mass spectra with those reported in commercial databases. The chemical composition of the volatile fractions obtained by different extraction techniques fall into three major chemical classes: fatty acids and derivatives, sesquiterpenes, and hydrocarbons and derivatives. Others Compounds belonging to different chemical classes are found in that chemical composition.

The fruit of Aristotelia chilensis is considered a “super fruit” due to its high concentration of polyphenols displaying exceptional antioxidant capacities ORAC. From maqui berries have been reported several anthocyanins and glycosylated flavonoids, those benefits increase the attention to restudy the plant. From the leaves of A. chilensis several indole alkaloids have been reported, we in addition to aristoteline, aristone, aristoquinoline and 3-fromylindole report the spectroscopic elucidation of 8-oxo-9-dehydromakomakine (1), hobartine (2) and a new alkaloid named 8-oxohobartine (3). Compound 1 to 3 did not show bactericidal activity against E. coli and S. aureus till 200 μg.

The essential oil from the leaves of Murraya alata Drake was extracted by hydrodistillation and analyzed by GC-MS. A total of 70 components were identified, accounting for 93.7% of the oil composition. The major compound is a -cadinol (18.9%), followed by a -muurolol (10.0%), trans -prenyl limonene (7.7%), germacra-4(15),5,10(14)-trien-1- a -ol (6.0%) , and cedryl acetate (5.4%). M. alata oil was characterized by a high content of sesquiterpenes (91.2%), with cadinene-type being the most representative compounds . The structural diversity of sesquiterpenes as well as their chemotaxonomic significance was discussed. In addition, M. alata oil showed moderate in vitro antioxidant and cytotoxic effects.

Three a -amyrine type triterpenes (1-3) in addition to oleanolic acid (4) and six known flavonoids, namely apigenin (5) and its 7-O- b -D-glucuronide (9), 5,6,4 ¢ -trihydroxy-7,3 ¢ -dimethoxy-flavone (6), cirsilineol (7) , sudachitin (8) and cilicione-b (10) were isolated from the dichloromethane extract of the pericarps of Juglans regia . The structures of the compounds were established on the basis of spectroscopic analyses (UV, IR, HRESIMS and 1D & 2D NMR). Compounds 2, 3 and 6-10 were isolated from J. regia for the first time . To the best of our knowledge, compound 3 is a new natural product. All isolated compounds, as well as the dichloromethane extract were evaluated for their cytotoxic activity against the human cancer cell lines, MCF-7, HCT-116, HeLa, Κ562, Raji and THP-1. Compounds (1) and (5) showed the most potent anticancer activity against the cancer cells assessed. Interestingly, the concentration of compound (5) that was cytotoxic to cancer cells did not induce human peripheral blood mononuclear cell apoptosis. These results suggest that the structure of compound (5) may eventually serve as a lead for developing novel anticancer drugs with limited side effects against normal cells.

The essential oils (EOs) from the leaves and the flowers of Smyrnium olusatrum L. , growing wild in the island of Cephalonia (Greece), were analyzed by GC-FID and GC-MS. Fifty nine constituents, which accounted for 90.3% (fl) and 97.1% (lvs) of the oils, were identified. Furanodiene, g ermacrone and furanoeremophil-1-one were the major constituents in both essential oils; they were also isolated from the flowers essential oil and identified using spectroscopic methods, ie. 1D and 2D NMR, GC-MS . In addition b -myrcene ( 11.7%) and b -phellandrene (5.2%) were main constituents in the essential oil of the leaves. The essential oils and the pure isolates were evaluated for antifungal activity against Aspergillus fumigatus , A. versicolor, A. ochraceus, A. niger, Trichoderma viride, Penicillium funiculosum, P. ochrochloron, P. verucosum var. cyclopium by using the microdilution method and proved to possess significant antifungal effect. Among them, (+) furanoeremophil-1-one was particularly active with MIC values in the range of 0.0008-0.125 mg/mL and MFC values of 0.025-0.050 mg/mL and proved more effective than the commercial mycotics ketoconazole and bifonazole used as positive controls.

