Options for converting a clone trial of Eucalyptus camaldulensis into a clonal seed orchard considering gain,fertility and effective clone number

We evaluated a clone trial comprised of 20 ramets each of 40 Eucalyptus camaldulensis clones for growth and fertility at 4 years of age. The clones differed significantly in growth with 65-100 % survival in 38 clones while two clones had low survival （40 and 10 %）. Fecundity was high and fertility variation low, as indicated by the sibling coefficient value （ψ = 1.4） with 55 % of clones contributing 80 % of the fruits. Thinning strategies were considered to convert the clone trial to a clonal seed orchard and enhance both gain and diversity in seed crop. When clones were selected based on growth without con- sidering fertility, truncation selection （to retain clones with higher DBH than the trial mean value） would give 8 % gain, but 59 % reduction in effective population size （Ne）. Gain and predicted diversity （Ne） was highest when ramets were selected in linear proportion to the breeding value of each clone. Mass selection with the same intercept （for DBH） as truncation selection would give a moderate 3 % gain, but over two times higher predicted Ne than trunca- tion selection. When fertility of retained trees was con- sidered after thinning, mass selection would yield 52 % effective contribution from the orchard trees compared to only 30 % contribution from truncation selection and linear thinning. Higher representation of superior clones in linear thinning and mass selection would lead to greater fertilityvariation and over 30 % reduction in effective clone number （Nc） from that predicted （Ne, assuming equal fer- tility among ramets） before thinning.

Chemoenzymatic Synthesis of an Enantiomerically Enriched Bicyclic Carbocycle Using <i>Candida parapsilosis</i>ATCC 7330 Mediated Enantioselective Hydrolysis

Enantiomerically enriched (R)-1-(2-bromocycloalkenyl)-3-buten-1-ol and its derivatives were obtained via enantioselective hydrolysis [resolution] with good enantioselectivities (E = 31 to >500) using Candida parapsilosis ATCC 7330. The various reaction parameters were optimized for enantioselective hydrolysis to achieve high enantiomeric excess (ee) and conversions. Among the substrates tested, (RS)-1-(2-bromocyclohex-1-en-1-yl) but-3-yn-1-yl acetate was hydrolysed by the biocatalyst in 12 h to the corresponding (R)-alcohol in 49% conversion and >99 ee. The optically pure allylic alcohol thus obtained was used as a chiral starting material for the synthesis of an enantiomerically enriched bicyclic alcohol effectively establishing achemoenzymatic route.

A Novel Approach for the Synthesis of (R) and (S)-Nicotine

Nicotine is an alkaloid mainly found in leaves of tobacco and is used therapeutically for patients seeking relief from tobacco dependence in the form of products such as gums, patches, lozenges etc. In these products, majorly nicotine derived from tobacco is used which is inherently contaminated with undesirable nicotine related substances as impurities at low levels and is difficult to remove. Hence, use of synthetic nicotine is considered as an option which will be devoid of such impurities. In this work, a short and efficient synthesis of (R) and (S) nicotine was achieved by leveraging a key esterification between racemic homoallylic alcohol intermediate (2) and (S)-Ibuprofen (3) to produce diastereomers (5a) and (5b) which were easily separable under standard column chromatography conditions. Use of (S)-Ibuprofen (3) as a chiral resolving agent constitutes a novel approach which was not reported earlier. A subsequent hydrolysis of the diastereomers furnished the homoallylic alcohol intermediates (S)-6a and (R)-6a with high enantiopurity, which was effectively translated to the corresponding (R)-nicotine and (S)-nicotine respectively.