On-line (HPLC-NMR) and Off-line Phytochemical Profiling of the Australian Plant, Lasiopetalum macrophyllum

Abstract

On-line (HPLC-NMR) and off-line (HPLC, NMR and MS) methodologies were used to profile the constituents present in the crude extract of Lasiopetalum macrophyllum. On-flow and stop-flow HPLC-NMR supported the presence of trans-tiliroside and permitted partial identification of cis-tiliroside and 4′methoxy-trans-tiliroside. Off-line isolation led to the unequivocal identification of four flavanoid glycosides including a new structural derivative, 4′-methoxycis-tiliroside. This is the first report of flavonoid glycosides occurring in this plant genus. In addition, a number of structure revisions have been proposed for previously reported flavonoid glycosides that were incorrectly assigned.

Studies on Cytotoxic Constituents from the Leaves of Elaeagnus oldhamii Maxim. in Non-Small Cell Lung Cancer A549 Cells

“…Yellowish powder, 1 H-NMR (500 MHz, CD 3 COCD 3 ): δ 12.37 (1H, br s , OH), δ 8.09 (2H, d , J = 8.8 Hz, H-2' and H-6'), δ 7.68 (2H, d , J = 8.6 Hz, H-2''' and H-6'''), δ 6.92 (2H, d , J = 8.8 Hz, H-3' and H-5'), δ 6.78 (2H, d , J = 8.6 Hz, H-3''' and H-5'''), δ 6.78 (1H, d , J = 12.9 Hz, H-7'''), δ 6.47 (1H, br s , H-8), δ 6.27 (1H, br s , H-6), δ 5.62 (1H, d , J = 12.9 Hz, H-8'''), δ 5.17 (1H, d , J = 7.3 Hz, H-1''), δ 4.28 (1H, dd , J = 11.9, 1.8 Hz, H-6β''), δ 4.17 (1H, dd , J = 11.9, 6.0 Hz, H-6α''), δ 3.55 (1H, m , H-2''), δ 3.55 (1H, m , H-5''), δ 3.49 (1H, t , J = 8.9 Hz, H-4''), δ 3.41 (1H, d , J = 9.3 Hz, H-3''). The above data were identical to the literature data [45].…”

“…The 1 H- and 13 C-NMR spectra of the 25 compounds isolated in present study (Table 1, Table 2, Table 3 and Section 3.4) including oleanolic acid ( 1 ) [32], 3- O -( Z )-coumaroyl oleanolic acid ( 2 ) [33], 3- O -( E )-coumaroyl oleanolic acid ( 3 ) [34], 3- O -caffeoyl oleanolic acid ( 4 ) [35], ursolic acid ( 5 ) [36], 3- O -( Z )-coumaroyl ursolic acid ( 6 ) [35], 3- O -( E )-coumaroyl ursolic acid ( 7 ) [36], 3- O -caffeoyl ursolic acid ( 8 ) [37], 3β, 13β-dihydroxyolean-11-en-28-oic acid ( 9 ) [37], 3β, 13β-dihydroxyurs-11-en-28-oic acid ( 10 ) [38], uvaol ( 11 ) [39], betulin ( 12 ) [40], lupeol ( 13 ) [41], kaempferol ( 14 ) [42], aromadendrin ( 15 ) [43], epigallocatechin ( 16 ) [44], cis -tiliroside ( 17 ) [45], trans -tiliroside ( 18 ) [46], isoamericanol B ( 19 ) [47], trans - p -coumaric acid ( 20 ) [47], protocatechuic acid ( 21 ) [48], salicylic acid ( 22 ) [49], trans- ferulic acid ( 23 ) [50], syringic acid ( 24 ) [51] and 3- O -methylgallic acid ( 25 ) [52] were compared with the spectral data reported in the literature and their structures were thus confirmed.…”

Antimicrobial and antioxidant activities of triterpenoid and phenolic derivatives from two Cameroonian Melastomataceae plants: Dissotis senegambiensis and Amphiblemma monticola

“…1 ). Compounds obtained from D. senegambiensis were identified as β -amyrin palmitate ( 1 ) [ 28 ], α -amyrin acetate ( 2 ) [ 29 ], ursolic acid ( 3 ) [ 30 ], sitosterol-3-O- β -D-glucopyranoside ( 4 ) [ 31 ]; vitexin ( 5 ) [ 32 ] and trans -tiliroside ( 6 ) [ 33 ]. From A. monticola , compounds were identified as 3,4′-di- O -methylellagic acid ( 7 ) [ 34 ], dimethyl 4,4′,5,5′,6,6′-hexahydroxybiphenyl-2,2′-dicarboxylate ( 8 ) [ 35 ], lupeol ( 9 ) [ 36 ], ellagic acid ( 10 ) [ 16 ], 3-hydroxy-4,5-dimethoxybenzoic acid ( 11 ) [ 37 ], 3- O -methylellagic acid 4′- O - β -D-xylopyranoside ( 12 ) [ 38 ], oleanolic acid ( 13 ) [ 16 ], and amphiblemmone A ( 14 ) [ 13 ].…”

Dereplication strategies in natural product research: How many tools and methodologies behind the same concept?

“…Another advantage is that although dereplication does not provide original information on novel chemical structures, previously known compounds can still be identified in genus or species in which they are not a priori expected. For instance, flavonoid glycosides already known in a range of plant species were identified for the first time in the genus Lasiopetolum by using a LC/NMR-based DEREP1 procedure (Timmers and Urban 2011). Of course, the efficiency of such dereplication approach strongly depends on the quality of spectral libraries.…”