Phytochemical investigation of the ethyl acetate extract of the fruiting bodies from the basidiomycete Piptoporus betulinus led to the isolation of a new bioactive lanostane triterpene identified as 3 b -acetoxy-16-hydroxy-24-oxo-5α-lanosta-8- ene-21-oic acid (1). In addition, ten known triterpenes, polyporenic acid A (5), polyporenic acid C (4), three derivatives of polyporenic acid A (8, 10, 11), betulinic acid (3), betulin (2), ergosterol peroxide (6), 9,11-dehydroergosterol peroxide (7), and fomefficinic acid (9), were also isolated from the fungus. All isolated compounds were tested for antimicrobial activity against some Gram-positive and Gram-negative bacteria as well as against a fungal strain. The new triterpene and some of the other compounds showed antimicrobial activity against Gram-positive bacteria.

A methanol extract of the roots of Stemona tuberosa (Stemonaceae) significantly inhibited lipopolysaccharide-induced nitric oxide production in murine BV2 microglial cells. Eight alkaloids tuberostemonine K (1), neotuberostemonine (2), oxotuberostemonine (3), bisdehydroneotuberostemonine (4), epibisdehydrotuberostemonine J (5), bisdehydrotuberostemonine (6), tuberostemoninol (7), and neostenine (8) were isolated from the methanolic extract using bioactivity-guided fractionation. Among them, compounds 4, 5 and 6 showed significant inhibitory effect on lipopolysaccharide-induced nitric oxide production in BV2 microglia at 100 m M.

An investigation of n-BuOH extract of Dendrobium aurantiacum var. denneanum stems has led to the isolation of a new 8′,9′-dinor 8,4′-oxyneolignane glucoside, (–)-(7 S ,8 S )-4-hydroxy-3,3′,5,5′-tetramethoxy-8′,9′-dinor - 8,4′-oxyneolign a -7,9-diol- 7 ′-al 4-O-β-D-glucopyranoside (1), and four phenylpropanoid glycosides (2– 5 ) . The structures of the isolated compounds were elucidated by chemical and spectroscopic methods . This is the first report of norlignane from the genus Dendrobium.

Chemical investigation of the sponge Callyspongia sp . from the South China Sea afforded one new diketopiperazine , cyclo-(R-Pro-6-hydroxyl-S -Ile) (1), along with six known d iketopiperazines : staphyloamide A (2), cyclo- (S-Pro-S-Phe) (3), cyclo-(R-Pro-R-Phe) (4), cyclo- (S-Pro-R-Leu) (5 ) , cyclo-(S-Pro-R-Ala) (6), cyclo-(R-Tyr-R-Phe) (7), and three known tryptophan-derived alkaloids: C 2-α-D-mannosylpyranosyl-tryptophan (8), (1 R , 3 S )-1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylic acid (9), and (1R,3R)-1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylic acid (10) . The structures were determined on the basis of NMR and MS analysis , and the absolute configuration was determined by comparison of the optical rotation with the known compounds. This is the first report of compounds 1, 2 , 8–10 from the sponge Callyspongia . Cyclo- (S-Pro-R-Leu) (5 ) , and cyclo-(S-Pro-R-Ala) (6) exhibited antifouling activity against cyprid larvae of the barnacle with the LC 50 values of 3.5 μg/cm 2 and 6.0 μg/cm 2, respectively .

In search of new natural fatty acid sources, extract of 10 different Turkish Klasea species were studies. Fatty acids of Klasea species were studied by GC and GC-MSD. Oleic acid (4.8-45.8%), palmitic acid (15.6-51.8%), linoleic acid (0.3-45.5%), palmitoleic acid (0.8-28.4%) and linolenic acid (15.6-34.6%) were the main fatty acids elucidated. All extracts were also subjected to acetylcholinesterase, butyrylcholinesterase, tyrosinase, β-carotene-linoleic acid, DPPH • scavenging, CUPRAC and ferrous ion-chelating ability activities. Total flavonoid and phenolic contents were determined as quercetin and pyrocatechol equivalents. All extracts showed significant antioxidant activity in all tests, except hexane extracts of K. serratuloides and K. cerinthifolia that showed weak inhibition against BChE and AChE. The hexane extract of K. coriaceae and methanol extract of K. serratuloides exhibited notable tyrosinase inhibitory activity.