Macki Kaloga

Abietane diterpenoids and triterpenoic acids from Salvia cilicica and their antileishmanial activities

Bioguided-fractionation of an acetone extract of the roots of Salvia cilicica (Lamiaceae) led to isolation of two new diterpenes, 7-hydroxy-12-methoxy-20-nor-abieta-1,5(10),7,9,12-pentaen-6,14-dione and abieta-8,12-dien-11,14-dione (12-deoxy-royleanone), together with oleanolic acid, ursolic acid, ferruginol, inuroyoleanol and cryptanol. Their structures were determined spectroscopically, which included HREIMS and 2D NMR spectroscopic analysis. The new abietane derivatives showed appreciable in vitro antileishmanial activity against intracellular amastigote forms of both Leishmania donovani (IC(50) values of 170 and 120 nM, respectively) and Leishmania major (IC(50) values of 290 and 180 nM, respectively). The triterpenoic acids were found to be potently active against amastigote (IC(50) values of 7-120 nM) and moderately active against promastigote stages (IC(50) values of 51-137 nM) of the two Leishmania species.

Flavonoid sulfates from the Convolvulaceae

Abstract A novel flavonoid, quercetin 7-methyl ether-3,3′-disulfate ( 5 ), was obtained from the roots of Argyreia mollis , together with the known compounds quercetin 7-methyl ether-3-sulfate ( 4 ) and kaempferol 7-methyl ether-3-sulfate ( 2 ). Two further new flavonoid sulfates, quercetin 3,7-dimethyl ether-4′-sulfate ( 6 ) and quercetin 3′,4′,7-trimethyl ether-3-sulfate ( 8 ), were isolated from the aerial vegetative parts of Ipomoea regnellii , together with the known compound kaempferol 4′,7-dimethyl ether-3-sulfate ( 3 ). This is the first report on sulfated flavonoids in the Convolvulaceae family and, furthermore, the presence of flavonoids in A. capitata , A. mollis , I. reticulata and I. regnellii is reported for the first time.

Occurrence of loline alkaloids in Argyreia mollis (Convolvulaceae)

Abstract N -Formylloline was isolated from roots of Argyreia mollis . This is the first identification of a 1-aminopyrrolizidine alkaloid (loline alkaloid) in a species of the Convolvulaceae. Lolines are only known from the genus Adenocarpus (Fabaceae) and certain grasses (e. g. Festuca ) infected with endophytic fungi. A GC–MS analysis revealed N -formylloline to be present in roots and aerial vegetative plant parts. It is accompanied by three congeners (i. e. loline, N -methylloline and N -propionylnorloline) and simple pyrrolidine alkaloids such as hygrine and its derivatives as well as tropan-3β-ol. Lolines could not be detected in Argyreia capitata , A. hookeri , A. nervosa and numerous species of 14 other convolvulaceous genera.

Pyrrolizidine alkaloids of Ipomoea hederifolia and related species

Abstract The common necine base of the novel pyrrolizidine alkaloids (ipangulines) isolated recently from Ipomoea hederifolia is not turneforcidine but its 1β-epimer, platynecine. Three novel ipangulines were isolated from the aerial parts of I. hederifolia and identified as 9- O -[2-hydroxy-3-(2-acetoxy)-2-methylbutyryl]-7- O -salicyloylplatynecine (ipanguline B 2 ), 9- O -[2-hydroxy-3-(2-methylbutyryloxy)-2-methylbutyryl]-platynecine (ipanguline D 10 ) and 9- O -salicyloylplatynecine (ipanguline D 11 ). Comprehensive GC-mass spectrometric analysis also revealed a great variety of >38 platynecine monoesters and diesters. They are classified as ipangulines A (diesters with one phenylacetic acid moiety), ipangulines B (diesters with one salicylic acid moiety), ipangulines C (diesters with two aliphatic moieties) and ipangulines D (either 7- or 9-monoesters). In shoot tips and young leaves, total ipangulines concentrations are up to 0.45% (on dry wt basis). The ipangulines are stored as tertiary alkaloids and not as N -oxides. Seeds of different provenance showed similar alkaloid patterns. Taxonomically related species, such as I. neei and I. × perigrenium , also contain platynecine esters in their vegetative tissues.

