Shahina Fayyaz

Pentacyclic triterpenoids from the aerial parts of Lantana camara and their nematicidal activity.

Two new olean‐12‐ene triterpenoids, camarolic acid (1) and lantrigloylic acid (2), have been isolated from the aerial parts of Lantana camara, along with ten known triterpenes, namely, camaric acid, lantanolic acid, lantanilic acid, pomolic acid, camarinic acid, lantoic acid, camarin, lantacin, camarinin, and ursolic acid. The new compounds have been characterized as 3,25‐epoxy‐3α‐hydroxy‐22β‐{[(S)‐3‐hydroxy‐2‐methylidenebutanoyl]oxy}olean‐12‐en‐28‐oic acid (1) and 3,25‐epoxy‐3α‐hydroxy‐22β‐[(3‐methylbut‐2‐enoyl)oxy]olea‐9(11),12‐dien‐28‐oic acid (2) through spectroscopic studies and a chemical transformation. Seven of the constituents, namely pomolic acid, lantanolic acid, lantoic acid, camarin, lantacin, camarinin, and ursolic acid, were tested for nematicidal activity against root‐knot nematode Meloidogyne incognita. Pomolic acid, lantanolic acid, and lantoic acid showed 100% mortality at 1 mg/ml concentration after 24 h, while camarin, lantacin, camarinin, and ursolic acid exhibited 100% mortality at this concentration after 48 h. These results are comparable to those obtained with the conventional nematicide furadan (100% mortality at 1 mg/ml concentration after 24 h).

Isolation of nematicidal compounds from Tagetes patula L. yellow flowers: structure-activity relationship studies against cyst nematode Heterodera zeae infective stage larvae.

Bioassay-guided isolation studies on the extracts of yellow flowers of Tagetes patula L. against the Heterodera zeae were carried out to identify phytochemicals lethal to this economically important cyst nematode. In vitro investigation of a polar extract and fractions showing activity led to the isolation of phenolic compounds (flavonoids and phenolic acids). In the nonpolar extract, a few fatty acids, their methyl esters, and thiophenes (including α-terthienyl) were detected. In studies of compounds obtained commercially, α-terthienyl and gallic and linoleic acids showed 100% mortality at concentrations of 0.125% after 24 h. Assessment of structure-activity relationships revealed that an increase in the number of hydroxyl groups in phenolic acids increased the activity; with fatty acids, activity depended on chain length and the number and position of double bonds. Crude extracts of the flowers of different colors also have promising activity.

Chemical constituents of Cordia latifolia and their nematicidal activity.

Following nematicidal activity‐guided isolation studies on the fruits, bark, and leaves of Cordia latifolia, two new constituents, cordinoic acid (=11‐oxours‐12‐ene‐23,28‐dioic acid; 1) and cordicilin (=2‐{[(E)‐3‐(3,4‐dihydroxyphenyl)prop‐2‐enoyl]oxy}‐3‐[4‐hydroxy‐3‐(stearoyloxy)phenyl]propanoic acid; 2) were isolated from the stem and leaves, respectively, together with nine known compounds, namely cordioic and cordifolic acid from the stem bark, latifolicin A–D and rosmarinic acid from the fruits, and cordinol and cordicinol from the leaves. Their structures were determined by means of spectroscopic analyses including 1D‐ and 2D‐NMR techniques. The nematicidal activities of these constituents were determined against the root‐knot nematode Meloidogyne incognita. Hundred percent mortality was caused by all of these after 72 h at a 0.125% concentration. Compound 1 and cordioic acid were most active and caused 100% mortality after 24 h at a 0.50% concentration. Furthermore, compound 2, the ester of rosemarinic acid, was found to be more active than the free acid.

Two new species of Paurodontella Husain & Khan, 1968 (Nematoda: Sphaerulariidae) associated with wheat and a diagnostic compendium to the genus.

An identification key to ten valid species of Paurodontella is given. A compendium of the most important diagnostic characters with illustrations of each species is included as a practical alternative and supplement to the key. The diagnosis of Paurodontella is emended and a list of all valid species of the genus is given. Two new species (Paurodontella myceliophaga n. sp. and P. balochistanica n. sp.) collected around the roots of wheat (Triticum aestivum L.) from North-West Frontier Province and Balochistan, Pakistan, are described and illustrated. Paurodontella myceliophaga n. sp. is characterised by having a short post-uterine sac, lateral field with four incisures, excretory pore at the base of the pharynx and fusiform median bulb, whereas P. balochistanica n. sp. has a longer and very slender body with posterior vulva, lateral field with four incisures and short mucronate tail. Because these species are limited in distribution, their importance is not known.