Ipangulines, the first pyrrolizidine alkaloids from the convolvulaceae

Abstract Four novel pyrrolizidine alkaloids were isolated from Ipomoea hederifolia. It could be shown by spectroscopic methods that the compounds represent two pairs of isomeric turneforcidine diesters with either erythro- or threo-2,3-dihydroxy-2-methyl-butyric acid as the acyl moiety at C-9 OH. One pair (ipanguline A/isoipanguline A) is characterized by phenylacetic acid as the second acyl component (at C-7 OH), the other (ipanguline B/isoipanguline B) includes a salicylic acid moiety in this position. The distribution pattern shows the occurrence of the A compounds in the seeds and of the B compounds in the roots, respectively, with all four alkaloids in the aerial parts.

Unusual Coumarin Patterns of Pelargonium Species Forming the Origin of the Traditional Herbal Medicine Umckaloabo

Abstract The coumarin patterns of Pelargonium sidoides DC. and Pelargonium reniforme CURT., forming the origin of the herbal medicine “umckaloabo”, were analysed and compared for therapeutic equivalence. For both species, members of tri- and tetraoxygenated coumarins almost exclusively were present in the respective metabolic pools. However, the roots of P. sidoides and P. reniforme expressed conspicuously distinct coumarin variations, with umckalin, its 7-O-methyl ether, 7-acetoxy-5,6-dimethoxycoumarin, 6,8-dihydroxy-7-methoxycoumarin, 6,8-dihydroxy-5,7-tetramethoxycoumarin, artelin and three unique coumarin sulfates as uncommon metabolites of this class of secondary products of P. sidoides. Furthermore, the highly oxygenated but known coumarins fraxinol, isofraxetin and fraxidin were associated with the new 8-hydroxy-5,6,7-trimethoxycoumarin as representatives of P. reniforme. Of the twelve identified coumarins only the two species shared the ubiquitous scopoletin and the unique 6,7,8-trihydroxycoumarin. From the oxygenation patterns it is evident that the majority of these Pelargonium coumarins match the recently established basic structural requirements for marked antibacterial activity, i.e. the presence of a methoxy function at C-7 and an OH group at either the C-6 or C-8 position. The current data on the coumarin profiles of each Pelargonium species also indicate a previous erroneous identification of the plant material claimed to be P. reniforme. Absence and presence of umckalin and its 7-O-methyl ether defines P. reniforme and P. sidoides, respectively.

Aliphatic pyrrolidine amides from two tropical convolvulaceous species

Abstract Seven aliphatic pyrrolidine amides with branched and linear saturated C 15 –C 19 acyl moieties were detected in vegetative plant organs of Ipomoea aquatica and Merremia quinquefolia as well as in seeds of M . quinquefolia by GC–MS analysis. One of the compounds was isolated from both species and characterized as 1-(14-methylhexadecanoyl)pyrrolidine, a new natural product. The presence of 1-hexadecanoylpyrrolidine and 1-octadecanoylpyrrolidine was confirmed by comparison of their GC–MS data with those of synthesized compounds.

Tropane alkaloids with a unique type of acyl moiety from two Convolvulus species

Abstract An investigation of the roots of Convolvulus siculus and C. sabatius ssp. mauritanicus afforded two new tropan-3 α -ol esters named consiculine and consabatine and the known base merresectine B (3). The acyl residues of the new alkaloids are formed by consiculic acid ( = 1 β ,2 α -dihydroxy-5-prenyl-cyclohex-5-en-4-one carboxylic acid) and its 2-deoxy derivative, respectively.

Jacpaniculines the first lignanamide alkaloids from the convolvulaceae

Abstract Two new lignanamides were isolated from fruits of Jacquemontia paniculata var. paniculata . It could be shown that these compounds represent a p