A new entomopathogenic nematode, Steinernema bifurcatum n. sp. (Rhabditida: Steinernematidae) from Punjab, Pakistan

A new species of Steinernema is described herein as S. bifurcatum n. sp. It is characterised by the presence of a male gubernaculum that is bifurcate at both proximal and distal ends, a key diagnostic feature. Steinernema bifurcatum n. sp. belongs to the bicornutum group by having two horn-like structures on the labial region of the infective juvenile (IJ). It can be recognised by IJ body diam. = 22 (20-24) μm, pharynx = 114 (102-134) μm, ratio a = 24 (22-25) and D% = 39.7 (33-47). The new species can be further recognised by the male characters of D% = 48 (42-58), and genital papillae = 23 (22 + 1) in number and, for the first generation female, excretory pore = 75.7 (60-108) μm, pharynx = 174 (158-200) μm and tail length = 43.2 (38-60) μm. Steinernema bifurcatum n. sp. is distinguished from all other members of the bicornutum group by the presence of a gubernaculum which is bifurcated at both proximal and distal ends in first generation males. On the basis of genital papillae number (22 + 1) it is close to S. abbasi, S. ceratophorum and S. pakistanense, but can be distinguished by morphometrics of IJ and adults. IJ of S. bifurcatum n. sp. can be differentiated from those of S. ceratophorum and S. pakistanense by the smaller body length of 460-590 μm. Steinernema bifurcatum n. sp. differs from S. abbasi by morphological characters of IJ, male and female stages. The IJ can be distinguished by D% (33-47), body diam. (20-24) μm, b value (3.8-5.6) and pharynx length (102-134) μm. The second generation male differs by GS ratio (0.29-0.45) and the mucronate tail. The first generation female is distinguished by a protruding vulva and no postanal swelling. Analysis of ITS rDNA (824 bp), D2-D3 (880 bp) and mt DNA region (507 bp) sequences confirm that the studied nematode isolate represents a valid new species, the combination of molecular and morphological features indicating that it belongs to Clade IV, the bicornutum group.

Steinernema balochiense n. sp. (Rhabditida: Steinernematidae) a new entomopathogenic nematode from Pakistan

A new species of entomopathogenic nematode (EPN) named Steinernema balochiense n. sp. belonging to the family Steinernematidae was isolated from Psidium guajava L., rhizophere soil samples of Balochistan, Pakistan. This new species belongs to the carpocapsae group. The new species can be separated from other described species by morphological and morphometrics characteristics as well as DNA sequence polymorphisms. This new nematode species is morphologically characterized by features of infective juveniles (IJ) and males. For the IJ average body length was (455; 415-528) µm, distance from anterior end to excretory pore (35; 32-38) µm, pharynx length (90; 85-98) µm, tail length (44.3; 40-51) µm, D% and E% values (39; 36-44) and (80; 70-92), respectively. For male specimens, the diagnostic characters included total body length (1330; 1135-1632) µm, gubernaculum length (44.4; 40-47) µm, D% (43.8; 40-51) and ratio of GS (63.8; 53-75). Morphological diagnostic traits for new species include the presence of a funnel shaped gubernaculum at the proximal end. S. balochiense n. sp. differs from infective stage juveniles of closest species S. nepalense by having 6 ridges vs 7 ridges in the lateral field. Molecular phylogenetic trees based on sequence of ITS-rDNA, D2D3 regions and the mitochondrial 12S rRNA gene supports the description of this nematode isolate as a new species.

Nematicidal Triterpenoids from Lantana camara

A new triterpene, lancamarolide (1), and seven known triterpenes, oleanonic acid (2), lantadene A (3), 11α‐hydroxy‐3‐oxours‐12‐en‐28‐oic acid (4), betulinic acid (5), lantadene B (6), and lantaninilic acid (7) were isolated from the aerial parts of Lantana camara in the course of bioassay‐guided isolation, and their nematicidal activities against Meloidogyne incognita, the root knot nematode, were carried out. Oleanonic acid was found to be the most active compound and exhibited 80% mortality after 72 h at 0.0625% concentration, which is comparable with that of the standard furadan.